This article reviews the modern literature on two key aspects of the central circuitry of emotion: the prefrontal cortex (PFC) and the amygdala. There are several different functional divisions of the PFC, including the dorsolateral, ventromedial, and orbital sectors. Each of these regions plays some role in affective processing that shares the feature of representing affect in the absence of immediate rewards and punishments as well as in different aspects of emotional regulation. The amygdala appears to be crucial for the learning of new stimulus-threat contingencies and also appears to be important in the expression of cue-specific fear. Individual differences in both tonic activation and phasic reactivity in this circuit play an important role in governing different aspects of anxiety. Emphasis is placed on affective chronometry, or the time course of emotional responding, as a key attribute of individual differences in propensity for anxiety that is regulated by this circuitry.