Abstract

As an organism interacts with the world, how good or bad things are at the moment - the value of the organism's current state - is an important parameter that is likely to be encoded in the brain.  As the environment changes and new stimuli appear, estimates of state value must be continuously updated to support appropriate responses and learning.  We examined how the brain mediates this process by recording neural activity in primate amygdala during a conditioning procedure.  The presentation of different stimuli induced state transitions; these stimuli included primary rewards and punishments, newly learned reinforcement-predictive stimuli, and familiar stimuli long associated with reinforcement. Amygdala neural responses tracked the value of the current state.  These signals could underlie how the amygdala helps coordinate and influences cognitive, emotional, and behavioral responses depending upon one’s state.