ABSTRACT
Affective behaviors are evoked when environmental circumstances pose a threat or challenge to an organism. These integrated somatic and visceral response patterns to emotionally significant stimuli allow an organism to adapt to its environment during stressful situations. Our research program has focused on the central nervous system (CNS) mechanisms that underlie the expression of integrated response patterns to environmental stressors and to the sensory mechanisms that mediate learned emotional responses to these environmental challenges. Several working hypothesizes serve as heuristic guides for our studies. One hypothesis is that the autonomic components of learned affective behaviors are mediated by the neuronal circuitry that subserves hard-wired, unlearned responses to emotional stressors, such as the defense reaction. The autonomic components of the defense reaction serve to prepare the organism for “fight or flight.” Fight or flight behaviors are not appropriate for the psychosocial stressors that humans face, and although humans do not typically engage in these behaviors, the response patterns of the autonomic nervous system associated with them are still evoked by psychosocial stressors. As a case in point, the cardiovascular responses elicited during the preparation for a stressful speech task are the same ones evoked during the defense reaction, although they clearly exceed the metabolic demands of the task. In general, the autonomic responses elicited to psychosocial stressors are the same ones evoked during unlearned responses to emotional stressors, although they are not always the ones associated with the defense reaction. The observation that these responses exceed the metabolic demands of the task has led a number of investigators to suggest that this is a factor in the etiology of stress-related diseases.
