Gambling When Sleep Deprived: Don't Bet on Stimulants

Abstract

Recent evidence suggests that sleep deprivation leads to suboptimal decision-making on the Iowa Gambling Task (IGT), a pattern that appears to be unaffected by moderate doses of caffeine. It is not known whether impaired decision-making could be reversed by higher doses of caffeine or by other stimulant countermeasures, such as dextroamphetamine or modafinil. Fifty-four diurnally active healthy subjects completed alternate versions of the IGT at rested baseline, at 23 and 46 h awake, and following a night of recovery sleep. After 44 h awake, participants received a double-blind dose of caffeine (600 mg), dextroamphetamine (20 mg), modafinil (400 mg), or placebo. At baseline, participants showed a normal pattern of advantageous performance, whereas both sleep-deprived sessions were associated with suboptimal decision-making on the IGT. Following stimulant administration on the second night of sleep deprivation, groups receiving caffeine, dextroamphetamine, or modafinil showed significant reduction in subjective sleepiness and improvement in psychomotor vigilance, but decision-making on the IGT remained impaired for all stimulants and did not differ from placebo. Decision-making returned to normal following recovery sleep. These findings are consistent with prior research showing that sleep deprivation leads to suboptimal decision-making on some types of tasks, particularly those that rely heavily on emotion processing regions of the brain, such as the ventromedial prefrontal cortex. Moreover, the deficits in decision-making were not reversed by commonly used stimulant countermeasures, despite restoration of psychomotor vigilance and alertness. These three stimulants may restore some, but not all, aspects of cognitive functioning during sleep deprivation.

Adenosine, Caffeine, and Performance: From Cognitive Neuroscience of Sleep to Sleep Pharmacogenetics

“…were not any better than placebo on the IGT (Killgore et al 2012). These findings are consistent with a previous study which evaluated the effect of caffeine on sleep-deprived IGT performance (Killgore et al 2007b).…”

“…Yet, perhaps the most important finding was the fact that although all three stimulants were highly effective at reducing subjective sleepiness and sustaining psychomotor vigilance relative to placebo, none of the pharmacologic agents provided any significant enhancement of decision-making performance on the IGT. In fact, performance was similar to placebo for all stimulant groups (Killgore et al 2012). It should be noted here that IGT performance was unrelated to self-reported sleepiness or psychomotor vigilance performance during the administration of the stimulants, which implies that the deficits observed in decision-making were independent of differences in alertness.…”

“…More recently, research has focused on clarifying the ways in which sleep deprivation may influence well-characterized, higher cognitive processes, such as mental heuristics and emotional biases that affect risk assessment and decision-making (Killgore et al 2012). For example, McKenna and colleagues (2007) revealed that when the possible outcomes from a gambling task were framed in terms of potential gains, sleep deprivation prompted subjects to take more risks compared to when they were well rested.…”

“…Sleep deprived individuals may tend to rely more upon automatic, as opposed to effortful, forms of cognitive processing (Killgore et al 2012). Emotional biasing is a form of automatic processing that may influence decision making.…”

Feedback Blunting: Total Sleep Deprivation Impairs Decision Making that Requires Updating Based on Feedback

“…Recent evidence suggests that stimulants such as caffeine may not be very effective as fatigue countermeasures in this context. 53 It would be informative to investigate whether caffeine restores only the instability in sustained attention during sleep deprivation, 40 but not the feedback blunting revealed in the current study.…”