Social network size affects neural circuits in macaques

Area of Science:

• Neuroscience
• Primatology
• Social Cognition

Background:

• Previous research suggests a correlation between social network size and brain structure variation.
• The causal relationship between social network size and brain structure changes remains unestablished.

Purpose of the Study:

• To investigate whether social network size causally influences brain structure and function.
• To explore the neural underpinnings of social complexity in non-human primates.

Main Methods:

• Neuroimaging was performed on 23 monkeys housed in social groups of varying sizes.
• Brain structure (gray matter) and functional activity coupling were analyzed.
• Dominance rank within social networks was also assessed.

Main Results:

• Living in larger groups led to increased gray matter in the mid-superior temporal sulcus and rostral prefrontal cortex.
• Enhanced functional activity coupling was observed between frontal and temporal cortical areas in larger groups.
• Gray matter differences in these regions correlated with individual dominance rank.

Conclusions:

• Social network size is a causal factor in altering brain structure and function.
• These neural changes may have implications for social success and dominance.
• The study provides evidence for the neurobiological impact of social environment on the brain.