Introduction to Psychological Science: Integrating Behavioral, Neuroscience and Evolutionary Perspectives - William J. Ray 2021

Consciousness

LEARNING OBJECTIVES

✵ 6.1 Discuss the different levels of consciousness, including attention and awareness.

✵ 6.2 Describe what happens when we sleep and dream.

✵ 6.3 Describe the techniques of hypnosis and meditation.

✵ 6.4 Discuss the three broad categories of psychoactive substances: depressants, stimulants, and hallucinogens

Alan Turing (1912—1954) was an English mathematician who was involved in developing forerunners to the modern computer and their algorithms. He was also involved in breaking the code of the German Enigma machine during World War II. In his work he confronted the question of artificial intelligence (AI) and human thinking. That is, can a machine think? One question that grew out of this work was how do you know if the voice you are talking with on your cell phone has consciousness? And, of course, what does it mean to be conscious? Turing’s life was depicted in the 2014 movie The Imitation Game.

In Turing’s 1950 paper, he developed a game called the imitation game (Turing, 1950). It is played with three people—a man, a woman, and an interrogator who may be of either gender. The interrogator stays in a room apart from the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either, “X is a man and Y is a woman” or “X is a woman and Y is a man.” The interrogator is allowed to put questions to the two. Since the responses are presented via a computer screen and the people are not required to tell the truth, it gave insight into the logic of decision making. What questions would you ask to determine gender?

Alan Turing modified this game to be a person and a computer, and the interrogator had to decide which is which. You could ask any questions you wished to decide which was human and which was computer. Neither had to tell the truth. How would you determine whether the messages you were getting on your computer were from a human or a machine? Are there distinct factors that would help you determine human consciousness from machine responses?

Consciousness

Most people think they understand what consciousness is, but few people can actually define it specifically. Some associate it with the continuous thoughts and feelings that we experience throughout the day. William James referred to this as the stream of consciousness. Like a stream, our ongoing experiences of what we think and feel continue with us always. Psychologists define consciousness as being aware and knowing that you are involved in a particular event.

We also seek ways to modify our consciousness. You listen to certain music because you like the feelings it gives you. You eat certain foods for the feeling of comfort and the memories associated with such meals. Reading a book or watching videos also can change our consciousness. Likewise, drinking coffee or alcohol changes our state of being. You may even seek to reduce your level of consciousness as when you take a nap. At times we may perform yoga or meditation as a way to better experience our internal processes.

A change in the scientific study of consciousness began with the advent of a scientific psychology. Individuals such as William James began to ask questions concerning the function of consciousness rather than its physical properties. James placed consciousness within an evolutionary perspective and sought to describe its function. As such, consciousness was seen as a process that developed as an adaptive mechanism over our evolutionary history that gave benefits to human functioning.

Freud described three types of consciousness, which we will discuss in greater detail in the chapter on personality. One type is what we are aware of, which is generally referred to as conscious awareness. There is also information such as your telephone number that at any moment you could bring into consciousness. Freud referred to this as latent consciousness or pre-consciousness. The third type of consciousness contains information we are not aware of and find difficult to bring into consciousness. However, this state, referred to as unconscious processes, according to Freud can still influence our thoughts, feelings, and behaviors. If, for example, you were in an automobile accident as a child, you might not remember this event but feel anxious or fearful when you ride in certain types of cars.

More recently, with the development of neuroscience techniques for understanding brain function, consciousness has become a more popular topic of scientific study. For example, Francis Crick (whom you met previously for his discovery of the structure of deoxyribonucleic acid (DNA)) and his colleague Christof Koch suggested that the way to understand consciousness is to study the neural correlates of consciousness (Crick & Koch, 2003). This has led to a variety of approaches (Dehaene, 2014; Hameroff & Penrose, 2014; Koch & Greenfield, 2007).

These approaches range from looking at particular types of cells in the brain to the manner in which neural networks can create emerging processes. The first approach seeks to find cells or areas in the brain that once activated lead to the experience of consciousness. This makes consciousness a discrete phenomenon related to specific brain areas. The second approach, as previously described by Hughlings Jackson in the 1800s, spoke of consciousness as a process that emerges from the activity of the brain. That is, consciousness is not the result of a specific brain cell being activated but the result of the entire brain working together. At this point, there is no definite answer as to the nature of consciousness. However, the neural correlates of consciousness continue to be studied (Demertzi et al., 2019; Hahn et al., 2021).

As noted, one aspect of consciousness from an evolutionary perspective is its functional nature. That is, what advantages does it give us? Not all organisms have the same experience of consciousness as do humans. However, like the Turing problem, it is difficult to know what consciousness in non-human animals is like. From an evolutionary perspective, William James saw consciousness as related to selective attention. Attention allows us to focus and prioritize our efforts. As such, there is survival value. We can know where it is safe and where it is dangerous. We can remember the foods that taste good to us as well as those that make us sick. This helps ensure our survival. Additionally, to be able to communicate this information to others helps them survive. This type of sociality also helps us establish a culture.

Consciousness and Attention

In considering consciousness and attention, we realize we are often not totally aware of what we are doing. As we drive on a long trip on the highway, we can get lost in our thoughts. Quite often on long trips, many people let their mind wander and daydream. We let some other part of ourselves take over and do the driving. Are we unconscious at that point? Of course not! If there is a problem, you quickly return to driving. It is almost as if you were unconscious but you were still able to drive the car successfully.

Often at a party we pay attention to those around us and ignore the conversations of others in the room. However, if you were to hear your name mentioned across the room, your attention would go directly to that area. This has been referred to as the cocktail party effect. What these experiences tell us is that we have different systems of consciousness and awareness for living life and making decisions. That is, whether at a party or driving, we are able to monitor other aspects of the environment without being aware of it.

Since having someone space out is not easy to accomplish in a research setting, scientists have sought other situations, mainly visual processes, to study. This allows for more careful scientific control over the setting. One example of such a stimulus is shown in Figure 6-1. If you focus on the “+” the pink dots will begin to disappear.

Figure 6-1 Troxler fading.

What this type of stimulus allows researchers to do is to ask what the underlying brain response is when the dots are in conscious awareness and when they are not. Many different researchers used visual awareness as a way to initially study consciousness in a scientific manner (Crick & Koch, 2003).

Another experimental approach is to use what is referred to as backward masking. The basic procedure is to show a stimulus such as a number on the computer screen quickly. This number could be followed by a blank screen. Generally, the person will say that she saw the number. However, if rather than a blank screen, a series of other stimuli such as letters are presented in the same area as the number, strange as it seems, the person will not report seeing the number.

A critical factor in determining whether the stimulus is seen is how soon after the number is presented the letters are presented. If the time between the number and the letters is over about one-quarter of a second, the person will report seeing the number. However, if the letters are presented before about one-quarter of a second, the person will not be aware of the number. Further, this is an all-or-none effect. Visual awareness does not increase slightly as the time between the number and the letters is increased. When the delay reaches a critical duration, the number is seen. When the delay is less than that, it is not seen.

Stanislas Dehaene and his colleagues at Collège de France in Paris have used the backward-masking approach to ask what happens in the brain when you see the number versus when you do not see it (Dehaene, 2014; Dehaene, Lau, & Kouider, 2017). Using EEG evoked potentials, these researchers showed that when the person is aware of the number, a particular EEG wave form, the P3, is seen. One important area of the brain that showed this EEG change was the prefrontal cortex. Thus, your brain shows a different EEG response with awareness of the stimulus.

Another type of task used to study conscious awareness is a stimulus in which the object seems to “pop out” once it is seen. A number of researchers have become interested in this process (for example, Singer, 2009; Singer & Gray, 1995; Tallon-Baudry & Bertrand, 1999). For example, when you look at the image in Figure 6-2, you may not initially see the Dalmatian dog against the black and white background. When you do see it, there is a subjective experience of having the image “pop-out.” Associated with this perception is a burst of EEG gamma activity. EEG gamma is associated with perception, and when that perception is experienced in conscious awareness, there is enhanced gamma band activity.

Figure 6-2 Dalmatian dog.

Overall, research shows sudden EEG changes in the brain to be associated with conscious awareness. These include evoked potential changes and EEG gamma band activity. In addition, during periods of conscious awareness, the brain forms connections or networks across more areas of the cortex than when conscious awareness is not present. That is, during conscious awareness, more areas of the brain are communicating with one another.

As you go through the day, your brain is solving problems, making expectations, and planning what to do next. In order to do this, different areas in our brain work on their own and in connection with other areas. Of course, our experience is that there is only one of us thinking and feeling. Somewhat amazing, isn’t it. Further, there is no single brain area related to consciousness (Dehaene, 2014; Dehaene, Lau, & Kouider, 2017). As you will see in this chapter, consciousness is the result of the interactions among a number of neural networks in our brain.

Types of Awareness

In terms of attention, we can be aware of something. This is the basic level. We have sensations and create perceptions. For example, we can be aware of a cat. We can know it is raining. We can even be aware of images in our dreams. Sometimes we have a sense of how our self is involved while other times, like watching a movie, our self seems not to be part of our attention.

There is also another level of awareness that is important for humans, which is referred to as meta-awareness. That is, we can be aware of our awareness. I can experience myself watching something else. In conversations, meta-awareness lets us experience ourselves talking as well as having awareness of the other person at the same time. As such we use our awareness systems as a way to plan and direct our actions and cooperate with others. As you will see in this chapter, some individuals are even able to experience themselves having a dream and make changes to it.

As humans we not only have awareness of our awareness but also cognition about cognition or metacognition (Shea, Boldt, Bang, Yeung, Heyes, & Frith, 2014). Nicholas Shea and his colleagues suggest that metacognition is composed of two systems. The first metacognition system functions out of awareness, whereas the second system is able to accomplish a richer number of tasks. System one works quicker and in parallel, whereas system two performs action in a serial form. In playing a video game, system one tells us when we have made a mistake. System two, on the other hand, helps us learn to detect the feelings associated with these errors. It also helps us decide whether someone we are talking with is telling us the truth. We put together a number of clues in terms of their voice, posture, facial expressions, and so forth to make such a judgment. Researchers have shown that brain structure is related to individual differences in making these judgments before this information comes into awareness (Getov, Kanai, Bahrami, & Rees, 2015).

Levels of Consciousness

Not only has consciousness been discussed in terms of what we are aware of, but also our level of awareness. What a given individual is aware of is often seen as a local state, whereas sleep, coma, and wakefulness are seen as global states (Bayne, Hohwy, & Owen, 2016; Fazekas & Overgaard, 2016). Global states are typically measured in terms of cognitive, behavioral, and physiological measures such as eye movement and EEG during sleep. The basic question is how well a person is connected with his or her environment. From this perspective, we speak of levels of consciousness. These levels can be discussed in terms of coma, vegetative state, and wakefulness and awareness (Gosseries, Di, Laureys, & Boly, 2014). Coma typically is the result of stroke, loss of oxygen, or trauma to the head. Coma is characterized by a lack of wakefulness and awareness. A vegetative state is defined as wakefulness without signs of awareness (Laureys, 2005). From this perspective, consciousness can be described in terms of wakefulness and awareness. Between coma and normal consciousness, there is a continuum in which a person varies in terms of awareness and the ability to communicate.

A common procedure that is designed to change the level of a person’s consciousness is the use of anesthesia. In fact, anesthesia changed the nature of medical care and operations in the 1900s. Both Sigmund Freud and William James experimented with different types of anesthesia. At times, they even tested the drugs on themselves.

Today, anesthesia allows for careful changes in a person’s level of consciousness. This has allowed researchers to monitor the return to consciousness as anesthesia is withdrawn from the person. Typically, as the effects of anesthesia wear off, the person begins to respond to sensory processes such as hearing someone’s voice and simple motor processes such as opening her eyes. Combining the ability to control anesthesia with current brain-imaging techniques has opened up new ways to study levels of consciousness.

One study in Finland examined young healthy adults who volunteered to be administered anesthesia (Långsjö et al., 2012). The particular anesthesia used creates a state similar to sleep in that the person can be aroused by touching or hearing someone’s voice without changing the level induced by the drug. Brain activity in terms of blood flow was determined by PET (positron emission tomography).

What these researchers found was that the initial return to consciousness took place in the more evolutionarily primitive areas of the brain. That is, the brain stem, thalamus, hypothalamus, and anterior cingulate cortex (ACC) were the initial areas to respond. There were no changes in the neocortex.

CONCEPT CHECK

1. Most people think they understand what consciousness is, but few people can actually define it specifically. What are three different approaches historically that people have taken to try to study consciousness?

2. We talk about a basic level of awareness when we have sensations and create perceptions about an external or internal event. How do the concepts of meta-awareness and metacognition build on that basic level?

3. What are the three levels of awareness, and what are the distinctive differences between them?

4. What has the discovery of anesthesia taught us about how to describe the levels of consciousness and what happens as we move from one level to another?

Variations in Consciousness

As noted, when we look at an object, we become conscious of what it is. However, it generally takes about a half second before our brain gives us the experience of being aware of what is there. During this time, a large number of brain networks involving billons of neurons process the information. When we shift our attention to something else, the original object leaves our consciousness. In this manner, attention and consciousness are closely related in our everyday language. Although we think of consciousness being related to selective attention, some researchers have suggested that these are two separate brain processes (Koch & Tsuchiya, 2007). Part of their argument is that it is possible to attend to an object without its being consciously perceived. Let us now consider two different long-term conditions in which a person is able to process information without being aware of it—blindsight and being a split-brain individual.

Blindsight

Normal awareness depends on information being passed in both directions between a number of areas of the brain (Paller & Suzuki, 2014). Of course, if there is damage to any of these areas, normal awareness is disrupted. One example of this is referred to as blindsight (Weiskrantz, 1996). Blindsight occurs when there is damage to the primary visual cortex (V1). Although there is damage to the visual cortex, there are still visual pathways going to the subcortical areas. When individuals with this condition are asked what they see, they report seeing nothing.

However, if you were to ask them if they could detect movement from a cursor on a computer screen, for example, they will report seeing nothing but can correctly report the movement. They claim they just “guessed.” Sometimes, they describe a sensation in a nonvisual realm such as a pinprick (Richards, 1973). Further, individuals who show blindsight are also able to discriminate different colors although they say they do not see them (Silvanto, Cowey, & Walsh, 2008). They also can detect emotions in another person’s face (de Gelder, 2010). Thus, the person has no conscious awareness of his or her perceptions but can accurately describe motion, discriminate color, and react to emotions.

One amazing demonstration involving a person who experiences blindsight was created by Beatrice de Gelder and her colleagues (de Gelder, 2010). They studied a doctor who had a number of strokes that left his primary visual area (V1) not functioning correctly in both hemispheres. This person who is referred to in the scientific literature as T.N. is completely blind. What de Gelder did was to fill a corridor with a number of objects. However, T.N. was told that the hallway was empty and that he would not need his cane. T.N. then began to walk down the hallway. Surprisingly, as he walks, he avoids the objects and is able to walk down the hall without walking into them. This demonstration can be seen on YouTube (https://www.youtube.com/watch?v=4x0HXC59Huw). Visual information is still gathered and routed to other parts of the brain, allowing this person to see without seeing.

brain Patients

Another situation in which an individual can process information outside of awareness was first noted in the middle of the last century. In the 1960s and 1970s, an operation was performed to reduce the frequency of uncontrollable epileptic seizures. These operations were performed on individuals who had had severe epilepsy for a number of years and were typically unable to work. The initial operations cut the fiber tract—the corpus callosum—that connects the left and right hemispheres of the brain. By performing this operation, epileptic seizures could not spread over the entire brain. These patients came to be referred to as split-brain patients. Overall, following the operation, these patients showed a drastic reduction in seizures. Surprisingly, cutting the corpus callosum (which contains some 200 million nerve fibers) did not appear to cause any changes in the everyday behavior or experience of these patients.

Before continuing with split-brain patients, let’s consider some basics of brain function. These basics were originally described by Hughlings Jackson in the 1800s. He noted that the left and right hemispheres of the human brain are specialized for different tasks. The left hemisphere is involved in language processing and other serial processes. The right hemisphere processes spatial tasks and other global processes. This is referred to as hemispheric specialization.

Each of your eyes receives information in terms of what you see in front of you. If you imagine a line down the middle of what you see, your image could be divided into a left and a right image. If you don’t move your eyes, what is in the left image (left visual field) goes to the right visual areas at the back of the brain. What is in the right visual field goes to left visual areas (see Figure 6-5). Since it takes a small amount of time to move your eyes, if visual information is presented in less than one-fifth of a second, it initially goes to just one hemisphere. This is faster than anyone’s ability to make an eye movement, which could result in the information going to both hemispheres.

Normally, the left and right hemispheres are able to share information by transferring it through the corpus callosum. However, in the case of the split-brain patients the corpus callosum had been cut. Thus, information could not be transferred from one side to the other.

However, with more extensive experimental procedures, a different picture emerged with the split-brain patient. This work was initially performed by Roger Sperry and his colleagues (see Springer & Deutsch, 1998 for an overview).

Figure 6-3 Brain cut in half front to back.

What Roger Sperry and his colleagues found was that when information was presented to the left hemisphere of the split-brain patients, they reported seeing it and could identify it verbally. If the information was presented to the right hemisphere, the patient would say he saw nothing. However, somewhat more amazing, if asked to point to a series of objects with the left hand, which is controlled by the right hemisphere, he was able to do it correctly. This led Sperry to suggest that split-brain patients contained the equivalent of two minds, each with its own separate consciousness. However, the experience of awareness was connected with the left hemisphere. Although when information was presented to the right hemisphere the person was able to point correctly, like the blindsight person, he did not experience it in his awareness.

Figure 6-4 Parts of normal human brain. Source: Washington University.

Figure 6-5 Left and right visual fields and visual areas.

A related difference between the two hemispheres is whether information is presented as a whole (as would be the case in visual scenes) or made up of parts (as would be the case with language where one word follows another). It is also possible to create images such as Figure 6-6 in which one can focus on the details such as the “S” that makes up the “H” or the “H” itself as a whole. If this image is presented to the left hemisphere of a person with the corpus callosum split, she will say she saw “S.” However, if it is presented to the right hemisphere, she will see the “H.” Thus, the right hemisphere processed in terms of wholes, whereas the left hemisphere processed in terms of individual parts.

Figure 6-6 Large H made up of small Ss.

An intriguing example of the whole versus part dichotomy was performed by Michael Gazzaniga with a split-brain patient he had been following. The patient was shown art by the Italian artist Giuseppe Arcimboldo (c.1530—1593). What Arcimboldo did was to create faces by putting together images of fruit and vegetables (https://www.wikiart.org/en/Search/Giuseppe%20Arcimboldo). When the split-brain person was shown one of these pictures, the person would see a face if the picture was shown to the right hemisphere. However, he would see individual pieces of fruits or vegetables if the same picture was shown to the left hemisphere.

A particularly intriguing outcome of these two minds is the manner in which the conscious verbal left hemisphere appears to fill in gaps in information. That is, if the right hemisphere performed an action out of awareness of the left hemisphere, the person using his left hemisphere would create a story to explain the action. In this research, a snow scene was flashed to the right hemisphere of the patient and a chicken claw to the left hemisphere. The split-brain patient was then shown the pictures presented in Figure 6-7.

Figure 6-7 Split-brain patient creates a story on what he sees.

The person was then asked to point with each hand to an image that was related to what had been seen. The right hand, which is controlled by the left hemisphere, pointed to a chicken. The left hand, which is controlled by the right hemisphere, pointed to a shovel, which would be used to shovel snow. The person was able to observe where each hand pointed, although the verbal left side would not have been aware of seeing the snow scene since it went to the right hemisphere. When asked why he pointed to where he did, his verbal response from the left hemisphere was, “I saw a claw and I picked a chicken, and you have to clean out the chicken shed with a shovel” (Gazzaniga & LeDoux. 1978).

How should we understand this? Gazzaniga and LeDoux suggest that the left hemisphere acts as an interpreter of action and creates views of one’s behavior that fits a consistent scheme. What is more is that these researchers suggest it is not just split-brain patients that do this but all humans. That is to say, it is part of our nature to fill in the gaps and create explanations for our actions. It is assumed that filling in the gaps is the resultant of neural network integration that integrates information from a variety of cortical areas.

Overall, in the case of humans, the resulting specialization is for spatial processing in the right hemisphere and language processing in the left. An intriguing question raised by the split-brain research is how language and awareness became associated with each other. One could also ask the opposite question of why spatial processing, at least in the split-brain patient, appears to exist independent of conscious awareness. We might also speculate that since language is associated with conscious awareness, it came at a later stage in our evolutionary process. As you will see throughout this book, all humans and not just those with the split-brain operation constantly process information outside of normal awareness.

Conscious Awareness

Although most of us have not experienced blindsight or the results of a split-brain operation, we have seen situations in which stimuli disappear from our experience. A simple one is the blind spot in our eye that you learned about in the chapter on perception. Our brain fills in what is missing. Also, when we focus on one aspect of a situation, we miss others. Numerous studies have shown that if you pay attention to texting on your phone, you lose awareness of what is going on around you. This is, of course, a problem if you are driving.

One of the most famous studies concerning environmental awareness was performed by Daniel Simons and his colleagues (see Chabris & Simons, 2010 for an overview). This phenomenon is referred to as the invisible gorilla (http://www.theinvisiblegorilla.com/gorilla_experiment.html). In the video you are asked to watch six people pass a basketball back and forth. Three of the people have white shirts and three have black shirts. Your job is to count the number of passes made by the people in the white shirts. At one point in the video, a gorilla walks into the scene, faces the camera and thumps its chest, and then leaves. In all, the gorilla is in view for 9 seconds. Surprisingly, when this study was performed at Harvard University, about half of the participants reported not seeing the gorilla.

The World Is Your Laboratory—Out-of-Body Experiences

Throughout history individuals have described the feeling of being out of their body. This has been associated with spiritual experiences and other exceptional situations. Some individuals who experience trauma such as sexual assault also report out-of-body experiences in which they report watching the assault happen to them.

Often the description is one of the person being above the situation and looking down upon what is happening. Typically, three characteristics are present with out-of-body experiences. The first is the sense of self being outside of one’s body. The second is the experience of seeing the world from above. And third, the experience of seeing one’s own body.

Many people are skeptical and think that any talk of out-of-body experiences is crazy. They dismiss the idea that our sense of self can be experienced other than within our bodies (Blanke & Arzy, 2005). Although out-of-body experiences have been associated with clinical problems such as epilepsy, it has been reported by 10% of healthy populations. More recently, researchers have begun to explore the nature of this phenomenon scientifically (Blanke, Landis, Spinelli, & Seeck, 2004).

Our normal experience of our body is the result of an integration of information related to our position in space, our balance, what we view, and the internal feedback from our body. Normally, we have a sense of ourselves based on this information. In terms of our brain, the area between the frontal and temporal lobes, referred to as temporoparietal junction (TPJ) is associated with our location in space from a first-person perspective (Ionta, Martuzzi, Salomon, & Blanke, 2014). Current theory suggests that it is a lack of integration related to this information that produces the out-of-body experience.

One initial approach to understanding out-of-body experiences was to examine individuals with brain damage who reported having the experience of being outside of their body (Blanke & Arzy, 2005). Brain-imaging techniques showed that the location of the lesions or damage in these patients also was at the junction of the temporal and parietal lobes, or TPJ.

Amazingly, Olaf Blanke and his colleagues in Switzerland were able to produce out-of-the body experiences by electrical stimulation (Blanke, Landis, Spinelli, & Seeck, 2002). The person involved was a 43-year-old women who had epilepsy. During operations for epilepsy, the person remains conscious as the surgeon stimulates different areas of the brain to determine its relation to function so as not to operate in an area of critical importance such as language. As shown in the figure, stimulation of different areas of the brain results in different experiences. At one point, when the surgeon stimulated the areas shown in yellow, the woman said that she felt like she was falling or growing lighter. Then she said, “I see myself lying in bed, from above.” All this, just from stimulating an area in the brain.

In what is the first of its kind, a 24-year-old reported that she could produce an out-of-body experience in herself. In fact, she thought everyone could. She first had these experiences as a child when required to take a nap that she did not want to do. At this time, she discovered that she could elicit the experience of moving above her body. She later used these out-of-body experiences to help her move into sleep. Andra Smith and Claude Messier at the University of Ottawa studied this person using fMRI. They found a number of brain areas activated during the self-induced out-of-body experiences (Smith & Messier, 2014). These included areas overlapping the TPJ, the cerebellum, which is consistent with the experience of movement reported, and other areas associated with action monitoring. Control tasks in which she imaged doing other movement activities resulted in different areas of the brain being activated than those seen in the out-of-body experience.

Modern brain-imaging techniques have given scientists new ways to study uncommon experiences whose existence has been denied.

Thought question: What three characteristics are normally present in people’s descriptions of their out-of-body experiences? How have brain-imaging techniques given scientific support to these personal observations?

CONCEPT CHECK

1. What brain changes occur in an individual with blindsight? What specific evidence is presented that a person with blindsight is able to process information without being aware of it?

2. What brain changes occur in a split-brain individual? What specific evidence is presented that a person with a split-brain is able to process information without being aware of it?

3. What is meant by hemispheric specialization? What has research with split-brain individuals taught us about how everyone’s brain hemispheres process information differently?

4. What is the “invisible gorilla” phenomenon? What other similar examples from everyday life can you offer?

Sleep and Dreams

What normal process involves one-third of your life? The answer of course is sleep. If you were asked to describe your state of consciousness during sleep, what would you say? You might initially say you were not aware of anything, yet some nights you experience lots of activity through dreams. Although asleep, we all have had the experience of incorporating sounds from around us during sleep into our dreams or waking up with a startle to an unfamiliar sound. Although sleep represents a stage of diminished consciousness, there is much going on in your brain.

We are just beginning to understand the various processes that go on during sleep. With sleep comes a change in muscle tone, hormonal levels, eye movement, and brain activation. We know that after sleep we feel we have more energy. Sleep is also related to our body temperature, which goes down during the night. In terms of the brain, sleep is not the absence of cortical activity, just a different type of highly organized activity (Adamantidis, Gutierrez Herrera, & Gent, 2019; McCormick & Westbrook, 2013).

If sleep is prevented, then intrusions of sleep are seen in our waking day. Since our bodies seek to make up for lost sleep, this suggests that sleep plays an important role in our lives. Without sufficient sleep, performance on tasks is degraded. This has been shown in a number of cases of people who go without sleep. For example, pilots who fly emergency medicine helicopters with their immediate response to emergencies show signs of stress connected with lack of rest (Samel, Vejvoda, & Maass, 2004). Overall, sleep deprivation triggers a complex set of brain changes, which results in problems in attention, memory, and emotional processing (Krause, Simon, Mander, Greer, Saletin, Goldstein-Piekarski, & Walker, 2017). One event that happens during sleep is the removal of waste products in the brain (Nadergaard, 2013). With long-term lack of sleep, these waste products can lead to a number of disorders including Alzheimer’s disorder.

As you can imagine, most human studies of sleep deprivation are of a short-term nature. However, there are a few examples of lack of sleep that lasts for more than a few days. One of these cases is that of Randy Gardner who sought to go without sleep as a science project when he was in high school in San Diego.

Randy sought to stay awake for 11 days to beat the Guinness world record as well as record cognitive activity for his science project. With the help of two friends, he went for 11 days without sleep. His experience was reported by sleep researchers including an EEG when he slept for the first time (Ross, 1965). By the second and third day without sleep, Randy had problems focusing his eyes and performing cognitive tasks and remembering new information. Also, his mood became more negative. Near the end of the 11 days, he had trouble finishing sentences and even experienced some hallucinations and delusions such as mistaking a street sign for a person. He also thought that he was a famous football player, although he weighed only 130 pounds at the time (http://www.esquire.com/lifestyle/a2527/esq0804-aug-awake/).

Randy described his experiences to the magazine Gelf as follows: “The only reason I got through it was because I was a kid. We got halfway through the damn thing and I thought ’Holy s⋆⋆⋆, this is tough. I don’t want to do this anymore.’ But everybody was looking at me at that point so I couldn’t quit” (http://www.gelfmagazine.com/archives/sleeping_in.php). How did he do it? Gardner says he didn’t even drink coffee. “It’s mind over matter,” Gardner said. “Your body will shut down. If you don’t override it with your mind, you’re f⋆⋆⋆ed. You’re going to sleep. You’re gone.” So he kept his juices flowing by playing game after game of basketball with his friends and the sleep researcher William Dement. Dement also drove him and his friends around in a rented convertible. Randy performed several cognitive studies during the sleepless period that were the basis of a winning science-fair project.

Although Randy stayed awake to set a Guinness World Record, a number of individuals who perform various types of shift work experience sleep deprivation that results in fatigue and a reduction in performance. This has been referred to as sleep debt. A number of studies have sought to determine if it is possible to “bank sleep” prior to shift work, which would improve performance (Rupp et al., 2009). Banking sleep refers to extended time asleep prior to a period of anticipated sleep loss. Several studies have shown that banking sleep can improve performance as well as emotional mood (Patterson et al., 2019).

Although we all experience the need for sleep, you might be surprised to learn that we actually don’t fully understand the function of sleep. As you will see in this chapter, sleep serves a number of functions. Our experience tells us that sleep is a strong drive and related to restoring our bodies in terms of energy and alertness. Thus, metabolic processes during sleep prepare us for the next day. As you will see later in this chapter, sleep also strengthens learning and memory. As you read in the chapter on development, the need for sleep is critical for the adolescent brain during a period of cortical development (Galván, 2020).

Evolutionary perspectives tell us that sleep may be protective and keep the organism out of danger. You will also learn in this chapter that animals that eat large amounts of plants sleep less than those who eat meat.

Sleep Patterns

Sleep patterns also evolved in terms of sensory systems. Humans and other animals that use vision as the primary way of finding food and interacting with the world sleep at night. On the other hand, animals such as rats that use nonvisual systems for dealing with the world tend to sleep in the day and look for food at night. As you will also see in the chapter, there are different types of sleep and that these different types of sleep involve different brain areas. One implication is that different types of sleep serve different purposes in the brain. We know, for example, that sleep is important for helping us remember information that we learned during the day.

Sleep became easier to study scientifically in the 1950s. Nathaniel Kleitman and his student Eugene Aserinsky at the University of Chicago published the first detailed account of the patterns of sleep (see Aserinsky & Kleitman, 2003 for a reprint of their 1953 research). What they documented was that during sleep there are periods in which the person’s eyes were still. However, at some point during the night, the person’s eyes—although closed—would move quickly. They referred to this as rapid eye movement or REM sleep. When individuals were wakened during REM sleep, they were more likely to report having a dream than if wakened during quiet sleep.

Another researcher in this University of Chicago lab, William Dement, was able to show that during REM sleep, the EEG looked very different than during quiet sleep. The EEG actually looked more like that seen in wakefulness. Because of this, REM sleep is also referred to as paradoxical sleep. EEG measures during sleep helped to establish that sleep is made up of a set of recurring patterns that we now call stages (Adamantidis, Gutierrez Herrera, & Gent, 2019).

In 2007 and 2016, the American Academy of Sleep Medicine modified the sleep scoring system based on research (see Berry et al., 2015). Their American Academy of Sleep Medicine Manual for the Scoring of Sleep and Associated Events describes non-REM (N) and REM (R) stages of sleep. Thus, stage 1 and stage 2 are referred to as N1 and N2. Stage 3 and 4 are combined and referred to as N3 or slow wave sleep. In the scientific literature, you may see either the older stages 1—4 and REM sleep system or the newer N1—N3 and REM designation.

What do these stages of sleep represent? As you begin to become sleepy, your EEG shows a pattern associated with relaxation, such as alpha waves. The transition from being awake to the onset of sleep varies in different people. Those who fall asleep easily move from being drowsy to the stage 1 of sleep in a few minutes. In stage 1 slower EEG patterns such as theta activity are seen. The move to stage 2, which is the first true stage of sleep, is characterized by sleep spindles and K complexes (see Figure 6-8). During this stage your mechanisms of arousal are reduced, including a real reduction of muscular activity. It is also during this stage that your breathing becomes slower and your body temperature begins to drop. In stage 3, the EEG shows high amplitude and slow frequency waves referred to as delta activity. These are increased in stage 4 sleep. Also, the long-range connections between areas in the brain change to more local connections. The movement from stage 1 to the end of stage 4 takes about 45 minutes.

Figure 6-8 Stages of sleep.

Figure 6-9 Sleep cycles during the night.

During the next 45 minutes, the sleep stages go in the opposite direction. That is, the stages go from stage 4 to stage 1 with most of this time being in stage 4. Although it may appear that the person is moving toward becoming awake, this is not the case. Following stage 4 and a quick movement through stages 3, 2, and 1 is a period of REM sleep. Not only are dreams seen during REM sleep, but there are also physiological changes. In particular, there is an increase in cortical activity but a decrease in the person’s temperature and metabolism. There is also a loss of muscle tone that inhibits movement during dreams. However, during REM, penile erections occur in men and in women clitoral engorgement is present. The purpose of these changes during REM is still a matter of debate. After a REM period, the person goes through another series of sleep cycles. These 90-minute cycles continue throughout the night although the deepest sleep is experienced in the early cycles. The first REM period tends to be of shorter duration than later REM periods. Overall, REM sleep in adults is present during about 25% of the night.

Sleep Changes Across the Lifespan

Human adults sleep for about 8 hours every 24 hours. This is a daily or circadian rhythm. Circadian comes from Latin and can be translated as “about a day.” Thus, a circadian rhythm is a cycle that happens each day as with adult sleep patterns. However, it takes about 12 years for that to happen in humans. With newborn human infants, there is an irregular sleep/wake pattern of which some 50% is spent in REM sleep. By the time the infant is about 3 months old, he or she develops regular rhythms and sleep is seen more often at night. Later, at about one year of age, this changes to a nighttime sleep period and two naps during the day. About the age of two the two daytime naps change to one nap. During the first five years of life, sleep duration ranges from 10 to 16 hours a day, not counting the few months immediately after birth (Galland, Taylor, Elder, & Herbison, 2012). Even though REM sleep is seen in infancy (Hobson, 2009), the ability to recount dreams appears to develop after 5 years of age.

By school time, the afternoon nap has disappeared on a regular basis although children of this age will fall asleep when tired. At puberty, the sleep/wake cycle changes, as does brain development. Recent studies suggest that the sleep cycle of teenagers changes such that they go to sleep and wake up at a later time. In fact, when schools have started later to reflect this change, improvement is seen not only in schoolwork but also in other areas such as a drop in automobile accidents.

Young adults show a predictable pattern of sleep. This pattern, as described previously, occurs in terms of sleep cycles of 90 minutes. In young adults, the first period of REM sleep is usually the shortest of approximately 5 minutes (Raju & Radtke, 2012). Overall, a young adult spends 75% to 80% in non-REM and 20% to 25% in REM sleep. As one ages, the number of arousal and awaking events increase such that older adults may need to spend more time in bed to obtain the same amount of sleep as the young adult.

Figure 6-10 Sleep/wake cycles in different ages.

Stability of Sleep Cycles

Across species including humans and other animals, there is a sleep/wake cycle related to Earth’s day/night cycle. With access to the sun, there is a stable sleep/wake cycle (see Figure 6-11). An environmental factor such as the sun, which influences a circadian rhythm, is referred to by the German word zeitgeber, roughly translated as time encoder or synchronizer. This circadian or 24-hour rhythm has been shown to be fairly stable even in species such as those that live in the Arctic with continuous daylight in part of the year (Golombek & Rosenstein, 2010). There are, of course, many clues to the change in seasons and the 24-hour rhythm as Earth rotates in its yearly movement around the sun. This suggests an evolutionary and genetic contribution to circadian rhythms controlled by a set of neurons in the brain.

Figure 6-11 The sleep/wake cycle remains constant (top of figure) when environmental factors such as the sun are available. Without such environmental cues, the sleep/wake cycle increases by about 2 hours to a 26-hour day (bottom figure).

Over the past 50 years, scientists have asked what would happen if humans had no access to environmental cues that determine sleep/wake cycles. This was studied in what are called cave studies in which humans lived in caves or rooms without windows that would reflect whether it was day or night. Individuals lived alone in these rooms for a period of time, usually a few weeks, without clocks, radios, and other ways of knowing the time of day. These individuals were able to eat as they wished and to sleep and wake as they wished. As shown in Figure 6-11 what happened without access to the sun was that the 24-hour sleep/wake cycle slowly increased by about two hours over a three-week period. What was originally a 24-hour day became a 26-hour day. As soon as these individuals returned to the normal day and night environment, their sleep/wake cycle returned to normal. These studies tell us that our bodies continue a similar sleep/wake cycle even without external cues such as the sun rising and setting.

Sleep Patterns Across Species

Humans are not the only species that sleeps. In fact, it is suggested that animals showed sleep patterns over evolutionary time related to metabolic functions (Anafi, Kayser, & Raizen, 2019). One characteristic across mammals is that sleep represents a quiet time that reduces energy expenditure. There are also postures associated with sleep across species. Humans lie down. Bats hang upside down. Some birds sleep standing up. Cows and horses can also sleep standing up, but they generally choose not to. Sleep is also a state that can be changed quickly. Loud sounds or physical contact will change the sleep state to a waking state.

As with humans, sleep can be determined in animals by using EEG along with observable measures such as posture. Some animals such as bats sleep almost 20 hours a day, whereas other species such as kangaroos sleep as little as an hour and a half a day (Campbell & Tobler, 1984).

Nonhuman primates tend to sleep the same amounts of time as humans. It is assumed that sleep patterns evolved in relation to body size and danger. That is, animals that cannot hide, such as elephants, cattle, or giraffes, sleep less, whereas bats who can hide in dark caves sleep more. Other animals such as lions with fewer predators also sleep more. One study showed that body size and danger accounted for 80% of the variability in sleep time across species (Allison & Cicchetti, 1976). As shown in Figure 6-12, the more an animal weighs, the less it sleeps. It should be noted that this rela-tionship is seen only in animals that do not eat meat. Meat eaters show little relationship between body weight and sleep duration.

Figure 6-12 Length of sleep each day in relation to the weight of the animal.

In terms of insects and fish, there is less evidence that they meet the common definition of sleep (Siegel, 2008). Marine mammals such as dolphins, seals, and porpoises show sleep patterns that affect only half of their brain at a time. That’s right, only one hemisphere at a time. This allows dolphins, for example, to stay awake for as long as 15 days at a time (Branstetter et al., 2012). This can increase the animals’ survival skills. As shown in Figure 6-13, EEG is different in one hemisphere from the other during sleep.

Figure 6-13 EEG from beluga whale during sleep. Note that the hemispheres alternate sleep patterns.

One study examined human sleep patterns in some 20 countries (Walch, Cochran, & Forger, 2016). What these researchers found was that bedtime did differ by country, although these differences became less as a person aged from less than 30 years old to more than 55 years old. Sunrise and sunset also influenced bed and wake time. However, the actual duration of sleep was similar and averaged about 7.9 hours with a mean variation between 7.5 and 8.1 hours across the 20 countries. Thus, cultural factors can play a role in sleep patterns but not the actual amount of sleep one experiences.

Learning During Sleep

Although sleep is seen throughout the animal kingdom, its exact function is largely unknown. One role that is being explored is the manner in which sleep is involved in learning and memory (Paller, Creery, & Schechtman, 2021; Wamsley & Stickgold, 2011; Wamsley & Stickgold, 2018). In specific, sleep benefits memory in humans. In one study, college students who dreamed about a task they had just learned performed better on the task after sleep (Wamsley & Stickgold, 2019). It is also known that a good night’s sleep before a test improves performance. Even trying to move up a level in a video game will be easier the next day compared with the previous night.

Figure 6-14 Average sleep amount for different species.

It is suggested that improved learning after sleep involves a reactivation of memory traces through changes in the connection of synapses (Frank & Cantera, 2014). That is, as noted previously, with new abilities and information come changes in the number of synapses and changes in their connections. Forgetting (or extinction) is associated with the elimination of existing connections. In sleep, neurons involved in activities during the day are reactivated, which strengthens the connections between neurons. Further, EEG slow wave activity during sleep has been shown to increase performance on cognitive tasks the next day. In this manner, sleep promotes learning. It has also been shown that depriving organisms of sleep will prevent or reduce the quality of memory consolidation and learning.

Using a state-of-the-art technique that allows researchers to view neurons in the mouse brain, Guang Yang and his colleagues examined the role of sleep in learning (Yang, Lai, Cichon, Ma, Li, & Gan, 2014; see also Euston, & Steenland, 2014). In this study the researchers trained mice to run on a spinning rod. This of course is not an easy task and takes practice. After this learning, changes in the neurons were examined. They found that after the mice learned to run on a spinning rod, changes in the spines on the dendrite were increased. Spines on the dendrite allow for enhanced connections with other neurons. If the mice also learned a different task, different new spines were found. This suggests that learning different skills produce changes in different parts of the dendrites of the neuron. If the animals were not allowed to sleep following the learning of the new task, then the number of new spines on the dendrites were reduced. However, with sleep, the newly formed spines were still present one day later.

As shown in Figure 6-15, there are three related processes involved in the manner in which sleep enhances learning. The first is slow-wave oscillations in the electrical activity of the brain. EEG slow-wave activity has been shown to be important for learning new information. The second is reactivation during sleep of those neurons that were involved in the learning of the task during the day. In this way the brain repeats the patterns of activity associated with the task. And third, there is an increase in spines on the dendrite, which allows for connections with other neurons. Although this study taught the mice a new skill, other studies with humans have shown that sleep improves the learning of events and places as well. It is actually better for you to sleep before a test rather than do an all-nighter. Of course, you have to read the information first.

Figure 6-15 Sleep processes that increase performance. The three phenomena that increase memory enhancement are: slow-wave oscillations in brain electrical activity, reactivation of recent experiences, and changes in synaptic connectivity.

Neuroscience Studies of Sleep

Since sleep represents a special state of consciousness, some scientists suggest that it can give us a window into understanding consciousness (Hobson & Pace-Scott, 2002; Hobson, 2009). From this standpoint, the three processes of wakefulness, REM sleep, and non-REM sleep represent three different states of consciousness. Each of these states involves different brain and other physiological processes. Over the past 100 years, studies of sleep with humans and animals have painted a consistent picture of the physiological processes involved in sleep and wakefulness.

In the 1940s, Horace Magoun and Giuseppe Moruzzi found that stimulating neurons in the region of the pons and the adjacent midbrain in animals caused a state of wakefulness and arousal (Moruzzi & Magoun, 1949). We now know that this area is also active during REM sleep. This area of the brainstem has since been referred to as the reticular activating system or RAS. Thus, stimulation of the brainstem results in arousal of the forebrain. The opposite situation was found at about this time by Walter Hess in Switzerland. He showed that stimulating the thalamus with low-frequency electrical pulses in an awake animal produces slow-wave sleep. We now know that the basic sleep/wake cycles are under the control of the hypothalamus, the brain stem, and the lower part of the frontal brain.

Figure 6-16 Brain regions of interest in the neurobiology of sleep. The blue boxes represent areas that are key to the generation of the EEG rhythms of sleep, the subjective experience of sleep mentation or dreaming, and sleep’s effects on cognition. The subcortical regions (cream-colored boxes) constitute the loci of control for the regulation of sleep—wake transitions and the control of REM—NREM alternation.

The hypothalamus is involved in circadian rhythms and the onset of sleep. The pons, which is located below the thalamus on the brain stem, is related to changes in REM and non-REM sleep. In particular, neurons in the pons are active both during waking and REM sleep. Their activity is related to the type of EEG seen during the awake state. During non-REM sleep, these neurons are inactive. The subjective experience of sleep mentation or dreaming is related to the limbic areas, the visual areas, and the forebrain. Sleep’s effects on cognition and memory are related to the hippocampus. During sleep the thalamus serves as the gatekeeper and prevents certain information going to the cortex. It also relays information from the RAS and influences EEG changes during sleep. Besides sleep, the thalamus also functions as a control switch in other states of consciousness such as coma and general anesthesia (Picchioni et al., 2014).

One part of the hypothalamus, the suprachiasmatic nucleus (SCN), works as a pacemaker to control the circadian rhythm. Part of the reason we know this is that if there is damage to the SCN, then an animal will still sleep, eat, drink, and exercise. However, there will no longer be a regular pattern to their activities. Thus, the suprachiasmatic nucleus is important for making activities regular. In a number of animals, the SCN also is involved in determining which seasons mating takes place. Deer, for example, mate in the spring and fall of the year.

Figure 6-17 Changes in melatonin, cortisol, and temperature during the night.

The name of the SCN refers to where it is located. Nucleus refers to a group of cells. In the case of humans there are about 48,000 neurons in the winter and 30,000 in the summer in the SCN (Hofmann & Swaab, 1992). The suprachiasmatic nucleus of the hypothalamus is located above (supra) the optic chiasm (chiasmatic). This is the place in the brain where the pathways from each eye cross to go to each hemisphere. Light influences the retina and then the SCN. Part of this process is to cause the pineal gland to decrease the production of melatonin in the morning and to increase it in the evening to induce sleep.

Your temperature falls during sleep and then increases as you wake up (Abbott, 2003). The two hormones, melatonin and cortisol, increase during sleep. Those individuals who produce less melatonin such as the elderly have more disturbed sleep. Some people also take melatonin medications to promote sleep on long-distance airline flights. Exposure to bright light during the day will also increase nighttime melatonin levels and promote better sleep.

Brain-imaging techniques such as fMRI show the manner in which cortical networks are involved in sleep (Picchioni, Duyn, & Horovitz, 2013). First, it is clear that the brain continues to be active in sleep even without external stimulation or self-control of our thoughts. Second, sleep is controlled by bottom-up processes involving the brain stem and the hypothalamus. Third, during sleep some of the same networks such as those involved in memory, arousal, and consciousness are active. In fact, different memory systems are seen to be active during different types of sleep. Fourth, during sleep the frontal areas of the brain are not connected to other areas of the default network (Horovitz et al., 2009). The loss of connection to the frontal areas is one reason our dreams can be irrational or even chaotic. Without logic, you can dream anything you want.

Figure 6-18 Brain regions of interest in the neurobiology of sleep. The top part of the figure shows areas of the brain that are activated (cream color) or deactivated (dark red) in REM sleep. The bottom part of the figure shows changes in the brain (from bottom to top) as sleep stages change from waking to REM sleep; from non-REM to REM sleep; and from REM sleep to waking.

Sleep Disorders

Complaints concerning sleep are second only to those concerning pain in terms of physician visits (Mahowald & Schenck, 2005). In the medical and psychological literature, more than 100 different sleep disorders have been described. However, most of these can be discussed in terms of four broad categories. These four are (1) insomnia, the difficulty to fall or stay asleep; (2) hypersomnia, that is, the experience of excessive daytime sleepiness without obvious explanation; (3) circadian rhythm disorders, that is, the inability to sleep during the desired time; and (4) parasomnias, which include sleepwalking, sleep talking, and night terrors.

Insomnia is the most common sleep disorder seen by professionals. It is described in terms of the inability to obtain enough sleep to leave one feeling rested. Historically, it was believed that insomnia was always the result of an underlying psychological or medical problem. That is, you took your problems to bed with you.

More recent research suggests that insomnia can be present without psychological or medical disorders. Although health disorders can contribute to insomnia, genetic factors also play a role. Further, those with insomnia may actually be more active during the day and have a higher metabolism, which influences their ability to fall asleep. Both behavioral treatment and medications have been shown to be effective. Surprisingly, if some sleep medications are taken for a long period of time, they will actually prevent sleep rather than make it possible. Melatonin is also useful in those individuals whose pineal gland does not produce enough of the hormone.

The second class of sleep disorders is referred to as hypersomnia or lack of sufficient sleep. There are a number of causes of these disorders. Working three jobs or not having time to obtain sufficient sleep leaves one feeling tired. The problem for society in relation to this condition is that a number of automobile, aircraft, and industrial accidents have been linked to lack of sleep on the part of the operators.

Some neurological disorders such as narcolepsy cause the individual to fall asleep at random times during the day. Narcolepsy affects about 1 in 2,000 individuals. Even when standing, the person may experience a sudden case of muscle weakness and fall to the ground in a state of apparent sleep. These individuals enter REM sleep from wakefulness without going through non-REM sleep. These attacks can last from less than a minute to some 30 minutes. When they awake, they may experience their body as paralyzed and be unable to move. This disorder has a strong genetic component and is not related to the amount of sleep obtained at night.

The third type of disorder is circadian rhythm disorders. These disorders result in the person being unable to sleep at the desired time. However, once the person falls asleep, they experience the normal sleeping pattern. A shift in one’s circadian rhythm can be the result of situational factors. For example, flying to a different time zone can result in “jet lag” in which the person experiences sleep patterns that are not consistent with the day/night periods of that location. In general, it takes one day for each hour of time change for a person’s body to adjust. Also, shift work in which a person works the day shift and then the night shift without time to adjust will also influence one’s internal circadian rhythms. In addition to situational factors, there are those who find it difficult to fall asleep before 1 a.m. or 2 a.m. However, they sleep in a normal pattern and wake later in the day. Researchers have been interested in differences in those who are early risers as compared to late risers.

The fourth category of sleep disorders is parasomnias. These are a variety of conditions that may leave the person feeling distressed or bring distress to others. In general, these disorders are not related to one another from an underlying physiological or psychological standpoint. One type of distress occurs when a person experiences consciousness but is unable to move his muscles. This is referred to as sleep paralysis. Normally in sleep, you lose consciousness and then lose the ability to move your muscles. When awaking, the opposite happens. You regain the ability to move your muscles and then regain consciousness as you wake up. However, if you gain consciousness before you can move your muscles, you experience sleep paralysis. You find yourself unable to move and you are aware of that fact. Although this typically is a short-term event, it causes distress, especially on its first occurrence.

Another sleep disorder is called night or sleep terrors (Pavlova & Abdennadher, 2013). The peak prevalence of the disorder is 5 to 7 years of age. This is when the child sits up in bed and begins to scream. It usually occurs in stage 3 sleep and lasts for less than a few minutes. Once the episode is complete, the person returns to sleep and generally does not remember the event the next day. Individuals experiencing a night terror are difficult to arouse. Actually waking the person can prolong or intensify the episode. It is not limited to nighttime sleep but can also occur in daytime naps. The disorder is not related to dream content or other psychological factors. It can be seen in young children, which of course upsets their parents. Typically, the experience of sleep terrors begins before adulthood but can continue into adulthood.

Another parasomnia is sleepwalking (Ralls & Grigg-Damberger, 2013). Sleepwalking has been described in Shakespeare’s plays and continues to be of interest to sleep researchers (Zadra & Pilon, 2011). Although sleepwalking was originally seen as a dissociative state without memory, current research suggests that at least half of the individuals can recall some events on occasion. The emotional experiences during sleepwalking can range from neutral emotionality to agitation. It typically occurs during non-REM sleep and lasts for about 15 minutes, although longer episodes have been reported. If the actions occur during REM sleep, it is referred to as REM sleep behavior disorder.

One example of sleepwalking occurred in a 31-year-old woman. She was found walking up the street in front of her home in her nightgown with a knife in one hand and an unopened package of deli ham in the other (Ralls & Grigg-Damberger, 2013). When examined, she was found to have a history of sleepwalking throughout her life. One confusing problem for those observing sleepwalking is that the person doing the walking may have her eyes open and not initially seem to be asleep. In adults, another problem with sleepwalking is the occur-rence of accidents that lead to physical problems. Sleepwalking runs in families and appears to have a genetic component. Further, sleepwalking activity and the performance of complex behaviors during sleep has been linked to certain medications.

The comedian Mike Birbiglia was on tour in Washington State when he had a dream that a guided missile was heading toward his hotel room. In his dream he jumped out of his hotel room. Although asleep, he actually did jump out of his hotel room. Fortunately for him, he was on the second floor and lived to tell about the event, which he did in a book and movie called Sleepwalk with Me. After the hotel event, he saw sleep professionals and was diagnosed with REM sleep behavior disorder (http://www.npr.org/templates/story/story.php?storyId=130644070 and https://www.cnn.com/2012/10/02/health/sleepwalking-rem-behavior-disorder/index.html). Mike Birbiglia, while asleep, acted out a dream and jumped from his hotel window.

Two other common sleep phenomena are sleep talking and sleep jerks or starts (Weiss, 2013). Although these are not sleep disorders, they can be of concern especially to parents of young children. Sleep talking can range from just a few words or sounds to long speeches of understandable content. Although many young adults have had roommates who sleep talked, most do not remember what they said the next morning. Sleep talking does not occur at any particular stage of sleep. It also tends to decrease as one enters adulthood. Studies suggest that sleep talking is found worldwide and occurs in about one-quarter to one-half of all children at least once a year.

As you fall sleep, it is not uncommon to feel your body jerk for a second. Sleep starts or jerks are seen at the onset of sleep. These are brief contractions of the legs and arms and are experienced as body jerks that last for just a few seconds. These jerks are experienced by some 60 to 70% of the general population. Although they are seen in both children and adults and are normal occurrences, they may concern some parents who mistake them for some type of seizure. Sleep that starts with jerks may awaken the person.

CONCEPT CHECK

1. What is rapid eye movement (REM) sleep, and why is it important for sleep researchers?

2. In what ways does the pattern of sleep change throughout the lifecycle?

3. With access to the sun, there is a stable sleep/wake cycle related to Earth’s day/night cycle. What happens when humans have no access to environmental cues in terms of sleep/wake cycles?

4. Humans are not the only species that sleeps. What factors account for similarities and differences across species?

5. Research has shown that sleep is involved in learning. List three results that support the importance of sleep for learning.

6. Briefly describe the four broad categories of sleep disorders and give an example of each.

Dreams

Another aspect of sleep is dreaming. Dreams that are experienced during sleep reflect mainly involuntary images, ideas, feelings, and sensations. How should we think about dreams? In dreams, we are aware of the unfolding situation in front of us. In dreams, we experience ourselves being part of the action unlike our daydreams or mind-wandering when we are awake. We participate in the experiences of the dream. During dreams we have emotional reactions and experience it as real. However, we would not say it was reality. On the other hand, some philosophers have asked which is more real—when we are dreaming or when we are not.

Research suggests that external events can play an important role in the experience of dreaming. For example, with the advent of COVID-19 worldwide in 2020, the pandemic influenced how individuals remembered their dreams and what they dreamt about (Nielsin, 2020). Overall, people reported more dreams related to the virus such as content about social distancing. One current perspective suggests that dreams present a story which allows the dreamer to explore and evaluate possible scenarios (Zadra & Stickgold, 2021). Thus, dreams allows a number of ideas to be put together in memory.

Since the beginning of recorded history dreams have played a role in the attempt of humans to make meaning of the world and ourselves (Ray, 2010). Dreams have represented the other, the aspects of ourselves and our world that stood outside of human knowledge. As illustrated in a variety of religious texts over the last few thousand years, dreams have been seen to foretell future events as well as allow for communication with the gods. Still, during this period others including the Roman poet Lucretius in 44 BC suggested that dreams are common in all animals. Charles Darwin echoed a similar theme in his The Descent of Man (1874) in which he suggests that all higher animals including birds have dreams.

Within the last 100 years, the understanding of dreams has been brought into a more theoretical perspective within dynamic and analytic psychology and more recently within the context of the neurosciences. Although a topic of heated debate, an initial contribution was Sigmund Freud’s perspective that dreams could be understood within the context of instinctual functioning and neurology outlined in his The Project for a Scientific Psychology (1895).

As articulated in the Project, dreams offered an understanding of previously established networks of neurons and pointed to the manner in which ideas and events had come to be associated with one another in the brain. In this way dreams were reflective of an individual’s psychology during the waking state. Freud also suggested that dreams were reflective of a reduction of logical or I (ego) processes. This in turn would allow for more instinctual processes such as sexuality to be present. Current brain-imaging research suggests that indeed the frontal lobe executive functions are inhibited during the dream state.

Carl Jung, who developed analytic psychology, had a more evolutionary perspective. For him, images in dreams had a particular meaning for a given person. Day-to-day events in our environment could be triggers for bringing forth ideas with a strong emotional component, or complexes as Jung called them. Jung suggested that to understand dreams it was important to examine a long series of dreams over time rather than just a single night’s dream. Dreams in this context reflected patterns in a person’s life. In this sense, what is not in a series of dreams, such as the lack of other people, would be as important as what is the content of the dream. Jung also visited different cultures around the world and reported a similarity of dream material worldwide.

Many view the scientific study of dreams as beginning in 1953 with the discovery by Aserinsky and Kleitman of an association between dreaming and rapid eye movement (REM) sleep. Sleep generally is characterized by four different stages as reflected in the EEG. In contrast to the higher voltage, more patterned EEG activity found in sleep, REM sleep appears to have an EEG pattern more like that of the waking state and is characterized by low voltage random appearing EEG activity. Dreams in the REM state are generally more emotional and vivid than the everyday content of dreams seen in the non-REM state (McCormick & Westbrook, 2013). Both REM and non-REM dreams are associated with decreases in low-frequency EEG activity in the posterior areas of the brain (Siclari et al., 2017).

Waking an individual during REM sleep is more likely than any other sleep stage to result in a dream report. Following the discovery of the association between REM sleep and dreams, a number of labs examined the dream state. The work included a variety of foci, including the nature of the dream itself, factors involved in dream recall, the influence of external factors on dreaming and other factors associated with dreaming. For example, following a natural disaster such as an earthquake, researchers have found an increase in nightmares suggesting that trauma can be related to dreaming. This could also be found during the COVID-19 pandemic in 2020 (Mota et al., 2020). Overall, REM dreams are heavy on emotions and light on logic. The main characteristics of dream processes include emotionally laden sensory processes and images without a sense of individual control.

Figure 6-19 Brain activation during lucid dreaming appears more similar to being awake than during REM sleep.

Less well understood is the so-called lucid dream in which an individual, while dreaming, realizes that she is part of a dream and may even experience control of the dream. Lucid dreams are rare and occur in only 1% or 2% of all reported dreams. Physiological studies show the brains of those experiencing lucid dreaming to be more like an awake state than that seen in normal REM sleep (Voss, Holzmann, Tuin, & Hobson, 2009). In specific, gamma band EEG activity around 40 Hz is associated with the lucid dream experience, especially in the frontal and temporal areas of the brain (Voss et al., 2014). Researchers have asked if inducing gamma band could produce lucid dreams. This is described in the box: Applying Psychological Science—Producing Lucid Dreams with Gamma Activity.

Applying Psychological Science—Producing Lucid Dreams with Gamma Activity

What if you had never experienced a lucid dream, would you want to experience one? That is, would you want to experience thoughts and decisions normally associated with your waking hours, but during sleep? Ursula Voss and her colleagues gave 27 young adults at Göttingen University Medical Center in Germany that opportunity (Voss et al., 2014). Since gamma band EEG activity is associated with lucid dreams, these researchers asked if the opposite was also true. That is, could they induce gamma band activity in someone’s brain that, in turn, would produce lucid dreams?

To induce gamma band EEG activity, they used a technique referred to as transcranial alternating current stimulation (tACS). This is a technique in which battery-produced alternating current is applied to the scalp through two electrodes positioned at the front and back of the brain. The level of the current is such that a person cannot detect its presence. Although lucid dreaming has been associated with 40 Hz EEG activity, these researchers tested seven different frequencies ranging from 2 Hz to 100 Hz. They also included a sham condition in which no alternating current was applied.

The participants spent four nights at the sleep laboratory. The researcher followed the people as they slept. The stimulation was applied for 30 seconds after REM sleep was detected. After the stimulation, the participants were wakened and asked to report their dreams and complete a scale that measured lucid dreaming.

Lucid dreams in terms of the experience of dream insight was experienced during 25 Hz and 40 Hz stimulation. Dream control was experienced with 25 Hz stimulation. Watching one’s own dream (dissociation) was seen at both 25 and 40 Hz. The sham stimulation as well as stimulation at frequencies of 2, 6, 12, 70, and 100 Hz produced no lucid dream experiences. These results are shown in Figure 6-20.

Figure 6-20 Rating of lucid dream measures for stimulation at each frequency. Note: * reflects level of statistical significance.

Source: Voss, Holzmann, Tuin, and Hobson (2009).

One participant described a lucid dream as follows: “I was dreaming about lemon cake. It looked translucent, but then again, it didn’t. It was a bit like in an animated movie, like The Simpsons. And then I started falling and the scenery changed and I was talking to Matthias Schweighöfer (a German actor) and two foreign exchange students. And I was wondering about the actor and they told me, ’Yes, you met him before,’ so then I realized, ’Oops, you are dreaming.’”

This study suggests that 25 and 40 Hz stimulation can produce lucid dream experiences. The researchers further suggest that producing lucid dreams may be a technique for helping those with certain disorders to be able to make active changes to their dreams associated with negative experiences. For example, a person with PTSD might be able to redo a situation during a lucid dream that had previously been of concern to them.

Thought Question: Which of your dreams would you want to redo?

Dreams and Neuroscience

More recently, dream processes have been examined within the context of current neuro-science work. The goal of this research is to determine brain areas involved in dreaming. Also, they want to examine the manner in which dreaming and other cognitive processes (for example, visual imagery) are related. Early speculation suggested that dreams were related to brain-stem functioning especially the pons with its generators for rapid eye movement sleep. However, neuropsychological case studies have shown that damage to the pons does not stop dream reports, whereas damage to the forebrain area does.

Current brain-imaging studies suggest that a variety of brain areas are active during brain states associated with dreaming. These areas include the brain stem, which is responsible for basic arousal; the limbic system, which is highly involved in emotionality; and forebrain areas involved in sensory processing. Areas involved in higher level cognitive processes such as planning and logical thinking showed decreased activation during these dream periods.

Further explorations suggest that during dreaming, cortical pathways between areas involved in emotional processing and those involved in visual processing are active, whereas those between visual processing and higher-level logical thinking are not. In REM sleep, areas related to emotional processing such as the limbic and amygdala regions become activated. Thus, there is emotional processing without logical connections. This may help to explain the nature of dreams in which emotional and non-logical sequencing of imagery are accepted without reflective awareness or control. That is, we have no problem flying through the air or abruptly going from one place on earth to another in our dreams. The nature of dreams has led some researchers to ask if dreaming is like performing jazz music. Indeed, this is what was found. Similar activations in specific brain areas are seen in both dreaming and jazz improvisations (see Kahn & Gover, 2010 for an overview).

One implication that can be drawn from the brain-imaging work is that a variety of processes are involved in the creation of dreams. Such research helps to characterize the nature of the subjective experience of dreaming. However, even today, we often see a replay of the old debate (existing at least since the time of Plato and Aristotle) as to whether dreams reflect our hidden desires or are merely afterthoughts of our behaviors and experiences of the day (McCormick & Westbrook, 2013).

CONCEPT CHECK

1. Since the beginning of recorded history dreams have played a role in the attempt of humans to make meaning of the world and ourselves. What did the following people contribute to our historical understanding of dreams:

a. Lucretius?

b. Charles Darwin?

c. Sigmund Freud?

d. Carl Jung?

e. Aserinsky and Kleitman?

2. What are the characteristics of a lucid dream? What significant results and possible applications came out of the research by Ursula Voss and her colleagues?

3. Brain-imaging studies suggest that a variety of brain areas show changes in activation during brain states associated with dreaming. Specifically, what happens in the different brain areas and how does this help explain the nature of dreams?

Hypnosis and Meditation

Hypnosis is considered by many psychologists to be an altered state of consciousness. Meditation is a technique that focuses one’s consciousness away from the outer world and toward an inner sense of awareness. Although different processes, both hypnosis and meditation have been suggested to influence our consciousness as well as having numerous positive benefits. These positive benefits include reducing anxiety, depression, chronic pain, and stress.

Hypnosis

When we hear the word hypnosis, most of us have an image that comes to our mind. It may be the one from the old movies in which a strange-looking “doctor” moves a watch in front of someone’s eyes. In these old movies, hypnotists can instruct the person to do anything they wish.

Although the old movies were dramatic, they were usually wrong in their presentation of hypnosis. People, for example, will not do anything under hypnosis that they would not do normally. People do report, however, that when experiencing hypnosis, they remain aware of what is being said to them. In this way, they can actively experience what is happening. When told, for example, that their hand is extremely light and will rise like a balloon, they report that they saw it happening by itself. They also report that no effort was involved.

Hypnosis is currently defined by researchers as “an individual’s ability to experience suggested alterations in physiology, sensations, emotions, thoughts, or behavior during hypnosis” (Elkins, Barabasz, Council, & Spiegel, 2015). As can be seen from this definition, changes during the hypnotic experience can take place on different levels. Although the nature of hypnosis is not fully understood, with the advent of EEG and fMRI, researchers have been able to better describe the nature of the process (Ray, 2007; Hoeft et al., 2012; Oakley & Halligan, 2009).

In the 1800s, James Braid introduced the term “hypnosis,” although practices similar to hypnosis had been described since ancient times. The term hypnosis comes from the Greek word for sleep. As such, much of the early work emphasized the nature of the hypnotic experience, especially its relationship to sleep. Ivan Pavlov (1937), for example, saw both hypnosis and sleep as processes that inhibited the brain. Later work began to differentiate hypnosis and sleep.

In the late 1940s, it was reported that EEG recorded during hypnosis was less like sleep and more similar to being awake (Gordon, 1949). Today, it appears that hypnosis allows the different types of information typically integrated in the brain to remain separate. For example, pain such as an electrical shock is composed of two experiences. One is the sensation of the shock and the other is the negative emotional reaction. When told they will not experience pain under hypnosis, individuals still report the sensation but not the negative emotionality. Further, the normal EEG reaction to the pain is not seen in those individuals who are hypnotized, whereas it is seen in those who are not (Ray, Keil, Mikuteit, Bongartz, & Elbert, 2002). Similar results were also seen with visual stimuli (Schmidt, Hecht, Naumann, & Miltner, 2017). Individuals during hypnosis were told to see a virtual wooden board in front of the computer display on which they were doing a counting task. Hypnosis not only reduced performance but also reduced EEG measures associated with attention in comparison to a control group.

Hypnotic Effects

Do you think you could experience hypnosis? It turns out some people experience the state quickly and easily. Those individuals typically enjoy the experience. However, about 25% of all people find it difficult to experience hypnosis. The rest fall somewhere in between. Your ability to experience hypnosis is fairly stable. It has been shown that after 10, 15, and even 25 years, a given person’s ability to experience hypnosis remains constant. Monozygotic twins show a correlation of.5 to.6 in their ability to be hypnotized, whereas dizygotic twins show a correlation of less than.10.

When is hypnosis useful? Hypnosis has now been shown to be an important adjunct to a number of clinical treatments. It has been shown to be useful in controlling pain. The reduction of pain through the use of hypnosis is referred to as hypnotic analgesia. This can either be short-term pain from an operation, for example, or more long-term pain such as that seen in arthritis. Individuals can be taught self-hypnotic techniques, which allow them to reduce the pain on their own.

Hypnosis can also improve results found in traditional psychological treatments such as the treatment of anxiety (Kirsch, Montgomery, & Sapirstein, 1995). Hypnosis can even reduce stress and modify our immune systems in a positive manner (Kiecolt-Glaser, Marcha, Atkinson, & Glaser, 2001). In one study, medical and dental students who were hypnotically susceptible were given relaxation and hypnotic training compared to a control group who were also hypnotically susceptible but did not receive training. Taking a medical school exam is a stressful experience. As such, taking an exam influences the immune system. Those in the hypnosis group did not show the standard immune response to taking major exams. Other studies have shown that hypnosis is useful for helping patients recover more quickly from outpatient surgery.

During hypnosis, what if the person is told not to remember what they are currently doing? They will have difficulty remembering their experiences even after the hypnotic session is over. This is referred to as posthypnotic amnesia. That is, the person does not remember the events that he or she is instructed not to remember. This in turn can be reversed when so instructed.

However, hypnosis cannot improve your memory. Although the movies show a person in the courtroom remembering the license plate number with great certainty, it turns out that the person is often wrong. The thing that hypnosis does is to allow the person to present their answer with great certainty, even if wrong. For this reason, hypnosis is not allowed in court proceedings as a method of gaining accurate information from memory. There are a number of myths concerning hypnosis as described in the box: Myths and Misconceptions—The Myths of Hypnosis.

Myths and Misconceptions—The Myths of Hypnosis

People commonly learn about hypnosis from the movies or ideas that are repeated without scientific evidence. This leaves people believing that you can hypnotize someone and they will do what you tell them. By the way, that is not true. You will not commit crimes or hurt others under hypnosis unless that is what you do in your regular life. Hypnosis researchers at the University of Tennessee, Michael Nash and Grant Beham, have reviewed common myths of hypnosis in terms of what has been found in scientific research (Nash & Beham, 2005). Here is what they found:

Thought Question: Why do you think movies and other media portray hypnosis in a way that does not fit with scientific research?

In terms of brain function, research has suggested that the anterior cingulate (ACC) is involved in the type of executive function that allows one to drive down the street and ignore one set of signs while paying attention to another (Awh & Gehring, 1999). In terms of hypnotic modulation of experience, the anterior cingulate consistently is shown to be an area involved. In a series of polyethylene terephthalate (PET) studies, Rainville and his colleagues have shown that neural activity in the brainstem, thalamus, and ACC contribute to the experience of being hypnotized (Grant & Rainville, 2005; Rainville et al., 2019).

In particular, these authors report absorption-related changes to be seen in the more rostral regions of the ACC. In an earlier hypnotic study involving painful stimuli, Rainville and his colleagues (Rainville et al., 1997) found that activity in the ACC closely paralleled subjective experience, and that it reflected the emotional component (that is, unpleasantness) but not the sensory component of the painful stimuli. Another using high-density EEG showed that hypnosis reduced components of evoked potentials to painful stimulation (Ray, Keil, Mikuteit, Bongaartz, & Elbert, 2002).

In the introduction to neuroscience chapter, you learned that brain networks can be discussed in terms of the default mode network, the executive control network, and the salience network. Using fMRI, these networks were examined in 12 individuals who experienced hypnosis easily and 12 individuals who did not (Hoeft et al., 2012). Those individuals who were easier to hypnotize showed greater brain network connections between the executive network (prefrontal cortex) and the salience network (anterior cingulate) in comparison to low hypnotizable individuals. This suggested to the researchers that the prefrontal areas were able to inhibit the emotional responses through their connection with the anterior cingulate.

From an evolutionary perspective, you might think about whether hypnosis could help individuals adapt to their environment (Ray & Tucker, 2003). Clearly, the ability to modulate pain would be an important aspect of our history as humans. This is particularly true since the development of anesthesia is relatively recent.

Another question you could ask is whether processes similar to hypnosis appear in animals. In 1646, an Austrian monk published a detailed account describing how he had hypnotized a chicken by holding its head on the ground and forcing the animal to fixate on a line drawn away from its beak (Völgyesi, 1966). From that time to the present, there have been a number of stories of how alligators, rabbits, chickens, and other animals could be immobilized, generally by rubbing or stroking the animal, although eye-fatigue through fixation has also been used.

A variety of animal hypnosis studies suggest that in this condition the animals show an analgesia-like response to needle pricks and electric shock. Draper and Klemm (1967), using a learning procedure in rabbits, suggest that the dominant feature of animal hypnosis is a disconnection of overt motor functions without conspicuous inhibition of sensory functions.

Not unlike human hypnosis, immobilization in chickens has been characterized in three stages: (1) vocalizations and continuously open eyes; (2) suppressed vocal behavior and eye flutters; and (3) eyes closed, occasional body twitches, and lack of vocalizations (Rovee & Luciano, 1973). Yes, people have actually studied chickens. Research has shown that once tonic immobility is induced, it remains for anywhere from 10 minutes in chickens to more than 8 hours in lizards. One advantage of remaining still is in terms of survival. That is, predators tend to be sensitive to movement and without it they lose interest and become distracted, allowing the prey to escape. This suggests that animal hypnosis offers a method to tap into the systems related to remaining still.

Pavlov (1927) describes the manner in which inducing hypnosis in animals and humans utilize similar mechanisms and its relation to cortical inhibition. In the second half of the 20th century, a variety of studies examined the concept of animal hypnosis (Gallup, 1974) with some suggesting its value for understanding the hypnotic experience in humans (Draper & Klemm, 1967). However, at this point we do not know if hypnosis in humans and other species share similar underlying mechanisms.

Meditation

Historically, meditation has been a part of religious and spiritual traditions worldwide. Buddhist, Sufi, Zen, and Yogi traditions all have specific forms of meditation, which have been taught from one generation to another. Christian traditions also have used meditative techniques often in the form of prayer and contemplation. The emphasis in each tradition initially focused on how the meditative technique was to be practiced. From the outside each meditative technique appeared to be different. As such, it was difficult to have a single definition of meditation.

However, one can also examine the psychological experiences and internal states related to various forms of meditation. In the 1900s initial examinations of meditative processes sought to link meditation within a psychological perspective. Carl Jung at the beginning of the 1900s sought to see the connections between analytic psychology and meditation. With the influx of Eastern traditions to the United States in the 1960s, a number of psychologists began to research meditation and the meditative state. This has led to its use in treatments for psychological disorders.

In general, meditative techniques can be thought of in terms of three broad approaches (Naranjo & Ornstein, 1971). The first approach is an attempt to reduce awareness as normally experienced. One technique that uses this approach is to constantly repeat a mantra or single word while ignoring everything else. Other techniques have the person sit and pay attention to only their breathing. The second approach is more of an expressive experience as might be seen in free dancing. Freud’s use of free association in which a person says whatever comes to his or her mind is not unlike these techniques. The third approach is located between these two approaches. That is, awareness of all activity is allowed without the attempt to reduce, modify, or react to what is being experienced. Such techniques were practiced in Theravada Buddhism and have come to be called mindfulness in current-day psychology.

Mindfulness has gained popularity and has been empirically shown to be effective in reducing stress and treating a number of psychological problems (Shapiro & Carlson, 2017). Mindfulness involves an increased focused purposeful awareness of the present moment. The idea is to relate to one’s thoughts and experiences in an open, nonjudgmental, and accepting manner (Kabat-Zinn, 1990). The basic technique is to observe thoughts without reacting to them in the present. That is, you allow your thoughts and feelings to come without reacting to them. This increases sensitivity to important features of the environment and one’s internal reactions. This in turn leads to better self-management and awareness as an alternative to ruminating about the past or worrying about the future. This reduces self-criticism.

Nonjudgmental observing allows for a reduction in stress, reduction in reactivity, and more time for interaction with others and the world. Also, feelings of compassion for another person become possible. This broadens attention and alternatives. Meta-analysis performed by Hofmann and his colleagues examined 39 studies of mindfulness (Hofmann, Sawyer, Witt, & Oh, 2010). He found significant reductions in anxiety and depression following mindfulness techniques. Paul Grossman and his colleagues examined 20 studies and found overall positive changes following mindfulness approaches (Grossman, Niemann, Schmidt, &, Walach, 2004; see also Hofmann, Grossman, & Hinton, 2011). Empirical evidence using mindfulness techniques has shown positive change with a number of disorders including anxiety, depression, chronic pain, and stress.

Overall, meditation has been shown to increase well-being. In relation to this, psychologists have asked if there is plasticity, that is, are brain changes associated with meditation. The answer appears to be yes. In one study, the increase in well-being was correlated with an increase in gray matter in areas of the brainstem (Singleton, Hölzel, Vangel, Brach, Carmody, & Lazar, 2014). Another study randomly assigned individuals to a six-week longitudinal trial of mindfulness meditation or to a control group that read about wellness (Allen et al., 2012). Although six weeks is a short period, those who learned mindfulness meditation were better able to inhibit negative emotionality. This was associated with changed brain areas associated with emotionality. Other studies have shown changes in EEG activity of long-term meditators (Richard, Lutz, & Davidson, 2014).

CONCEPT CHECK

1. What is the technical definition of hypnosis?

2. What individual differences are found in experiencing hypnosis?

3. What are some examples in which hypnosis has been used as part of a clinical treatment?

Are these statements about hypnosis true or false?

a. Relaxation is an important feature of hypnosis.

b. Hypnotized people cannot be led to do acts that conflict with their values.

c. Hypnosis is something to do with a sleeplike state.

d. Ability to imagine vividly is related to hypnotizability.

4. In general, meditative techniques can be thought of in terms of three broad approaches. Briefly describe each of these approaches.

5. What is mindfulness, and what are some of the benefits it can bring to the individual?

Psychoactive Substances

Throughout our evolutionary history, we discovered that there are some plants referred to as psychoactive substances, which change our brain in a manner that influences our consciousness, including thoughts and feelings. Betel nut has been chewed for its nicotine-like effects for at least 13,000 years in Timor, an island north of Australia (Saah, 2005). Cocaine is naturally available in coca leaves, and morphine is available from poppy plants. Archaeological evidence suggests that Peruvian foraging societies were chewing coca leaves some 8,000 years ago. Actual poppy seeds were recovered from a 4,500-year-old settlement in Switzerland. Other evidence shows that opium was available in the neolithic, copper, and bronze ages. We as humans thus discovered naturally occurring psychoactive substances.

Besides naturally occurring psychoactive substances, humans also learned to ferment and distill plants. With the beginning of farming about 10,000 years ago, humans discovered how to make alcoholic beverages such as beer and wine, although it may have happened even earlier. Evidence from Iran, the former soviet republic of Georgia, and China suggest humans were making wine 8,000 years ago, that is 2,000 years before we began to write (Estreicher, 2017; McGovern et al., 2017). Depending on the region, humans have used barley, wheat, grapes, rice, honey, and a variety of fruits to make alcoholic drinks. In fact, there is some suggestion that we made beer before we made bread (Hayden, Canuel, & Shanse, 2013).

Addiction

As noted, seeking psychoactive substances is part of human history. As humans, we like using these substances in a variety of situations. In comparison to liking a substance, wanting and seeking it uses a different pathway in the brain, which is related to addiction. Many researchers make a distinction between drug use, drug abuse such as binge drinking, and addiction.

In terms of addiction, there is a common pattern (see Figure 6-21). Initially, the positive experience of taking the drug leads to a compulsion to seek and take a given substance. It can be experienced as a rush or sense of well-being. This period of intoxication is also associated with impaired cognitive abilities. This is followed by a craving in which the individual loses control of the ability to limit intake of the drug. For example, even when the blood alcohol of a person with an alcohol addiction is high, he or she still drinks more. The next condition is the emergence of a negative emotional state when the substance is unavailable or access to it is limited. What once gave a positive feeling now does little. In fact, the person needs the drug to feel normal. There is a paradox in that by this last stage, people who are addicted want their psychoactive substance more than they enjoy it.

Figure 6-21 Pattern of addiction.

There is no one answer as to what causes addiction (see Volkow & Li, 2005 for an overview). One factor is related to timing of first use. With alcohol, those who began using alcohol before the age of 15 are four times more likely to become addicted in their lifetime in comparison to those who begin at age 20 or older. Our brain reorganizes itself beginning in adolescence. Current research suggests that drugs affect adolescents in a different manner than they do adults. Adolescence is clearly a time that the brain is reestablishing connections and networks and is sensitive to the use of addictive substances. During adolescence are brain changes that by the time you are in your 20s have led to the development of better impulse control and other executive functioning in the frontal lobes.

Another factor related to addiction is genetics. There is a strong genetic factor in that 40 to 60% of vulnerability to addiction can be attributed to genetic factors. These genetic factors and their relationship with the environment can be seen in the manner in which different drugs show different levels of reinforcing factors and influence metabolism. That is, some drugs are more addictive than others. Also, individuals show different sensitivities to particular drugs and thus some people can become addicted to some drugs more quickly than they can to other drugs. In addition, genetics can make one more addicted to a particular drug more quickly than other individuals with different genetic makeup.

Environmental factors such as stress and/or low socioeconomic level are also associated with greater drug use, which can lead to addiction. With adolescents, peer pressure can play an important role in deciding whether or not to try new types of drugs. Adolescence is also a time when individuals take risks and try new things. The environments in which both adults and adolescents live play a crucial role. This is compounded by research that shows that drugs may disrupt networks of the brain involved in making decisions. Drugs not only influence what people seek for rewards but also the ability to inhibit these desires.

With the advent of brain imaging and other neuroscience techniques, research has suggested that there is a common underlying process to a variety of disorders that share the desire to engage in certain activities. These disorders include drug addiction, binge eating, pathological gambling, and sexual addiction (see Goodman, 2007 for an overview).

Can drugs actually change your brain? The answer is yes. Drugs do change your brain. In fact, for someone addicted to a particular drug, just seeing the paraphernalia associated with it can produce physiological changes before the drug is actually ingested. It does not matter if it is heroin or whiskey. This works in a manner similar to how all learning changes your brain, although drug addiction seems to last longer than simple learning (see Nestler & Malenka, 2004 for an overview). Addiction can last for weeks, months, or even years after the last ingestion of the drug. This sets up the possibility of relapse since your body has a difficult time forgetting the effects of the drug.

On a neuroscience level, studies show the rewarding effect of drugs is their ability to increase dopamine (see Hyman, Malenka, & Nestler, 2006; Volkow, Wang, Fowler, & Tomasi, 2012; and Wise & Robble, 2020 for overviews). One important pathway begins in the ventral tegmental area (VTA), which is located near the base of the brain. Although a small population of neurons, the VTA has an impressive influence on reward and aversive behaviors (Morales & Margolis, 2017).

These pathways connect with the nucleus accumbens, prefrontal cortex, dorsal striatum, and the amygdala. Dopamine (DA) is released in these structures. Dopamine was initially thought to be the neurobiological correlate of reward or pleasure. However, more recent research has clarified dopamine’s function. It is suggested that the presence of dopamine signals to the person that something good is about to happen. Thus, dopa-mine is not so much associated with pleasure as with the expectation of pleasure. In this sense, it is involved in motivating individuals to engage in certain behaviors that make them feel good. In this way, the presence of dopamine predicts a reward. In the process, the events associated with the reward become part of the person’s memory. Thus, all of the events associated with using a drug come together to remind you of the pleasant experience. Overall, many drugs of addiction increase activity in the VTA and the nucleus accumbens.

Molecular mechanisms of many drugs leave excessive dopamine available in the brain (see Figure 6-22). This can work by different mechanisms. Cocaine either blocks dopamine uptake in the synapse or increases dopamine released by the terminals of VTA cells, which increases dopamine signaling in the nucleus accumbens. Alcohol and opiates such as opium and heroin enhance dopamine release by quieting neurons that would otherwise inhibit dopamine-secreting neurons. Nicotine induces VTA cells to release dopamine into the nucleus accumbens. Now, let us look at these and other psychoactive substances.

Figure 6-22 The manner in which different drugs affect the brain.

CONCEPT CHECK

1. Throughout our evolutionary history, humans have ingested psychoactive substances. Give a brief timeline of what we know about that history including dates, locations, and substances.

2. What can animal studies tell us about the power of psychoactive substances on the individual?

3. What are the steps in the pattern of addiction, and what drives the process from one step to the next?

4. There is no one answer to what causes addiction, but what are three important factors that should be considered?

5. How can drugs change your brain? What is the role of dopamine in the effect of psychoactive substances?

Major Psychoactive Substances

Traditionally, psychoactive substances are discussed in terms of their effects on the central nervous system. Three broad categories are depressants, stimulants, and hallucinogens. Depressants such as alcohol and barbiturates reduce the activity of the central nervous system. This reduction of activity can be seen overall as when a person falls asleep after drinking alcohol or more localized as when reduction in frontal lobe activity reduces the inhibitions experienced by the person. Stimulants, on the other hand, increase the activity of the central nervous system. Common stimulants include amphetamines, caffeine, nicotine, cocaine, and opiates such as morphine. The class of psychoactive drugs that has the most influence on the central nervous system is hallucinogens (Schartner, Carhart-Harris, Barrett, Seth, & Muthukumaraswamy, 2017). Although hallucinogens such as LSD, mescaline, and psilocybin have strong effects on the central nervous system, they tend to be the least addictive. Also, animals will not work for these drugs as they do for cocaine.

Alcohol

Alcohol has been available to humans for a large part of our history. For at least 10,000 years, humans have made wine, beer, and other drinks through a process of fermentation. During fermentation, yeast breaks down sugar found in grains, such as barley, and fruits, such as grapes, into ethanol (alcohol) and carbon dioxide. Once carbon dioxide is removed, the ethanol and water remain in the form of wine or beer. Higher alcohol drinks such as gin, vodka, rum, and whiskey are further heated after fermentation in the process of distilling to remove the water. The percentage of alcohol in a substance is measured in terms of proof, which is twice the percentage of alcohol (e.g., 20% alcohol equals 40 proof). The amount of alcohol in beer and wine can vary and is usually listed on the label. Researchers consider 12 oz. of beer, 5 oz. of wine, and 1.5 oz. of liquor to contain ½ oz. of pure alcohol.

In many cultures around the world, alcohol is used for celebrations such as weddings and parties. Part of the reason for alcohol’s use in celebrations is its effect on our central nervous system. In most humans, the initial experience of alcohol intake includes pleasant subjective experiences that may lead to increased social interactions. This is partly related to the effects of alcohol on such neurotransmitters as serotonin, endorphins, and dopamine. Alcohol will also decrease inhibition by reducing the effects of the GABA system, which is associated with anxiety. However, if the amount of alcohol intake is increased, it will increase the effects of GABA, which can lead to sedation. This is why alcohol is generally listed as a depressant. As an addictive substance, it can also lead to social, legal, and medical problems.

Unlike most of the other foods you eat, alcohol is absorbed directly in the bloodstream without digestion. When you drink a beer or other alcoholic beverage, it goes to your stomach. In your stomach, only a small amount of alcohol is absorbed, as most alcohol is absorbed in the small intestine. However, if there is food in your stomach, it is absorbed more slowly. If the alcoholic drink contains food substances, as does beer, it is also absorbed more slowly. On the other hand, drinks with carbon dioxide such as champagne or a mixed drink with a carbonated beverage are moved from the stomach to the small intestine more rapidly where most alcohol is absorbed into the bloodstream. The experience of feeling the effects of alcohol takes place when alcohol is carried through the bloodstream to the brain. As a result, champagne will give you the experience of alcohol faster than beer since it gets to your brain faster.

Cannabis

Cannabis is a plant species also referred to as marijuana. Cannabis resin is referred to as hashish. The cannabis plant can easily be cultivated both indoors and outdoors. For this reason, it is grown and used throughout the world. In fact, cannabis has been used worldwide for at least 4,000 years for its psychoactive effects. During this period, it has been seen as an important medical compound and as a religious and recreational substance. The physician Galen in AD 200 wrote that it was customary to give cannabis to guests to promote hilarity and enjoyment (Stuart, 2004).

Cannabis has a history of use in China, India, Europe, and the Middle East. It came to the United States during the 1900s. In the United States during the 1960s, it became a recreational drug of choice for many individuals. Since the 1960s, there have been changing views as to whether the drug should be decriminalized for all adults, made available strictly for medical purposes such as pain relief, or banned completely. At this point about half of the states in the US have legalized some form of marijuana use. The United Nations estimates that 4% of the population of the world uses cannabis. The United States is one of the larger users of cannabis in the world.

Individuals who use cannabis report a wide variety of experiences. Small doses produce enjoyable positive feelings associated with a feeling of being “high.” This can include states in which time stands still. The person often may see his or her own ideas as exceptionally creative and important. Cannabis can also influence appetite with short-term users reporting increasing hunger or “munchies.” Larger doses can produce negative feelings such as anxiety and paranoia. Hallucinations and persecutory delusions have also been reported. Most of these experiences are short-lived but in some cases can last longer. More long-term use is also associated with cognitive impairment in executive functions (Crean, Crane, & Mason, 2011).

The main psychoactive ingredient in cannabis is THC (Δ9-tetrahydrocannabinol) and was first described in the 1960s. THC particularly affects receptors in the hippocampus, the cerebellum, the basal ganglia, and the neocortex. THC affects receptors in the brain that also release GABA, an inhibitory neurotransmitter related to anxiety. The brain also produces its own substances that are similar to cannabis. These are referred to as cannabinoids. These cannabinoids appear to be related to reducing the negative experiences associated with troubling past experiences, which is similar to the effects of cannabis.

Opioids

Opioids are substances derived from the opium poppy that have been used for thousands of years to control pain and bring on euphoric feelings. In fact, poppy seeds have been found at Neanderthal burial sites from 30,000 years ago (see Stuart, 2004, for an overview). About 3400 BC, Sumerians referred to the opium poppy as the “joy plant.” From there, it spread throughout the world during the next 2,000 years. Opium was available in the street markets of ancient Rome. In 1860, Britain imported some 220,000 pounds of opium for medical and recreational use.

The more common opioids are heroin, opium, morphine, methadone, and oxycodone (trade names of OxyContin, Percocet). Variations of these drugs are currently used in medical settings primarily for reduction of pain following operations or pain experienced with some types of cancer. Opioids became popular in the United States after the Civil War for their ability to control pain; however, some individuals given these drugs became addicted to them. Abuse took the form of the opium den of the last century in which the drug was smoked. With the availability of the hypodermic needle, it was injected directly into the bloodstream. Before the early 1900s, opioids were available legally in the United States. In 2017, the United States Government declared opioid misuse and addiction related to pain relief a national emergency.

Cocaine

Cocaine comes from the naturally occurring coca plant. For thousands of years, individuals have chewed the leaves of the coca plant for its psychoactive experiences. It is largely grown in South America. Cocaine was even used to make Coca-Cola in about 1900. About this time, Sigmund Freud tried the drug and found it to be very pleasant. Its effects include a mental alertness including feelings of euphoria, energy, and a desire to talk. It also heightens the experience of sensory processes such as sound, touch, and sight, as well as producing physiological effects such as increased heart rate and blood pressure. The introduction of cocaine interferes with natural brain processes, resulting in an increase of dopamine. This increased dopamine is, in turn, involved in the effects experienced with cocaine.

Cocaine has been administered by smoking, snorting through the nose, or injecting directly into the bloodstream. The form of cocaine that is smoked is referred to as crack. Crack refers to the sounds made when the white cocaine crystals are heated to turn it into a form that can be smoked. Taking it through the nose results in a slower “high” than intravenously, which shows effects in 4 to 6 minutes. Cocaine has a shorter effect life in comparison with other drugs. That is, most of its effect is completed in 15 to 40 minutes. Like alcohol, individuals may use cocaine in binges.

Amphetamines

Like cocaine, amphetamines are stimulants that result in positive feelings, a burst of energy, and alertness. However, unlike cocaine, it is a substance produced in the laboratory rather than found in nature. Amphetamine was first developed in the 1880s. It was not until the 1930s that it was introduced as a medicine in the form of an inhaler for the treatment of a stopped-up nose. Also during this time it was introduced in the form of pills with the name Benzedrine, which were called “bennies” (see Iversen, 2006; Koob, Kandel, & Volkow, 2008, for overviews).

During the 1930s and 1940s, amphetamines were prescribed by health professionals for the treatment of more than 30 disorders, including epilepsy, Parkinson’s disease, schizophrenia, migraine, and even behavioral problems in children. They were also prescribed to reduce addictions to other substances such as alcohol, morphine, and tobacco. During World War II, amphetamines were given to solders as pep pills to give them an edge in combat. The common ones were Benzedrine, Dexedrine, and Methedrine, the last one being methamphetamine. Although there are chemical differences in amphetamine and methamphetamine, they both function as stimulants.

As people experienced the stimulant effects, they began to abuse the use of amphetamines. In the 1950s, long-distance truck drivers would use them to drive farther. After they were publicized for use as a recreational drug from Hollywood to New York, the US government began to pay attention. Amphetamines were also making their way into teenage parties. In 1959, the US Food and Drug Administration (FDA) required that amphetamines only be available by prescription.

The main reason people take amphetamines is that they believe they enhance performance and help them feel good. The common experience is euphoria, increased vigilance, and hyperactivity. The reactions from amphetamines are also similar to other stimulant drugs. They are easy to take in the form of a pill, which can be conveniently purchased one pill at a time on the illegal market. Amphetamines are not considered to be harmful by many individuals. Taking these drugs through intravenous injection or smoking increases the feeling of a rush.

In their 2011 global assessment, the United Nations suggests that amphetamine-type drugs are the second most widely used drugs throughout the world (United Nations Office on Drugs and Crime, 2011). The first is cannabis. This makes amphetamine use greater than heroin or cocaine worldwide. Amphetamine-like drugs do not require the cultivation of plants. Instead, they can be manufactured almost anywhere without an advanced knowledge of chemistry.

As with other stimulant drugs, amphetamines affect the dopamine system to produce the initial euphoric experience. In addition to the short-term experience, there are also less positive long-term effects (see Marshall & O’Dell, 2012, for an overview). These long-term effects, especially from methamphetamine, create brain changes in three areas. The first is the development of compulsive patterns of use. The second produces negative brain changes consistent with brain injury. And third, methamphetamine produces changes in the individual’s cognitive functioning.

People who use methamphetamine show problems with motor activities such as skill movements or perceptual speed. They also experience problems in the ability to shift attention. Finally, research also suggests memory, attention, and decision-making problems. These types of problems make it difficult for individuals to view their addiction objectively as well as be able to engage in therapy requiring cognitive responses. Methamphetamine also has a devastating effect on physical appearance, which can be seen in the before and after mug shots of the Oregon Multnomah County Detention Center (www.facesofmeth.us/main.htm).

Hallucinogens

Hallucinogens are drugs that alter perceptual experiences (see Nichols, 2004, for an overview). The word hallucinate actually comes from the Latin meaning to wander in the mind. Some of these drugs occur in nature and have been used by various cultures for thousands of years. These include mescaline, which comes from the peyote cactus and psilocybin, which comes from a variety of mushroom. Historians suggest they were often part of religious ceremonies to give experiences not part of everyday life. Other hallucinogens such as LSD (d-lysergic acid diethylamide) begin with a grain fungus, ergot. Although the fungus is naturally occurring, LSD was first made in the laboratory. Other laboratory-made drugs include MDMA (3,4 Methylenedioxymethamphetamine), commonly known as ecstasy, MDA (3,4 Methylenedioxyamphetamine), sometimes referred to as the love drug, and PCP (Phencyclidine), also known as angel dust.

Figure 6-23 Devastating effects of long-term methamphetamine use on physical appearance.

Hallucinogens are also called psychedelics and are able to alter perception, mood, and cognitive processes in often unpredictable ways (Hollister, 1984). These can be described in terms of somatic, perceptual, and psychic symptoms. Somatic symptoms include dizziness, weakness, tremors, nausea, drowsiness, and blurred vision. Perceptual symptoms include altered shapes and colors, difficulty in focusing on objects, sharpened sense of hearing, and at times synesthesia. Psychic symptoms include alterations in mood (happy, sad, or irritable at varying times), tension, distorted time sense, difficulty in expressing thoughts, depersonalization, dreamlike feelings, and visual hallucinations.

After about 50 years of ignoring psychedelic drugs for their possible use in the treatment of mental illness, new research has begun (Vollenweider & Preller, 2020). Although illegal in the United States, hallucinogens have been used in treating some mental disorders worldwide (Begola & Schillerstrom, 2019). Brain-imaging techniques are beginning to show the effects of psychedelics. At this point it is unclear which hallucinogens should be used in treatment such as LSD and which may be dangerous such as PCP. As with any process, abuse and dependence are possible, although the pattern is not the same. Drugs that are addictive typically affect the dopamine system and the experience of reward. It is also possible to train animals to self-administer addictive drugs, but this is not the case with hallucinogens. They also appear to lack the toxic effects on human organs seen in alcohol or tobacco, for example. However, not all experiences with hallucinogens are positive. A so-called bad trip can include extreme anxiety and fearful psychotic-like experiences.

Hallucinogens do not directly affect dopamine neurotransmission as do alcohol, cannabis, tobacco, and cocaine. Structurally, the chemical makeup of hallucinogens is similar to the neurotransmitter serotonin. In fact, early theories suggested that hallucinogens produced their effects by increasing serotonin in specific brain areas. It is now known that hallucinogens bind to the 5-HT serotonin receptor.

Drugs Found in the Brain

In the last century, a number of scientists began to wonder why our bodies seek various types of drugs. What became apparent was that our brains contain receptors that are sensitive to the actual drugs of addiction (see Bolles & Fanselow, 1982 for a historical overview). In particular, there are receptors in the brain that are sensitive to opiates such as morphine. What researchers then discovered is that our brains made a substance that is actually like morphine. These substances came to be called endorphins. Endorphin is a combination of the word for internally produced—endogenous—and the ending syllable of morphine. The particular endorphin of interest to psychologists is beta-endorphin or β-endorphin.

Research since that time has shown that β-endorphin (beta-endorphin) has an analgesia effect similar to drugs like morphine. Further, if a substance such as naloxone that blocks the effect of opiates is administered, the analgesia effects are reduced. Current research has shown that β-endorphin is also released during our body’s response to stress (Charmandari, Tsigos, & Chrousos, 2005). This is seen by some as the explanation of how soldiers are able to fight or athletes to play under pain. The basis of positive experiences in running or eating have also been linked to β-endorphins.

CONCEPT CHECK

1. What are the three broad categories of psychoactive substances and what are their primary effects on the human central nervous system?

2. Describe the process of alcohol absorption to explain what causes the differences in how alcohol is experienced.

3. What is the primary psychoactive ingredient in cannabis? What are its impacts on an individual’s body and brain?

4. What are some common opioids? What is it about opioids that makes them sought after as medicines as well as substances to abuse?

5. Describe the range of mental, sensory, and physiological effects related to cocaine?

6. What are some of the factors that promote the use and abuse of amphetamines?

7. What are three long-term negative impacts of methamphetamines?

8. Hallucinogens are not addictive, but in what other ways can they cause impairments to the individual using them?

9. What are endorphins, and how are they related to why our bodies seek various types of drugs?

Summary

Learning Objective 1: Discuss the different levels of consciousness, including attention and awareness.

Psychologists define consciousness as being aware and knowing that you are involved in a particular event. You listen to certain music because you like the feelings it gives you. You eat certain foods for the feeling of comfort and the memories associated with such meals. Reading a book or watching videos can also change our consciousness. You may even seek to reduce your level of consciousness as when you take a nap. At times, we may perform yoga or meditation as a way to experience our internal processes.

Experiences such as spacing out while driving suggest that there must be different processes that come together to give us the experience of consciousness. We have different systems of consciousness and awareness for living life and making decisions. That is, whether at a party or driving, we are able to monitor other aspects of the environment without being aware of it. Research shows sudden EEG changes in the brain to be associated with conscious awareness. That is, during conscious awareness, more areas of the brain are communicating with one another. Further, there is no single brain area related to consciousness; rather it is the result of the interactions among a number of neural networks in our brain.

In terms of attention, we can be aware of something. This is the basic level where we have sensations and create perceptions. Another level of awareness important for humans is referred to as meta-awareness. That is, we can be aware of our awareness. As humans, we not only have awareness of our awareness (meta-awareness) but also cognition about cognition or metacognition.

Levels of consciousness can be discussed in terms of (1) coma, (2) vegetative state, and (3) wakefulness and awareness. From this perspective, consciousness can be described in terms of wakefulness and awareness. Between coma and normal consciousness, there is a continuum in which a person varies in terms of awareness and the ability to communicate. A common procedure that is designed to change the level of a person’s consciousness is the use of anesthesia. Combining the ability to control anesthesia with current brain-imaging techniques has opened up new ways to study levels of consciousness.

When we look at an object, we become conscious of what it is. However, it generally takes about half a second before our brain gives us the experience of being aware of what is there. When we shift our attention to something else, the original object leaves our consciousness. In this manner, attention and consciousness are closely related in our everyday language. This chapter considered two different long-term conditions in which a person is able to process information without being aware of it—blindsight and being a split-brain individual.

Learning Objective 2: Describe what happens when we sleep and dream.

We are just beginning to understand the various processes that go on during sleep. Sleep serves a number of functions. Our experience tells us that sleep is a strong drive and related to restoring our bodies in terms of energy and alertness. Evolutionary perspectives tell us that sleep may be protective and may keep the organism out of danger.

At some point during the night, the person’s eyes—although closed—would move quickly. This is referred to as rapid eye movement or REM sleep. After a REM period, the person goes through another series of sleep cycles. These 90-minute cycles continue throughout the night, although the deepest sleep is experienced in the early cycles. Human adults sleep for about 8 hours every 24 hours. This is a daily or circadian rhythm, which takes about 12 years to develop in humans. Across species including humans and other animals, there is a sleep/wake cycle related to earth’s day/night cycle. With access to the sun, there is a stable sleep/wake cycle. This circadian or 24-hour rhythm has been shown to be fairly stable even in species such as those that live in the Arctic with continuous daylight in part of the year.

Since sleep represents a special state of consciousness, some scientists suggest that it can give us a window into understanding consciousness. From this standpoint, the three processes of (1) wakefulness, (2) REM sleep, and (3) non-REM sleep represent three different states of consciousness. Each of these states involves different brain and other physiological processes. Over the past 100 years, studies of sleep with humans and animals have painted a consistent picture of the physiological processes involved in sleep and wakefulness. Brain-imaging techniques such as fMRI show the manner in which cortical networks are involved in sleep. (1) First, it is clear that the brain continues to be active in sleep even without external stimulation or self-control of our thoughts. (2) Second, sleep is controlled by bottom-up processes involving the brain stem and the hypothalamus. (3) Third, during sleep some of the same networks such as those involved in memory, arousal, and consciousness are active. In fact, different memory systems are seen to be active during different types of sleep. (4) Fourth, during sleep the frontal areas of the brain are not connected to other areas of the default network. The loss of connection to the frontal areas is one reason our dreams can be irrational or even chaotic. Without logic, you can dream anything you want.

Complaints concerning sleep are second only to those concerning pain in terms of physician visits. In the medical and psychological literature, more than 100 different sleep disorders have been described. However, most of these can be discussed in terms of four broad categories. These four are (1) insomnia, (2) hypersomnia, (3) circadian rhythm disorders, and (4) parasomnias.

Dreams are experienced during sleep and reflect mainly involuntary images, ideas, feelings, and sensations. In dreams, we (1) are aware of the unfolding situation in front of us; (2) experience ourselves being part of the action unlike our daydreams or mind-wandering when we are awake; (3) participate in the experiences of the dream; and (4) have emotional reactions and experience it as real although we would not say it was reality.

Learning Objective 3: Describe the techniques of hypnosis and meditation.

Although different processes, both hypnosis and meditation have been suggested to influence our consciousness as well as having numerous positive benefits. These positive benefits include reducing anxiety, depression, chronic pain, and stress.

Hypnosis is defined by researchers as “an individual’s ability to experience suggested alterations in physiology, sensations, emotions, thoughts, or behavior during hypnosis.” From this definition, changes during the hypnotic experience can take place on different levels. Although the nature of hypnosis is not fully understood, with the advent of EEG and fMRI researchers have been able to better describe the nature of the process. It appears that hypnosis allows the different types of information typically integrated in the brain to remain separate. For example, pain such as an electrical shock is composed of two experiences—the sensation of the shock and the negative emotional reaction. When told they will not experience pain under hypnosis, individuals still report the sensation but not the negative emotionality. Hypnosis has now been shown to be an important adjunct to a number of clinical treatments. It has been shown to be useful in controlling pain, in the treatment of anxiety, in reducing stress, and positively modifying our immune systems.

Meditation is a technique that focuses one’s consciousness away from the outer world and towards an inner sense of awareness. Historically, meditation has been a part of religious and spiritual traditions worldwide. In general, meditative techniques can be thought of in terms of three broad approaches: (1) an attempt to reduce awareness as normally experienced; (2) an approach that is more of an expressive experience as might be seen in free dancing; and (3) an approach located between these two—awareness of all activity is allowed without the attempt to reduce, modify, or react to what is being experienced. This last approach has come to be called mindfulness in current-day psychology. Mindfulness involves an increased focused purposeful awareness of the present moment. The idea is to relate to one’s thoughts and experiences in an open, nonjudgmental, and accepting manner. Nonjudgmental observing allows for a reduction in stress, reduction in reactivity, more time for interaction with others and the world, a greater possibility of feelings of compassion for another person, and a broadening of attention and alternatives. Empirical evidence using mindfulness techniques has shown positive change with a number of disorders including anxiety, depression, chronic pain, and stress. Overall, meditation has been shown to increase well-being. In addition, there are brain changes associated with meditation.

Learning Objective 4: Discuss the three broad categories of psychoactive substances: depressants, stimulants, and hallucinogens.

Three broad categories of psychoactive substances are depressants, stimulants, and hallucinogens. Depressants such as alcohol and barbiturates reduce the activity of the central nervous system. This reduction of activity can be seen overall as when a person falls asleep after drinking alcohol or more localized as when reduction in frontal lobe activity reduces the inhibitions experienced by the person. Stimulants, on the other hand, increase the activity of the central nervous system. Common stimulants include amphetamines, caffeine, nicotine, cocaine, and opiates such as morphine. The class of psychoactive drugs that has the most influence on the central nervous system is hallucinogens. Although hallucinogens such as LSD, mescaline, and psilocybin have strong effects on the central nervous system, they tend to be the least addictive

In the United States, our attitude toward drug use has changed drastically over the past 200 years. Overall, drugs are rewarding to our body and give us experiences we seek, but drug use is a complex problem for a society to protect its citizens, especially those whose brains are still developing, from psychoactive substances that can be addictive, reduce productivity, and put the user and others at risk.

There is a common pattern to addiction: (1) craving characterized by drug expectation and attention bias; (2) intoxication and impaired self-awareness; (3) bingeing and the loss of control; and (4) withdrawal characterized by amotivation and anhedonia. There is no one answer as to what causes addiction, but a number of factors have been found to be involved. (1) One factor is related to timing of first use. (2) Another factor related to addiction is genetics. (3) Some drugs are more addictive than others. (4) Individuals show different sensitivities to particular drugs. (5) Environmental factors such as stress and/or low socioeconomic level are also associated with greater drug use, which can lead to addiction.

In the last century, a number of scientists began to wonder why our bodies seek various types of drugs. What became apparent was that our brains contain receptors that are sensitive to the actual drugs of addiction, in particular, to opiates such as morphine. Researchers discovered that our brains make a substance that is actually like morphine—substances that came to be called endorphins. The particular endorphin of interest to psychologists is beta-endorphin or β-endorphin, which has an analgesia effect similar to drugs like morphine and is also released during our body’s response to stress.

Study Resources

Review Questions

1. Many people throughout history have taken different approaches to define consciousness. How would you weave what you’ve learned about awareness, attention, sleep, dreams, hypnosis, meditation, and psychoactive substances into a definition of consciousness?

2. This chapter begins by asking a question: “How would you determine whether the messages you were getting on your computer were from a human or a machine? Are there distinct factors that would help you determine human consciousness from machine responses?” Now it’s your turn—what factors would you include in your response?

3. Plot out your cycle of sleep patterns throughout the night from the time you go to bed until you wake up in the morning—what happens at each stage?

4. Some philosophers have asked, which is more real—when we are dreaming or when we are not. Given everything you have read in this chapter as well as in the previous chapter on sensation and perception, how would you now answer this question?

5. The author states, “Today, it appears that hypnosis allows the different types of information typically integrated in the brain to remain separate.” What types of information is he talking about, and what is the effect of separating them?

6. Looking back at the table on the myths of hypnosis, which three myths were most surprising to you? How has your view of hypnosis changed from examining these myths?

7. Historically, meditation has been a part of religious and spiritual traditions worldwide. Having read this chapter, do you think there is a place for meditative practice in the secular world? What evidence would you use to support your answer?

8. Your middle school heard you were taking a course in Introductory Psychology and has asked you to develop a lesson to present to middle school students—in terms they would pay attention to—including what you think they need to know about psycho-active substances, addiction, and naturally occurring drugs in the brain. What points would you include?

9. A number of the psychoactive substances covered in this chapter provide benefits as medicines—for example, opioids, cannabis, and amphetamines. On the other hand, it is clear that individuals can abuse or become addicted to these substances, which can lead to negative consequences. What principles would you use in developing a policy surrounding their use, including who could use them, what types of illnesses they should be used for, and who would regulate that use?

For Further Reading

✵ Dehaene, S. (2014). Consciousness and the Brain. New York: Viking.

✵ Feinberg, T., & Mallatt, J. (2016). The Ancient Origins of Consciousness. Cambridge, MA: MIT Press.

✵ Leschziner, G. (2019). The Nocturnal Brain: Nightmares, Neuroscience, and the Secret World of Sleep. New York: St. Martin’s Press.

✵ Mendelson, W. (2017). The Science of Sleep: What It Is, How It Works, and Why It Matters. Chicago, IL: University of Chicago Press.

✵ Ramachandran, V. (1998). Phantoms in the Brain. New York: William Morrow and Company.

✵ Shapiro, S., & Carlson, L. (2017). The Art and Science of Mindfulness, 2nd ed. Washington, DC: American Psychological Association.

✵ Zeman, A. (2002). Consciousness: A User’s Guide. New Haven, CT: Yale University Press.

Web Resources

✵ Blindsight—https://www.youtube.com/watch?v=4x0HXC59Huw

✵ Invisible gorilla—http://www.theinvisiblegorilla.com/gorilla_experiment.html

✵ Randy without sleep—http://www.esquire.com/lifestyle/a2527/esq0804-aug-awake/

✵ Additional Randy--http://www.gelfmagazine.com/archives/sleeping_in.php

✵ Mike Birbiglia—http://www.npr.org/templates/story/story.php?storyId=130644070 and https://www.cnn.com/2012/10/02/health/sleepwalking-rem-behavior-disorder/index.html

✵ Long-term meth use—www.facesofmeth.us/main.htm

Key Terms and Concepts

addiction

alcohol

amphetamines

anesthesia

attention

cannabis

circadian

circadian rhythm disorders

cocaine

consciousness

corpus callosum

dopamine

dreams

endorphin

hallucinogens

hemispheric specialization

hypersomnia

insomnia

levels of consciousness

meditation

meta-awareness

metacognition

opioids

parasomnias

psychoactive substances

rapid eye movement or REM sleep

sleep patterns

split-brain