Scott A. Bailey, Ph.D.
COMPANY: Texas Lutheran University
Advisor: Dr. Stephen Kiefer
Functional contributions of the rat gustatory cortex: Learned avoidance and aversiveness to illness-paired tastes.
Four experiments compared the acquisition of orofacial responding to illness-paired tastes by control rats and rats that lacked gustatory cortex (GC). GC Rats developed aversive taste reactivity to illness-paired, 1 min intraoral infusions of sweet (Experiment 1) and bitter (Experiment 2) tastes, but failed to transfer learning to home cage consumption testing. In Experiment 3, GC rats did not develop aversive behavioral responding over three, 10 min acquisition trials in a box that permitted observation of activity during voluntary consumption. GC rats from Experiment 4 (10 min illness-paired infusions) reflected palatability shifts as efficiently and completely as control rats, and transferred learning to home cage extinction testing. However, the transfer effect was transient for GC rats as they increased consumption significantly on Days 2, 3, and 4 (in comparison to Day 1) of extinction testing. Longer exposures of illness-paired tastes presented intraorally improve the likelihood that GC rats will learn to develop trans-situational aversive responding.
Ph.D., Psychology, Kansas State University, 1996