The effect of anoxia on the retention of a discrimination habit.

Abstract

Six groups of rats were trained in one session on a horizontal-vertical discrimination problem to a criterion of learning. One group was then exposed to anoxia (simulating an altitude of 20,000 ft. for 10 min.) 30 sec. after completing the last criterion trial. Four additional groups were subjected to anoxia 2 min., 15 min., 1 hr., and 4 hr., respectively, after meeting the criterion. A sixth group constituted the normal controls. Following a period of two days, all groups were required to relearn the same discrimination. The results showed that significant deficits in retention occurred in the groups subject to anoxia within 2 min., with the magnitude of the deficit inversely related to the criterion-anoxia interval. The remaining anoxic groups did not differ in retention with the control group. These results were discussed in terms of a perseveration theory of memory.