Object interactions in juvenile rats (Rattus norvegicus): Effects of different experiential histories.

Examined the spontaneous ways in which an individual rat gathers information about its environment and the extent to which this information-gathering strategy is modified by experience. 30 male rats of the Berkeley S? strain were placed at weaning in enriched, group-housed, or impoverished conditions. After 30 days, they were placed individually in a dimly illuminated arena with several objects and videotaped for 10-min periods on 2 successive days. Analysis of the videotaped records showed no significant differences among the groups in locomotion, investigation of the arena, defecation, grooming, or total amount of object contact, but it showed significant differences in behaviors used during interactions with objects. Ss from the enriched condition showed significantly more diversity of behavior related to those objects that were small enough to be moved, without intergroup differences in amount of object contact. These experience-dependent changes in strategies for exploration may have widespread functional consequences. The procedure for videotape analysis presented here may be useful in studying many problems of animal behavior. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)