Attentional lapses and mind wandering during the maintenance of visual attention over varying durations

Sustaining the focus of our attention is effortful and cannot be maintained indefinitely. Our minds naturally wander, necessitating effortful control of attention to maintain focus and resist distraction from external events or internally generated task-unrelated thoughts. However, the mechanisms underlying failures of sustained attention remain unclear, perhaps because it has proven challenging to experimentally isolate processes engaged to direct and maintain attention over short timescales from those supporting prolonged task engagement. This study investigates sustained attention and the occurrence of mind wandering in a modified version of the Sustained Attention to Cue Task, in which attention must be maintained on trials for a variable length of time to correctly detect a visual target stimulus at a spatially cued location. Latent growth curve models assessed changes in detection accuracy based on how long attention had to be maintained on trials, independent of changes occurring over the course of the entire task session. We observed that detection accuracy was dependent on the duration that attention had to be maintained on trials. In contrast, accuracy did not change as a function of time-on-task. Experience sampling mind wandering probes also caught individuals with less focus and more task-unrelated thought on trials requiring longer periods of sustained attention compared to shorter periods, particularly on later trials of the task. These findings suggest attention wanes over time, but mechanisms responsible for the maintenance of attention at short timescales may be separable from those psychological processes contributing to the degradation in task performance across longer timescales.