Effects of Multiple Cold Air Exposures on Delayed Matching to Sample Performance

Abstract

Abstract : Acute exposure to moderate cold impairs delayed matching to sample (DMS) performance in both animal and man. The effect of multiple cold air (2.6 + or - 0.6 C) exposures on DMS performance was investigated in this study. Twelve men performed the DMS task during a 45 minute (min) exposure to cold air on Day 1. Oxygen consumption (VO2) was measured concurrently. After completion of Day 1, subjects were assigned to two groups. Group W performed the DMS task on Days 2 to 11 in warm air (22 C) during a 45 min period before sitting in cold air for 45 min. Group C performed the DMS task during a 45 min exposure to cold air on days 2 to 11. On Day 12, all subjects were exposed to cold air as on Day 1. VO2 was measured concurrently on Days 4 to 8. DMS performance was significantly impaired in all subjects during exposure to cold air on Day 1 when compared to baseline DMS performance. Performance on the DMS was significantly different between the groups on Day 12. Group W performance was not different on Day 12 when compared to Day 1. Group C performance was not different from baseline on Day 12 and was significantly improved when compared to Day 1. VO2 was elevated in the cold but was not different between groups. VO2 was not different on Day 12 when compared to Day 1. DMS is affected by acute exposure to cold air. Performance on the DMS task improves with repeated cold air exposure only when the DMS task is repeatedly performed in cold air.