| Abstract: | Conducted 4 experiments with a total of 132 male Wistar rats to examine the characteristics of stimuli that produce unconditioned defensive reactions. Results show that neither the sound nor the smell of a cat, or the sight of a dead cat, produced freezing, but that either a moving cat or dog, or the abrupt and rapid movement of an inanimate card, resulted in freezing and failure to approach the stimulus object. It is suggested that movement is a major factor in the initiation of defensive responses and that movement of a neutral stimulus may enhance the acquisition of defensive responses to that stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
