Sleep deprivation elevates expectation of gains and attenuates response to losses following risky decisions.
OBJECTIVE
Using a gambling task, we investigated how 24 hours of sleep deprivation modulates the neural response to the making of risky decisions with potentially loss-bearing outcomes.


METHODS
Two experiments involving sleep-deprived subjects were performed. In the first, neural responses to decision making and reward outcome were evaluated. A second control experiment evaluated responses to reward outcome only.


METHODS
Healthy right-handed adults participated in these experiments (26 [mean age 21.3 years] in Experiment 1 and 13 [mean age 21.7 years] in Experiment 2.)


RESULTS
Following sleep deprivation, choices involving higher relative risk elicited greater activation in the right nucleus accumbens, signifying an elevated expectation of the higher reward once the riskier choice was made. Concurrently, activation for losses in the insular and orbitofrontal cortices was reduced, denoting a diminished response to losses. This latter finding of reduced insular activation to losses was also true when volunteers were merely shown the results of the computer's decision, that is, without having to make their own choice.


CONCLUSIONS
These results suggest that sleep deprivation poses a dual threat to competent decision making by modulating activation in nucleus accumbens and insula, brain regions associated with risky decision making and emotional processing.
Venkatraman
Vinod
V
Cognitive Neuroscience Laboratory, Duke-NUS Graduate Medical School, Singapore.
Chuah
Y M Lisa
YM
Huettel
Scott A
SA
Chee
Michael W L
MW
D000328:Adult; D000339:Affect; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D002755:Choice Behavior / Q000502:physiology; D003657:Decision Making / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D005715:Gambling / Q000523:psychology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009714:Nucleus Accumbens / Q000503:physiopathology; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D012718:Set, Psychology; D012892:Sleep Deprivation / Q000503:physiopathology / Q000523:psychology*