Cognitive functioning in long-duration head-down bed rest.

INTRODUCTION This report is one of a series on the Flight Analog Project, which is designed to lay the groundwork for a standard bed rest protocol. The Spaceflight Cognitive Assessment Tool for Windows (WinSCAT) is a self-administered battery of tests used on the International Space Station for evaluating cognitive functioning. Here, WinSCAT was used to assess cognitive functioning during extended head-down bed rest. METHODS There were 13 subjects who participated in 60 or 90 d of head-down bed rest and took WinSCAT during the pre-bed rest phase, the in-bed rest phase, and the post-bed rest (reconditioning) phase of study participation. RESULTS After adjusting for individual baseline performance, 12 off-nominal scores were observed out of 351 total observations during bed rest and 7 of 180 during reconditioning. No evidence was found for systematic changes in off-nominal incidence as time in bed rest progressed, or during the reconditioning period. DISCUSSION Cognitive functioning does not appear to be adversely affected by long-duration head-down bed rest. Individual differences in underlying cognitive ability and motivation level are likely explanations for the current findings.