Environmental control of defensive reactions to footshock

Abstract

Footshock given immediately after rats are placed in a strange inescapable environment produces no diminution in movement. However, if a brief exploration period is allowed before shock, freezing is the dominant defensive behavior seen. Thus, the topographical similarity of postshock reactions to unconditioned defensive behaviors elicited by a cat also involves a similar flight-to-freezing shift when the subject is permitted prior familiarization with the inescapable threat situation.