The role of arousal in hedonic evaluations

Autonomic correlates of alimentary conditioned and unconditioned reactions in the dog

Analysis of changes in cardiac action and the secretion of saliva during unconditioned alimentary activity in 6 dogs revealed that the beginning of food consumption was accompanied by acceleration of the heart rate (HR) without an increase in salivation. In the course of eating, the heart rate decelerated and salivation increased. Alimentary conditioned stimuli of excitatory (CS+) and inhibitory (CS-) character always produced cardiac acceleration, which in the case of CS+ was accompanied by secretion of saliva. The findings indicate that during food consumption activation of the autonomic system depends upon the contents of motivational processes. In the course of an alimentary act the parasympathetic withdrawal (heart rate acceleration and decrease in salivation) seems to reflect the drive component of the act, while the following parasympathetic activation (heart rate deceleration and increase in salivation) is probably associated with an hedonic component of the consummatory reaction. In our study alimentary conditioned stimuli evoked both drive and hedonic components of alimentary motivation.