The Utility of fMRI for Assessing and Predicting Individual Differences in Fatigue Vulnerability

Abstract : Several studies have shown that fatigue from inadequate sleep is associated with serious performance decrements, increases in safety risks, and adverse health costs. Little has been done to explore the nature of individual differences in performance or the degree to which these differences can be predicted prior to sleep loss. The present study sought to replicate studies in which brain activation may identify those individuals who are susceptible to the effects of sleep deprivation. Following baseline cognitive testing and an fMRI, 11 participants underwent a complete sleep-deprivation study in which they were repeatedly given a battery of surveys and cognitive and mood tests at 2-hr intervals for 23 hours. Near the end of the 30-hr period, an additional fMRI examination identical to the first was performed for each participant. While in the scanner, participants took two cognitive tasks (Sternberg memory tasks and a binary detection task) and a magnetic resonance spectroscopy scan. The results indicated individuals who perform poorly during long hours of wakefulness may not have the cognitive reserve necessary to resist the effects of sleep deprivation. More research is necessary to determine whether fMRI can be a useful tool in identification of individuals who are resistant to the effects of long hours of wakefulness.