Temporal dynamics of affect in the brain: Evidence from human imaging and animal models

Emotions are time-varying internal states that promote survival in the face of dynamic environments and shifting
homeostatic needs. Research in non-human organisms has recently afforded specific insights into the neural
mechanisms that support the emergence, persistence, and decay of affective states. Concurrently, a separate
affective neuroscience literature has begun to dissect the neural bases of affective dynamics in humans. However,
the circuit-level mechanisms identified in animals lack a clear mapping to the human neuroscience literature. As
a result, critical questions pertaining to the neural bases of affective dynamics in humans remain unanswered. To
address these shortcomings, the present review integrates findings from humans and non-human organisms to
highlight the neural mechanisms that govern the temporal features of emotional states. Using the theory of affective
chronometry as an organizing framework, we describe the specific neural mechanisms and modulatory
factors that arbitrate the rise-time, intensity, and duration of emotional states.