Excitotoxic lesions of the gustatory thalamus spare simultaneous contrast effects but eliminate anticipatory negative contrast: evidence against a memory deficit.
Using consummately contrast procedures and the same taste stimuli (0.15% saccharin and 1.0 M sucrose), the authors tested the hypothesis that lesions of the gustatory thalamus disrupt gustatory memory in 2 experiments. In Experiment 1, irrespective of the duration of the intersolution interval (0 s, 30 s, 1 min, 2 min, 4 min, 8 min), thalamic lesions had no influence on the expression of simultaneous contrast effects. In Experiment 2, thalamic lesions abolished anticipatory negative contrast at the 0-s intersolution interval. These results provide no support for the experimental hypothesis. Rather, the data seem best interpreted as a lesion-induced disruption of the comparison mechanism responsible for anticipatory negative contrast. By this analysis, different comparison mechanisms underlie simultaneous and anticipatory contrast effects.
Reilly
Steve
S
Department of Psychology, University of Illinois at Chicago, Chicago, IL 60607, USA. sreilly@uic.edu
Bornovalova
Marina
M
Trifunovic
Radmila
R
D000339:Affect; D000818:Animals; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000503:physiopathology; D003259:Consummatory Behavior / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000008:administration & dosage; D013649:Taste / Q000502:physiology*; D013788:Thalamus / Q000473:pathology / Q000503:physiopathology*
D012439:Saccharin