Cognitive function during acute cold exposure with or without sleep deprivation lasting 53 hours.
BACKGROUND
Cold exposure and sleep deprivation are independently associated with transient cognitive impairment, including difficulty in attention, reaction time, and executive function. The possible interactive effects of cold exposure and sleep deprivation on cognition have not previously been examined.


METHODS
Six apparently healthy young adult men participated in a within-subjects design with two counterbalanced 53-h protocols: 2-h cold exposure (10 degrees C) blocks every 24 h with normal sleep (Cold), and the same cold exposure in addition to 53 h of complete sleep deprivation (Cold + Sdep). Computerized cognitive tasks of attention, reaction time, and executive function were completed every 4 h during Cold + Sdep, and every 4 waking hours during Cold.


RESULTS
Cold was associated with a decline in attention over time (b = -0.06). Cold + Sdep was associated with greater attentional decline than Cold (b = -0.13), a significantly reduced speeded/reaction time performance (b = 0.02; b = -0.13), and a trend toward reduced cognitive inhibition over time (b = -0.10).


CONCLUSIONS
Findings suggest an additive effect of sleep deprivation to cold exposure in attention and reaction time, and a trend toward this pattern in aspects of executive functioning. These findings raise concern for errors when careful attention and speeded cognitive flexibility are necessary and optimal sleep and protection from the environment is not possible. Mechanisms are not entirely clear, but may be related to transient cerebrovascular or neurochemical changes, or direct physiological effects. Further work is needed to clarify mechanisms for the additive cognitive decline associated with cold exposure and sleep deprivation.
Spitznagel
Mary Beth
MB
Department of Psychology, Kent State University, Kent, OH, USA. spitznagelm@summa-health.org
Updegraff
John
J
Pierce
Katie
K
Walter
Kristen H
KH
Collinsworth
Tiffany
T
Glickman
Ellen
E
Gunstad
John
J
D000328:Adult; D001288:Attention; D003072:Cognition Disorders / Q000209:etiology*; D003080:Cold Temperature / Q000009:adverse effects*; D006801:Humans; D008297:Male; D011930:Reaction Time; D012892:Sleep Deprivation / Q000150:complications* / Q000523:psychology*; D055815:Young Adult