“Basis functions for complex social decisions in dorsomedial frontal cortex”, published in Nature on 12 March, tackled the question: How does our brain keep track of complex social situations with multiple people?
The researchers’ findings suggest “basis functions” are the key mechanism for making complex social group interactions tractable for the brain. Basis functions describe the fundamental building blocks that underlie a specific problem. Like LEGO pieces, you can combine them in different ways to build anything from a small house to a complex castle. What could these building blocks be in social groups? Wittmann and colleagues reasoned that the building blocks themselves could specify a part of a pattern – an aspect of how a group of people might work together or against each other – that is common to many situations. It would specify the relationships between individuals rather than information about the individuals themselves.
The study found brain signals related to basis functions for social interactions. The signals were found in the medial prefrontal cortex, a region critical for making decisions and thinking about the social world.
These findings suggest that the fundamental rules by which the brain stores information about complex situations are similar across visual, motor and social domains. This may bring us a step further towards understanding human social behaviour from a biological perspective, but it also opens many new questions about how basis functions are constructed and changed.