Preweanling and adult rats treat conditioned light-tone combinations differently |
| |
| Authors: | Philipp J Kraemer Norman E Spear |
| |
| Institution: | 1. Department of Psychology, University of Kentucky, 40506, Lexington, KY
2. Department of Psychology, State University of New York at Binghamton, 13901, Binghamton, NY
|
| |
| Abstract: | Ontogenetic differences in processing light-tone compounds were discovered in preweanling (17-day-old) and adult (60–80-day-old) rats. Suppression of general activity was used as an index of the magnitude of conditioned fear following a single training session in which a CS+ was paired with mild footshock. In Experiment 1, rats were trained on discriminations in which the CS? consisted of a light and the CS+ was either a tone alone (simple discrimination) or a light-tone compound (simultaneous feature-positive discrimination). Adults and preweanlings given each type of discrimination were then tested for fear of the CS? and a target stimulus (tone alone or light-tone compound). Adults in all groups displayed greater fear of the target than of the CS?. Preweanlings, however, discriminated the CS? from the target only when the target was the same as the original CS+. Experiment 2 revealed that age-related differences in conventional stimulus generalization is not a likely explanation for the pattern of results found in Experiment 1. Experiment 3 revealed age-related differences in expressed fear of a serial feature-positive discrimination; adults, but not preweanlings, showed greater fear of the compound than of the CS?. Alternative interpretations of the results from these experiments are discussed, and the general conclusion is that adults appear more inclined to process elements of a compound stimulus selectively, whereas preweanlings seem more likely to process the compound unselectively, with roughly equivalent processing of each element. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
