Rats’ location during conditioned suppression training

Authors

Rick A. Bevins, University of Nebraska-LincolnFollow
John J. B. Ayres, University of Massachusetts, Amherst

Date of this Version

January 1992

Comments

Published in Animal Learning & Behavior 20:1 (1992), pp. 8-16. Copyright 1992 Psychonomic Society, Inc. Used by permission. http://www.psychonomic.org/

Abstract

Freezing is often cited as the interfering behavior responsible for barpress conditioned-suppression. However, auditory cues that precede shock can evoke more freezing than can visual cues despite producing similar suppression. In two experiments, we sought to resolve this paradox by measuring rats’ location in the box in addition to recording freezing during conditioned-suppression training to tones and lights. Tone evoked more freezing than light but similar suppression. During both cues, rats left the bar and dipper areas and moved to the lower middle and rear of the box. When the bar was then removed and the dipper entry sealed, the preference for the middle and rear of the box disappeared. Apparently, frightened rats do not simply prefer the middle and rear of our box. The fact that rats leave the bar and dipper areas equally during both auditory and visual cues explains how the two cues can foster similar suppression despite evoking different levels of freezing. But the fact that rats leave the bar and dipper areas at all remains to be explained.