O047 Exploring performance across 31h of wakefulness: a task switching paradigm

Abstract Introduction In sustained operations, managing multiple complex tasks in dynamic environments is cognitively demanding, especially under fatigue, which slows cognitive processing, impairs attention, and increases errors. This study examined how sustained wakefulness affects task switching performance. Methods Twenty-six healthy participants underwent a 31-hour sustained wakefulness protocol, completing multiple testing sessions at 11:00h, 17:00h, 23:00h, 05:00h and 11:00h. The task-switching paradigm involved alternating between a math task and a spatial-rotation task (manikin). Performance was assessed via reaction time (RT), accuracy (proportion of correct responses), and throughput (measure of speed-accuracy trade-off) across four transition types: math-to-math, manikin-to-manikin, manikin-to-math, and math-to-manikin. Data were analysed using linear mixed models. Results Wakefulness had a significant main effect on mean RT (p=.01) and mean proportion of correct responses (p<.001) but not on throughput (p=.40). Transition type impacted performance with significant main effects of transition type on RT (p<.001) and throughput (p<.001). The proportion of correct responses was consistent across transition types; however, when transitioning from “different”, i.e., manikin-to-math, there was a reduction in mean reaction time compared to “same”, i.e., manikin-to-manikin transition types (p<.001). Discussion Switching costs were dependent on the preceding and the following task. When transitioning between two different tasks, there was a speed/accuracy trade-off observed with participants slowing down to maintain accuracy. To improve/maintain switching performance during sustained operations, it is vital to address these performance outcomes. Using human-centred interface designs can reduce demands, especially when individuals are fatigued.