Abstract
In daily life, our attention waxes and wanes despite our best efforts. Previous work has identified neural and behavioral signatures that track the dynamics of sustained attention (e.g., deBettencourt et al., Nat. Neurosci., 2015 & deBettencourt et al., Nat. Hum. Behav., 2019). For example, faster prepotent responses and lower multivariate decoding index worse attentional states. However, these studies have not examined how fluctuations of sustained attention interact with covert spatial attention. Either, sustained and spatial attention could covary synchronously or they could fluctuate independently. The goal of this study was to investigate the relationship between neural signatures of sustained and spatial attention using EEG. In this study, we presented participants with streams of rapidly appearing shapes in four quadrants on the screen. We manipulated spatial attention by cueing participants to covertly attend to one of the four quadrants and perform a visual sustained attention to response task (SART). Participants categorized whether the shapes in the cued location were circles or squares, and we manipulated the prepotent response (e.g., 85% circles vs. 15% squares). We verified that this task captured key behavioral signatures of sustained attention. Namely, participates made many more errors to the infrequent lure trials (i.e., squares) and faster prepotent responses preceded sustained attention lapses. Using multivariate pattern analysis of EEG data, we decoded sustained attentional state as well as the spatially attended quadrant. Intriguingly, even during moments of poor sustained attention, multivariate decoding of spatial attention was unimpaired. These results suggest sustained attention can wax and wane independently from spatial attention. This work provides new evidence that sustained and spatial attention are distinct, and provides important evidence to situate sustained attention in the broader attention taxonomy.