Rats with damage to the hippocampal-formation are impaired on the transverse-patterning problem but not on elemental discriminations.
We assessed the effects of hippocampal-formation (HF) damage on the rat's ability to learn two sets of concurrent visual discriminations. Each set included three problems. One set, called the transverse-patterning problem, was constructed so that each choice stimulus was ambiguous; sometimes it was the correct (+) and sometimes it was the incorrect (-) choice as follows: A+ vs. B-, B+ vs. C-, and C+ vs. A-. It could not be solved unless rats used configural associations. The stimuli were not ambiguous in the second, elemental problem set, A+ vs. B-, C+ vs. D-, and E+ vs. F-. Rats could solve this set without the use of configural associations. Rats with HF damage solved the set of elemental problems, but their performance on the transverse-patterning problem was impaired. These results support Sutherland and Rudy's (1989) theory that the hippocampal formation is critical for the acquisition of configural associations.
Alvarado
M C
MC
Department of Psychology, University of Colorado, Boulder 80309, USA.
Rudy
J W
JW
D000818:Animals; D001245:Association Learning / Q000502:physiology; D001288:Attention / Q000502:physiology; D002755:Choice Behavior / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D004924:Escape Reaction / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011340:Problem Solving / Q000502:physiology*; D051381:Rats; D012153:Retention, Psychology / Q000502:physiology*