Some effects of rearing conditions upon later learning abilities and activity in the albino rat

The present study was designed to investigate the effects of crowding and preexposure and the time of treatment upon later learning and activity in the male albino rat. The subjects were reared from birth to adulthood in either crowded or unerowded and preexposed or nonpreexposed conditions. They were tested at maturity on maze learning and maze reversal and in visual discrimination tasks. Activity levels were measured in the open field. It was hypothesized that 1) subjects which received treatment early would be superior performers on maze and visual discrimination, 2) there would no significant differences in discrimination performance between the subjects which were- preexposed early and the subjects which were preexposed late, 3) the subjects which received treatment during the entire rearing would be superior performers on both learning tasks, and 4) subjects which were neither crowded nor preexposed wrould be the poorest performers. No hypothesis was advanced about activity. Neither of the independent variables had significant interpretable effects on any of the dependent variables.