Effects of food and water deprivation on the performance of response motivated by acquired fear.

Abstract

On the basis of Hull''s drive-summation hypothesis, it was predicted that a fear-motivated response would be augmented by the addition of an irrelevant appetitional need or a combination of irrelevant needs and that the level of augmentation would be a direct function of the level of deprivation. Eighty-four rats were fear conditioned, after which they were put on a 23-hr, food- and water-deprivation schedule. On the 7th and 8th days following this, subjects were given 25 trials of fear-motivated hurdle jumping under 6 different combinations of food and water deprivation. Median reciprocals of latency measures indicated that the rank order of performance on the 2nd day of testing and on the last block of 5 trials was consistent with Hull''s drive-summation hypothesis.