Motivation and Emotion

Abstract

How the brain encodes motivation and emotion is both a compelling and a frustrating issue for many neuroscientists. This is in no small part because both of these mental phenomena are ill-defined psychological constructs that cannot be directly studied. Instead, we are forced to make inferences about them from observations of behavior in experimental circumstances or from verbal reports of “feelings” by human subjects. Unfortunately, the same behavior can be executed for any number of reasons, and aside from the inherent ambiguity of language, verbal reports, ironically, are subject to emotions and hidden motives. Even despite these impediments, progress has been made on the basis of experimental work and careful observations in clinical cases of brain damage. As a result, several circuits have been implicated as contributors to either motivation, emotion, or both. Some neuroscientists find it useful to lump such circuits together into a hypotheti- cal computational unit called the limbic system.