Effects of sleep deprivation on cognitive-motor functions and adaptive skill learning among medical residents across 26h night shifts

Sleep deprivation is a pervasive issue in medical training known to impair attention and specific motor abilities, yet its impact on integrated cognitive-motor performance and adaptive motor skill learning during real-world hospital shifts remains insufficiently understood. This study investigated potential declines in these domains across a 26-h night shift and following recovery sleep among medical residents utilizing a Virtual Reality version of the Color Trails Test. The protocol involved thirteen residents who underwent assessment two days prior to the shift, at four time points during the shift, and once more after at least 24 h of recovery sleep. By replicating the core cognitive demands of the classic test while incorporating three-dimensional manual movements, the assessment also included an adaptive module with intermittent left-right mirror reversal to evaluate learning under sleep loss conditions. Findings indicated that completion times improved across sessions, predominantly in mirror-reversal segments, whereas performance on regular segments stabilized following pre-shift practice. Conversely, interference cost increased towards the end of the shift and remained elevated post-shift, suggesting greater relative difficulty in the more demanding condition due to fatigue. Movement distance and speed followed the completion time pattern with progressive improvement. Ultimately, despite preserved motor learning, fatigue appeared to selectively impair higher-order cognitive control, specifically task switching and divided attention, suggesting that such reduced cognitive flexibility during extended shifts may compromise clinical performance even after recovery sleep.