Affective Neuroscience History and Major Concepts

Abstract

Abstract Our emotional feelings reflect our ability to subjectively experience certain states of the nervous system. Although conscious feeling states are universally accepted as major distinguishing characteristics of human emotions, in animal research the issue of whether other organisms feel emotions is little more than aconceptual embarrassment. Such states remain difficult-some claim impossible-to study empirically. Since we cannot directly measure the internal experiences of others, whether animal or human, the study of emotional states must be indirect and based on empirically guided theoretical inferences. Because of such difficulties, there are presently no direct metrics by which we can unambiguously quantify changes in emotional states in any living creature. All objective bodily measures, from facial expressions to autonomic changes, are only vague approximations of the underlying neural dynamics-like ghostly tracks in the bubble chamber detectors of particle physics. Indeed, all integrative psychological processes arise from the interplay of brain ciruits that can be monitored, at present, only dimly and indirectly. Obviously, a careful study of behavioral actions is the most direct way to monitor emotions. However, many investigators who study behavior have argued that emotions, especially animal emotions, are illusory concepts outside the realm of scientific inquiry. As I will seek to demonstrate, that viewpoint is incorrect. Although much of behavioral control is elaborated by unconscious brain processes, both animals and humans do have similar affective feelings that are important contributors to their future behavioral tendencies. Unfortunately, the nature of human and animal emotions cannot be understood without brain research. Fortunately, a psycho-neurological analysis of animal emotions (via a careful study of how animal brains control certain behaviors) makes it possible to conceptualize the basic underlying nature of human emotions with some precision, thereby providing new insights into the functional organization of all mammalian brains. A strategy to achieve such a cross-species synthesis will be outlined here. It is based largely on the existence of many psychoneural homologies-the fact that the intrinsic nature of basic emotional systems has been remarkably well conserved during the course of mammalian evolution. Although there is a great deal of diversity in the detailed expressions of these systems across species, the conserved features allow us to finally understand some of the fundamental sources of human nature by studying the animal brain.