The role of the mirror neuron system in social cognition
Cognition and development
Mirror neurons are nerves in the brain that are active when specific actions are performed or observed in others, allowing observers to experience the action as if it was their own. Mirror neurons may therefore allow individuals to share in the feelings and thoughts of others by empathising with and imitating others, therefore permitting them to have a ToM. The action of mirror neurons is such that when individuals experience an emotion, for instance disgust, or observe an expression of disgust on another’s face, the same mirror neurons are activated. This permits the observer and the person being observed to have direct experiential understanding of each other. The mirror neurons for disgust ’fire up’ in both individuals, creating a sensation within the mind of the feeling associated with disgust, allowing immediate empathy with what the other person is experiencing. Research has suggested that mirror neurons also permit the understanding of others’ intentions as well as their behaviour. Mirror neurons are found in brain areas involved with social cognition and therefore may be the biological mechanism by which the comprehension of our own and the mental states of others occurs. Defective mirror neuron systems may explain conditions such as autism.
Fig 11.5 Do mirror neurons allow humans to directly experience other people’s feelings and thoughts?
Dapretto et al. (2006) assessed mirror neuron ability in autistic and normally developed children. 80 facial expressions representing 5 emotions of anger, fear, happiness, neutrality and sadness were randomly presented for 2 seconds each to 10 high-functioning autistic children and 10 normally functioning children aged 10—14 years. fMRI scans were performed as participants either observed or imitated the faces presented. Symptom severity of autism was measured through the Autism Diagnostic Interview-Revised Scale A. Both groups were able to observe and imitate the facial expressions. However, the autistic children showed no mirror neuron activity in the frontal gyrus brain area and a correlation was found between degree of autism and mirror neuron activity in other brain areas associated with mirror neuron activity. This suggests differences exist in the neural pathways used by typically developing and autistic children and that there is a biological basis to social cognition and the development of autism.
• Stuss et al. (2001) reported that individuals with damage to their frontal lobes often had an inability to empathise with and read other people’s intentions and were easy to deceive, which suggests damage to the mirror neuron system and emphasises its importance to normal human social cognition.
• Gallese (2001) used fMRI scanning to find that the anterior cingulate cortex and inferior frontal cortex are active when individuals experience emotion or observe another person experiencing the same emotion, supporting the idea of mirror neuron-type activity occurring in humans.
• Iacoboni et al. (2005) recorded the activity of single neurons in the inferior parietal lobule, to find that different neurons fired off when a monkey grasped an object to eat it as opposed to grasping an object to place it, even though both required similar hand movements. This suggests mirror neurons allow intentions of others’ behaviour to also be understood.
Studies using fMRI scans have found evidence of mirror neuron systems in humans in the same brain areas as macaques (though there seems to be a wider network of brain areas in humans, especially the somatosensory cortex), which suggests the findings of animal studies into mirror neurons are relevant to humans.
Research into mirror neurons has indicated a possible biological explanation for autism and greater understanding may pave the way for developing methods of counteracting the social deficits associated with the disorder.
Heyes (2012) argues that even if mirror neurons do exist, it is not established yet whether they actually have evolved purely to permit the understanding of actions through the process of natural selection, or whether they are merely a biological by-product of social interaction between individuals.
Kosonogov (2012) argues that if individuals can understand the motivation behind other people’s actions by mirror neurons firing off when observing a goal-directed action or a pantomime of a goal-directed action (such as someone acting in a film), how is it possible to know when an action is real and not a pantomime of an action (for example, telling the difference between someone really crying and someone pretending to cry)?
Research into mirror neurons may not just allow us a greater understanding of autism and how it develops but may also lead to effective treatments and therapies to counteract the disorder, especially in terms of how sufferers struggle to empathise with and understand the mental state of others.