Abstract
Attention may be oriented exogenously (i.e., involuntarily) to the location of salient stimuli, resulting in improved perception. However, it is unknown whether exogenous attention improves perception by facilitating processing of attended information, suppressing processing of unattended information, or both. To test this question, we measured behavioral performance and cue-elicited neural changes in the electroencephalogram as participants (N = 19) performed a task in which a spatially non-predictive auditory cue preceded a visual target. Critically, this cue was either presented at a peripheral target location or from the center of the screen, allowing us to isolate spatially specific attentional activity. We found that both behavioral performance and visual-cortical processing were enhanced at the location of a peripheral cue, but that both measures were equivalent to baseline (i.e., following a central cue) at the unattended location. These results suggest that exogenous attention operates solely via facilitation of information at an attended location.
Statement of Relevance While a great deal of psychophysical research has been done investigating the mechanisms of exogenous attention, the results of these studies have been equivocal as to whether exogenous attention operates via facilitation and/or suppression. Here, we applied a classic psychophysical cost-benefit analysis while also utilizing a novel research approach: employing a cross-modal cueing paradigm in which cue-elicited attentional activity may be measured without contamination by the visual processing of the cue itself. Using this innovative cross-modal approach, we are able to establish a novel congruence between behavior and neural activity following a cue. We find that both behavior and attention-mediated changes in visual-cortical activity are enhanced at the location of a cue prior to the onset of a target, but that neural activity at an unattended target location is equivalent to that following a central cue that does not direct attention – demonstrating that exogenous attention operates solely via facilitation.
Competing Interest Statement
The authors have declared no competing interest.
