Our brains use basic 'building blocks' of information to keep track of how people interact, enabling us to navigate complex social interactions, finds a new study led by University College London (UCL) researchers.
For the study, published in Nature, the researchers scanned the brains of participants who were playing a simple game involving a teammate and two opponents, to see how their brains were able to keep track of information about the group of players.
The scientists found that rather than keeping track of the performance of each individual player, specific parts of the participants' brains would react to specific patterns of interaction, or 'building blocks' of information that could be combined to understand what was going on.
Lead author Dr Marco Wittmann (UCL Psychology & Language Sciences and Max Planck UCL Centre for Computational Psychiatry and Ageing Research) said: "Humans are social creatures that are capable of keeping track of highly complex and fluid social dynamics, requiring a massive amount of brain power to remember not only individual people but also the various relationships between them.
"In order to keep up with a group social interaction in real time, our brains must be using heuristics – mental shortcuts that help people make decisions quickly – to compress and simplify the wealth of information involved, with a system that minimises complexity while still allowing flexibility and detail.
"In this research, we found that our brains appear to use a set of basic 'building blocks' that represent fundamental aspects of social interactions, enabling us to quickly figure out new and complex social situations."
For the study, the team of scientists from UCL and the University of Oxford used functional magnetic resonance imaging (fMRI) to record the brain activity of 88 participants who were playing a simple game. While in the scanner, the study participants were given a series of information about how they, a partner, and their opponents were faring in a game, and needed to keep track of the information in order to answer a question comparing performances of different players.
Dr Wittmann explained: "We were interested to see whether our brains would use an 'agent-centric' frame of reference where specific parts of the brain keep track of each player's performance, or a 'sequential' frame of reference tracking the information in the order it was received. We found that people actually do both, but our brains are able to simplify all of this information into bite-sized chunks."
The scientists were able to pinpoint specific patterns of activity in the brain that represented a few specific 'building blocks', each representing a pattern of interaction between the players.
For example, one building block kept information about how well a participant and their partner were doing relative to the other team. A bigger difference in performance between the two teams corresponded to an increase in brain activity related to this building block. These specific patterns of activity were found in the prefrontal cortex, which is involved in decision-making and social behaviour.
The researchers say these fundamental building blocks appear to represent patterns of interaction that are common to many different situations.
Dr Wittmann said: "As we develop social skills in life, our brains are likely learning specific interaction patterns that we come across again and again. These patterns may become hard-wired into our brains as building blocks that get assembled and recombined to construct our understanding of any social setting."
