Paper review - Social cognition & the human brain.
Paper reviewed by Melanie Darwood as part of the requirement for Cognitive Anthropology module, BSc Cognitive Science.
Paper Title: Social Cognition & the Human Brain,
Written by Ralph Adolphs, from Trends in Cognitive Sciences.
Humans are extremely social animals, but the neural foundations of social cognition & behaviour aren’t well understood. Studies have highlighted structures that have a key role in guiding social behaviour, including the amygdale, ventromedial frontal cortices & right somatosensory-related cortex.
They appear to act as a go-between between perceptual representations & retrieval of knowledge.
Social cognition refers to processes that subserve behaviour in response to conspecifics (that is, other individuals of the same species) particularly those concerned with the varied & flexible social behaviours found in primates. It is suggested that humans’ unique cognitive skills can be traced to development in an environment in which there was a reward for social skills. To support this there is correlation between group size & the ratio of neo-cortex volume to the rest of the brain among numerous primate species, also for other mammals that have a complex social structure. Another suggestion is that brain size correlates with other factors, such as tool use, longevity or dietary foraging strategy, but brain size could be a partial result of primates having an intricate ecological position regarding social structure. This hypothesis is called the Machiavellian Intelligence hypothesis or the Social Brain hypothesis, & suggests that the sophisticated primate’s social structure, with its characteristics of cooperativity & deception led to an advantage for larger brains.
This is a preview of the whole essay
This paper looks at the neural foundations of social cognition using lesion studies & functional imaging in the context of what is already known about social cognition, from anthropological, comparative & developmental studies. There are various studies that suggest there are specialised systems within the brain for processing socially relevant information.
In the 1930’s Kluver & Bucy found that when they inflicted large lesions on monkey brains across the amygdala, temporal neo-cortex & neighbouring areas the monkeys could perceive & respond to objects but their behaviour was inappropriate, compared to the normal emotional significance that would have been produced. More selective lesions produced more subtle impairments.
In humans, the view that the frontal lobes contribute to behaviour first came about on the basis of an accident. A railroad worker, Phineas Gage, had a metal rod shot through his head from an accidental explosion. He suffered a large bilateral lesion of his frontal lobe, including the ventro-medial pre-frontal cortices. Before the accident he had been industrious, reliable, polite, socially skilled, he became uncaring, rude, & socially inappropriate. The reason for his personality change was unidentified until more recently when it could be understood with reference to similar patients. Others with comparable damage demonstrated similar impaired abilities regardless of normal results on neuropsychological tests.
Damage to certain areas of the brain results in impairments that are extremely specific & this gives support to theory of innately specified modules for processing specific categories of knowledge. Research on subjects with autism & on those with Williams’s syndrome, whose sufferers display symptoms opposite to those with autism, gives support to the theory of functional modularity.
Studies have used functional neuroimaging in comparative studies of those with damage to the amygdala; these have given evidence for its role in recognising emotions from facial expressions, especially those seen as negative, such as fear. Also, other studies have shown that subjects with severe damage to this area tend to be unusually friendly towards others, lacking normal methods for identifying those who should be avoided, similar changes in the behaviour of other primates with more selective damage have been seen, but the human patients don’t appear to be as impaired in their social behaviour as monkey with similar brain damage.
The frontal lobes are critical in linking perceptual representations of stimuli with representations of their social & emotional significance. Damage to the ventromedial pre-frontal cortex leads to an inability to organise & plan future activity, a reduced ability to react to punishment & inappropriate social manners, also to a lack of concern & empathy for others. One task involved gambling, subjects were required to make decisions based on incomplete info, using probabilistic reasoning, and particular choices would pay off better than others, so after time they could make choices based on a feeling that the choice would be the better one. Subjects with damage to the ventro medial prefrontal cortex fail this because they are unable to represent a choice bias in the form of an emotional hunch; they also have no subjective feeling regarding their choices or any anticipatory autonomic changes.
The role of the VM frontal cortex in reasoning has also been investigated, using the Wason selection task. Those with bilateral damage to the VM prefrontal cortex were impaired in normal reasoning about social & familiar scenarios, but not so when reasoning about abstract material.
How we represent the minds of others is also discussed briefly, the idea put forward being that our ability to estimate others emotions, dispositions, beliefs, desire could depend on our ability to empathise with them & also on how we represent ourselves to ourselves.
Social cognition uses a large collection of abilities, some quite specific, others more general. Some emotions, such as jealousy or guilt, only seem sensible in social contexts & possibly developed to subserve particular roles in communication. Others use systems that subserve emotional processing in general, systems that enable us to generate models of others through simulation, all part of a large network of structures that contribute to reasoning, inferencing & language.
Certainly animals & humans are different in their social skills, but also it is obvious that we share some mechanisms with other animals.
Quote: The challenge for the future will be to offer a more precise account of the interplay between all these different processes as a function of the detailed specification of the performance demands required by a given experimental task, or by a given situation in real life.