Conover K L, Shizgal P
Department of Psychology, Concordia University, Montreal, Quebec, Canada.
Behav Neurosci. 1994 Jun;108(3):559-72. doi: 10.1037//0735-7044.108.3.559.
The effects of postingestive feedback on the value of intraoral sucrose and lateral hypothalamic (LH) stimulation were compared. Rats chose between a fixed LH stimulation train or a compound reward composed of the same stimulation train and an oral infusion of 1 M sucrose. The rats preferred the compound reward when postingestive feedback was reduced by opening a gastric cannula. However, when the cannula was closed, the compound was preferred only at the beginning of each session, and preference declined or reversed as consumption continued. A second experiment showed that the reduction in preference caused by closing the gastric cannula was not due to a punishing effect of the gastrointestinal load. This study suggests that postingestive signals modulate gustatory reward at a stage of processing before gustatory and brain stimulation rewards are combined.
