Examining the Role of Attention and Sensory Stimulation in the Attentional Repulsion Effect

EXPRESS: Can arrows change the subjective perception of space? Exploring symbolic attention repulsion

The attention repulsion effect (ARE) refers to distortions in the perception of space for areas nearby the focus of attention. For instance, when attending to the right-hand side of the visual field, objects in central vision may appear as though they are shifted to the left. The phenomenon is likely caused by changes in visual cell functioning. To date, research on the ARE has almost exclusively used exogenous manipulations of attention. In contrast, research exploring endogenous attention repulsion has been mixed, and no research has explored the effects of non-predictive arrow cues on this phenomenon. This gap in the literature is unexpected, as symbolic attention appears to be a unique form of attentional orienting compared to endogenous and exogenous attention. Therefore, the current study explored the effects of symbolic orienting on spatial repulsion and compared it to an exogenously generated ARE. Across four experiments, both exogenous and symbolic orienting resulted in AREs; however, the magnitude of the symbolic ARE was smaller than the exogenous ARE. This difference in magnitude persisted, even after testing both phenomena using stimulus timing parameters known to produce optimal effects in traditional attentional cueing paradigms. Therefore, compared to symbolic attention, it appears that exogenous manipulations may tightly constrict attention resources on the cued location, in turn potentially influencing the functioning of visual cells for enhanced perceptual processing.

Microsaccade dynamics in the attentional repulsion effect

A briefly flashed peripheral cue has been shown to repulse the perceived position of a subsequently presented foveal probe - a bias called the Attentional Repulsion Effect (ARE). While this bias has originally been assumed to reflect attentional capturing by the cue, its attentional nature has recently been questioned. To investigate the ARE's attentional properties, we recorded microsaccades as an attentional marker in the ARE paradigm. Microsaccades, small fixational eye movements performed during fixation, have previously been described to reflect the dynamics of spatial attention deployment. Our results favor an attentional explanation for the ARE: In trials in which an ARE was found, microsaccades were directed more often toward the cue, presumably reflecting the covert shift of attention. In contrast, more cue-incongruent microsaccades were observed in trials in which no ARE was found. Therefore, both repulsion as well as measured microsaccade modulations, are most likely an outcome of the preceding shifts of covert attention.

Attentional repulsion effects produced by feature-guided shifts of attention

Attention shifts to particular objects in the visual field can distort perceptual location judgments. Visual stimuli are perceived to be shifted away from the current focus of attention (the attentional repulsion effect [ARE]). Although links between repulsion effects and stimulus-driven exogenous attentional capture have been demonstrated conclusively, it remains disputed whether AREs can also be elicited as a result of feature-guided attention shifts that are controlled by endogenous task sets. Here we demonstrate that this is indeed the case. Color singleton cues that appeared together with equiluminant gray items triggered repulsion effects only if they matched a current task-relevant color but not when their color was irrelevant. When target-color and nontarget-color singleton cues appeared in the same display, AREs emerged relative to the position of the target-color cue. By obtaining independent behavioral measures of perceptual repulsion and electrophysiological measures of attentional capture by target-color cues, we also showed that these two phenomena are correlated. Individuals who were more susceptible to attentional capture also produced larger AREs. These results confirm the existence of links between task-set contingent attentional capture and AREs. They also provide the first direct demonstration of the attentional nature of these effects with online brain activity measures: perceptual repulsion arises as the result of prior feature-guided attention shifts to specific locations in the visual field.