Elucidating Fluctuations of Visual Attention: Reaction Time Variability and Mind-Wandering Provide Complementary Insights

Sustained attention refers to the ability to maintain focus on a task over an extended period of time. However, sustaining attention is challenging, as there are inherent fluctuations between periods of good attention (stable and less error-prone) and poor attention (unstable and error-prone). Two main methodologies have been used to isolate these attentional fluctuations in visual attention tasks: objective and subjective approaches. The objective methodology analyzes intraindividual reaction time (RT) variability. For example, Esterman et al. (2013) revealed higher errors during periods of high RT variability (out-of-the-zone state) compared to periods of low variability (in-the-zone state). The subjective methodology uses thought probes to identify mind-wandering episodes (task-unrelated thoughts), that can be either intentional (i.e., deliberate) or unintentional (Seli, 2016). Although previous studies revealed higher error rates during out-of-the-zone and mind-wandering states, it is unclear whether those two methodologies isolate the same or different type of attentional fluctuations. This study compared the two approaches in a single Go/NoGo sustained attention task (N=38), objectively measuring attention via RT variability, and subjectively via intermittent thought probes administered every 30 trials. The entire task lasted approximately 40 minutes. If both methods isolate similar fluctuations, we hypothesize that the time spent out-of-the-zone should be higher during mind-wandering than during on-task periods. Our results revealed significantly higher time out-of-the-zone during mind-wandering (52.1%) compared to on-task periods (47.8%), suggesting the methods isolate, to some extent, similar aspects of fluctuations. However, time out-of-the-zone was significantly higher during intentional (57.7%) versus unintentional mind-wandering (49.7%), indicating higher overlap between the objective and subjective methods for deliberate mind-wandering rather that spontaneous. These findings suggest the two methods capture complementary information about attentional fluctuations and highlights the utility of combining objective and subjective methods to gain a comprehensive understanding of sustained attention and its lapses.