Nina Louise Tarner, Ph.D.
TITLE: Assistant Professor
COMPANY: Sacred Heart University
Advisor: Dr. Jerome Frieman
Evidence for extinction and spontaneous recovery of a conditioned flavor preference
It is well established that flavor and food preferences can be affected by experience, specifically Pavlovian conditioning. However, past research has been unable to demonstrate extinction of flavor preferences produced by Pavlovian conditioning. This dissertation provides the first evidence for the extinction and spontaneous recovery of a conditioned flavor preference.
In Experiment 1, rats were conditioned to prefer one flavor to another by pairing that flavor (CS+) with sucrose and another flavor (CS-) with saccharin. These rats were then randomly assigned to one of four groups after conditioning: One of the experimental groups was given access to their CS+ flavor without sucrose (extinction) and the other experimental group was given access to both the CS+ and CS- flavor, but on alternating days. One of the two control groups was given access to their CS- flavor without the saccharin and the other control group was given access to water. During a two-bottle preference test given after the extinction sessions, the subjects in the two experimental groups consumed more of the CS- flavor than the CS+ flavor. The subjects in the two control groups continued to show a preference for the CS+ flavor. Thus, the subjects in the two experimental groups exhibited extinction of a conditioned flavor preference.
Experiment 2 was designed to replicate the results in Experiment 1 and then to demonstrate spontaneous recovery of the extinguished flavor preference. In Experiment 2, conditioning occurred in the same manner as in Experiment 1. During extinction training, the rats were assigned to one of three groups: The subjects in the experimental group were given access to their CS+ flavor, without the sucrose (extinction). One of the two control groups was given access to their CS- flavor without the saccharin and the other control group was given access to water. During a two-bottle preference test after extinction, the subjects in the experimental group exhibited extinction by decreasing their intake of the CS+ flavor and increasing their intake of the CS- flavor. A spontaneous recovery test was administered 7, 14, and 21 days after the extinction test. The preference for the CS+ flavor returned on all three tests, thus demonstrating spontaneous recovery for an extinguished flavor preference.
These data have implications for our understanding of the mechanisms underlying the conditioning of flavor preferences.
Ph.D., Psychology, Kansas State University, 2001