Cognitive demand of human sensorimotor performance during an extended space mission: a dual-task study.
BACKGROUND
Two previous single-case studies found that the dual-task costs of manual tracking plus memory search increased during a space mission, and concluded that sensorimotor deficits during spaceflight may be related to cognitive overload. Since dual-task costs were insensitive to the difficulty of memory search, the authors argued that the overload may reflect stress-related problems of multitasking, rather than a scarcity of specific cognitive resources. Here we expand the available database and compare different types of concurrent task.


METHODS
Three subjects were repeatedly tested before, during, and after an extended mission on the International Space Station (ISS). They performed an unstable tracking task and four reaction-time tasks, both separately and concurrently. Inflight data could only be obtained during later parts of the mission.


RESULTS
The tracking error increased from pre- to in flight by a factor of about 2, both under single- and dual-task conditions. The dual-task costs with a reaction-time task requiring rhythm production was 2.4 times higher than with a reaction-time task requiring visuo-spatial transformations, and 8 times higher than with a regular choice reaction-time task.


CONCLUSIONS
Long-term sensorimotor deficits during spaceflight may reflect not only stress, but also a scarcity of resources related to complex motor programming; possibly those resources are tied up by sensorimotor adaptation to the space environment.
Bock
Otmar
O
Institute of Physiology and Anatomy, German Sport University, 50927 Cologne, Germany. bock@dshs-koeln.de
Weigelt
Cornelia
C
Bloomberg
Jacob J
JJ
D000328:Adult; D056228:Feedback, Sensory / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology*; D013026:Space Flight; D014893:Weightlessness / Q000009:adverse effects*