Do interoceptive signals influence higher cognitive processes? We found that the physiological state of the body (which can be manipulated by drugs with peripherally-restricted action) predicts decisions on approach-avoidance conflict tasks. We are expanding these questions into the social domain to determine whether social behavior can be altered by interoceptive afferents.

We are monitoring the eye movements of monkeys while they view dyadic, aggressive-appeasing interaction videos to determine whether interoceptive manipulations alter their scanpaths and their ability to learn a social hierarchy through transitive inference.

In the absence of explicit indicators, social status can be inferred from observing the signals exchanged between individuals. We simulated social interactions between macaques by juxtaposing videos of aggressive (dominant) and appeasing (subordinate) displays and found that neurons in the amygdala signal – through a latent variable -  the status of the dominant or the subordinate animal.

We also examined the local field potentials associated with socially meaningful eye movements in the amygdala and hippocampus of macaques while they watched videos of dominant-subordinate interactions. The timing, frequency, and status-specificity of these power transients reveal a differential contribution of the amygdala and hippocampus to the visual exploration of social scenes.

Adolescence in primates is a protracted period of remodeling in the brain, body, and multiple aspects of the socio-emotional behavior required for successful integration of an individual into society. We have longitudinally documented changes in the physical, hormonal, and behavioral maturation of adolescent macaques in parallel with structural changes in the brain.

While age alone is a poor predictor of adolescent development, increased plasma levels of estradiol predict both increased prosocial behavior and structural differentiation of the amygdalo-prefrontal connections as measured by non-invasive neuroimaging techniques.