Even a little sleepiness influences neural activation and clinical reasoning in novices

Sleepiness influences alertness and cognitive functioning and impacts many aspects of medical care, including clinical reasoning. However, dual processing theory suggests that sleepiness will impact clinical reasoning differently in different individual, depending on their level of experience with the given condition. Our aim, therefore, was to examine the association between clinical reasoning, neuroanatomical activation, and sleepiness in senior medical students.

Our methodology replicated an earlier study but with novices rather than board-certified physicians. Eighteen final-year medical students answered validated multiple-choice questions (MCQs) during an fMRI scan. Each MCQ was projected in three phases: reading, answering, and reflection (modified think aloud). Echo-planar imaging (EPI) scans gave a time series that reflected blood oxygenation level dependent (BOLD) signal in each location (voxel) within the brain. Sleep data were collected via self-report (Epworth Sleepiness Scale) and actigraphy. These data were correlated with answer accuracy using Pearson correlation.

Analysis revealed an increased BOLD signal in the right dorsomedial prefrontal cortex (P < .05) during reflection (Phase 3) associated with increased self-reported sleepiness (ESS) immediately before scanning. Covariate analysis also revealed that increased BOLD signal in the right supramarginal gyrus (P < .05) when reflecting (Phase 3) was associated with increased correct answer response time. Both patterns indicate effortful analytic (System 2) reasoning.

Our findings that novices use System 2 thinking for clinical reasoning and even a little (perceived) sleepiness influences their clinical reasoning ability to suggest that the parameters for safe working may be different for novices (eg, junior doctors) and experienced physicians.