Stimulus context and satiation.

Abstract

Previous studies have shown that the tendency for an animal to alternate between two successive choices in a T-maze is high. Yet prior exposure in a box outside the maze to the color of one of the alternatives, or exposure to one of the goal boxes of the maze itself produces little or no tendency to avoid the exposure color. In this study 12 naive albino rats were permitted to explore the starting stem and choice point of a T-maze. During this exploration period, both arms were either white or black, and glass doors prevented the animal from entering the goal arms and thus making a choice. Each animal was tested at three exposure intervals: one minute, 15 minutes and 30 minutes. Four trials at each interval permitted control of color and position preferences. The test trial involved a free choice with one of the two arms converted to the opposite of the exposure color. With exposures of 15 and 30 minutes there was a significant tendency to avoid the exposure color. The two times were not significantly different from each other, nor was the effect of the one-minute exposure different from chance. The results exclude an exposure by active choice on the part of the animal as the necessary condition for the demonstration of satiation, and point to the context of the stimulus as the important determiner of sameness between the exposure and test stimuli.