| Abstract: | 12 male hooded Long-Evans rats were divided into groups for either a control operation or a lesion of the fimbria-fornix. Ss were trained in several versions of a barpress, spatial alternation task. In free operant conditions across 5 experiments, Ss with fimbria-fornix lesions showed adequate alternation performance when the bars were relatively separated by placement either at the ends of an alley or at the ends of the arms of a T-maze, but they were impaired when bars were adjacent. Lesioned Ss also failed to alternate after interpolation of either baffles or a 10-sec delay in the stem, both of which resulted in intervening turning responses before each choice. Results are accounted for by a failure to discriminate memories of relevant, discrete events from those of similar, intervening events. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
