Behavior during shock exposure as a determinant of subsequent interference with shuttle box escape-avoidance learning in the rat

Two experiments with Sprague-Dawley rats determined the influence of behavior during shock on impairment of conventional shuttle escape-avoidance learning. Amount of activity during shock was manipulated by an explicit negative reinforcement procedure for nonmovement during an otherwise movement-producing shock. Only head and shoulder inactivity was required to escape shock in Exp I, whereas whole-body immobility was required in Exp II. Yoked groups received physically identical but inescapable shock treatments; unrestrained and restrained groups were not shock treated in either study. Results of both experiments indicate that of the 2 shock treatments, the escapable shock condition resulted in lower overall terminal movement levels during treatment shock as well as in greater subsequent impairment of shuttle box escape-avoidance performance. Maximum levels of interference were sustained for a longer period during testing following the escapable shock procedure in Exp II that involved whole-body inactivity. Results suggest that behavior during shock rather than shock uncontrollability may be the critical determinant of subsequent shuttle interference in the rat. Findings support a general competing-response conception of shuttle interference effects. (24 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).