Performance Changes at Moderately High Altitude: Short-Term Memory Measured by Free Recall

Abstract

Short-term memory for common English words was tested both at 3800 m altitude and at sea level. Recall for half the lists was tested immediately and half after 30 sec. delay. 18 Ss were run at both altitudes in a counterbalanced design. The words were presented serially in 10-item lists at a rate of 1 sec. each. Standard physiological tests showed significant reaction to the hypoxia. No significant change in total recall scores was found; however, improvement on some items cancelled out the slight decrement in others. These differential changes at altitude were a function of the serial positions of the items. The interaction was significant but transitory. The order-of-recall of the items reflected the differential recall frequencies and also showed a significant interaction between recall interval and altitude. The results are discussed in terms of proactive inhibition and increased generalized drive, possibly related to autonomic arousal at high altitude.