Odor identification ability predicts executive function deficits following sleep deprivation

Odor identification ability is sensitive to prefrontal lobe dysfunction and preliminary evidence suggests that this capacity may decline with prolonged wakefulness. We hypothesized that declines in odor identification during a single night of sleep loss might, therefore, be predictive of prefrontal lobe executive function deficits following an additional night of sleep deprivation. Change scores between two administrations of the University of Pennsylvania Smell Identification Test (SIT) during 24 hr of sleep deprivation were used to predict performance on the Wisconsin Card Sorting Test (WCST) following 45 hr of wakefulness in 54 healthy adults. Declines in SIT performance predicted poorer performance on the WCST following an additional night of sleep loss. These findings suggest that individual differences in vulnerability to the effects of sleep loss on odor identification ability are predictive of deficits in executive functioning following additional wakefulness. Odor identification ability may provide an unobtrusive method for assessing vulnerability to sleep deprivation.

Sleep deprivation reduces perceived emotional intelligence and constructive thinking skills

BACKGROUND AND PURPOSE

Insufficient sleep can adversely affect a variety of cognitive abilities, ranging from simple alertness to higher-order executive functions. Although the effects of sleep loss on mood and cognition are well documented, there have been no controlled studies examining its effects on perceived emotional intelligence (EQ) and constructive thinking, abilities that require the integration of affect and cognition and are central to adaptive functioning.

PATIENTS AND METHODS

Twenty-six healthy volunteers completed the Bar-On Emotional Quotient Inventory (EQi) and the Constructive Thinking Inventory (CTI) at rested baseline and again after 55.5 and 58 h of continuous wakefulness, respectively.

RESULTS

Relative to baseline, sleep deprivation was associated with lower scores on Total EQ (decreased global emotional intelligence), Intrapersonal functioning (reduced self-regard, assertiveness, sense of independence, and self-actualization), Interpersonal functioning (reduced empathy toward others and quality of interpersonal relationships), Stress Management skills (reduced impulse control and difficulty with delay of gratification), and Behavioral Coping (reduced positive thinking and action orientation). Esoteric Thinking (greater reliance on formal superstitions and magical thinking processes) was increased.

CONCLUSIONS

These findings are consistent with the neurobehavioral model suggesting that sleep loss produces temporary changes in cerebral metabolism, cognition, emotion, and behavior consistent with mild prefrontal lobe dysfunction.