Comparative connectomics of the primate social brain

Area of Science:

• Comparative neurobiology
• Evolutionary neuroscience
• Systems neuroscience

Background:

• Social interaction is a proposed driver of human intelligence evolution.
• The neurobiological underpinnings and evolutionary trajectory of social behavior across primates are not well understood.
• Comparative connectomics is an emerging field utilizing neuroimaging in humans and non-human primates (NHPs).

Purpose of the Study:

• To review the macroscale neural mechanisms of social behaviors from a systems neuroscience perspective.
• To explore the relationship between brain organization and social behavior across the primate lineage.
• To identify potential homologies in neural systems supporting social cognition between humans and NHPs.

Main Methods:

• Analysis of the association between cortical neuron number and primate social group size.
• Application of species-harmonized functional magnetic resonance imaging (fMRI) to compare brain function.
• Review of recent developments in neurobiology related to social perception, joint attention, and personality.

Main Results:

• A positive correlation exists between the number of cortical neurons and primate social group size, suggesting a link to information-processing capacity.
• Functional organization similarities were observed in mirror neuron system and default-mode networks between macaques and humans.
• These findings suggest potential homologous neural substrates for social cognition.

Conclusions:

• Comparative neuroimaging, including Human Connectome Project (HCP)-style studies, offers insights into the neural basis of social behavior.
• The study highlights the potential evolutionary foundations of human social behavior through cross-species comparisons.
• Future multi-modal investigations are crucial for advancing our understanding of social cognition's evolution.