Neural Substrates of Social Behavior in the Primate Brain

Abstract

Many brain structures are known for carrying out more than one function. Among these structures the amygdala emerged particularly versatile, as it has been implicated in cognitive processes that range from sensory-perceptual, to decision-making, and to overt behaviors accompanied by autonomic responses. While no single functional definition can capture its role in the brain, the diversity of functions linked to the amygdala is likely reflected in the response properties of its component neurons. The goal of this study was to determine the extent to which single neurons in the amygdala can exhibit multiple types of stimulus-selectivity and/or task-related responses in the context of a complex task. The task involved learning and decision making based on stimulus-reward associations where the choices were presented as multiple simultaneously playing videos with social and non-social content. Here we report that amygdala neurons are tuned to multiple stimulus and task dimensions. Furthermore a disproportionate number of neurons responded to all of the features examined. This demonstration of multi-dimensional selectivity in the amygdala provides evidence that the amygdala is not composed exclusively of discrete circuits, but rather of common overlapping populations that encode multiple types of information.