LIMBIC LESIONS AND ERROR REDUCTION

Trained 3 monkeys with hippocampal lesions, 4 with ablations of the amygdala, and 4 sham-operated Ss on a series of visual discrimination problems in which there was always 1 rewarded stimulus while the number of unrewarded cues varied between 1, 2, and 4. Ss with amygdaloid lesions did not reliably differ from the sham operates on any test and no differences between any of the 3 groups approached reliability when only 1 negative cue was used. On tests involving multiple negative cues, however, the group with hippocampal lesions required significantly more sessions to reach criterion than did either of the other 2 groups. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.