Spatial Scaling of the Profile of Selective Attention in the Visual Field

Abstract

Neural mechanisms of selective attention must be capable of adapting to variation in the absolute size of an attended stimulus in the ever-changing visual environment. To date, little is known regarding how attentional selection interacts with fluctuations in the spatial expanse of an attended object. Here, we use event-related potentials (ERPs) to investigate the scaling of attentional enhancement and suppression across the visual field. We measured ERPs while participants performed a task at fixation that varied in its attentional demands (attentional load) and visual angle (1.0° or 2.5°). Observers were presented with a stream of task-relevant stimuli while foveal, parafoveal, and peripheral visual locations were probed by irrelevant distractor stimuli. We found two important effects in the N1 component of visual ERPs. First, N1 modulations to task-relevant stimuli indexed attentional selection of stimuli during the load task and further correlated with task performance. Second, with increased task size, attentional modulation of the N1 to distractor stimuli showed a differential pattern that was consistent with a scaling of attentional selection. Together, these results demonstrate that the size of an attended stimulus scales the profile of attentional selection across the visual field and provides insights into the attentional mechanisms associated with such spatial scaling.

Event-related brain potentials reflect predictive coding of anticipated economic change

“…Over occipital regions, feedback stimuli generated an N1 component around 170 ms that increased in amplitude and decreased in latency as a function of inflation step. Previous studies have established that the visual N1 is sensitive to both exogenous factors, i.e., physical properties such as stimulus size and luminance (De Cesarei & Codispoti, 2006 ; Gannon, Knapp, Adams, Long, & Parks, 2016 ; Pfabigan et al, 2015 ; Wijers, Lange, Mulder, & Mulder, 1997 ) as well as endogenous factors such as selective attention in tasks requiring stimulus discrimination (Bradley, 2009 ; Hillyard, Vogel, & Luck, 1998 ). Accordingly, the effects of inflation step on the N1 could either reflect the size of feedback stimuli, which increased with inflation step, or increments in visual attention with the increasing size of gambles per inflation step (or a combination of the two).…”