The objective of the proposed research is to identify and characterize patterns of physiologic and behavioral response which are reliably expressed together under specific conditions of organism-environmental interaction. Eventually, knowledge of such behavioral/physiologic linkages can be applied in identifying basic mechanisms whereby the role of behavioral factors in pathogenesis of cardiovascular disease is mediated. The central nervous system appears organized to produce patterns of responses, rather than isolated responses of single variables. One well-known example of such a pattern is that known as the "defense reaction", consisting of increased somatomotor activity and cardiac output, with shunting of blood away from skin and viscera to skeletal muscles. This pattern is elicited in circumstances requiring either emergency motor activity or mental work. Recent work leads to the hypothesis of another, qualitatively different pattern of behavioral/physiologic response under circumstances requiring the organism to engage in sensory intake behavior. Here, the physiologic response pattern appears to be one of decreased somatomotor activity and cardiac output, with an active vasoconstriction in skeletal muscle as well as skin and viscera. We shall test this hypothesis by comparing physiologic and neurohumoral response patterns in a large sample of young males under conditions of mental work versus conditions requiring sensory intake behavior. The reliability and generalizability of the sensory intake pattern will be tested, along with the influence of individual differences in cognitive style. Preliminary assessment of sensory intake and mental work/defense patterns in cardiovascular disease pathogenesis will include evaluation of the relation of coronary-prone (Type A) behavior pattern and presence of hypertension and coronary disease to patterns of behavioral/physiologic response under mental work and sensory intake conditions.