Spatially specific attention mechanisms are sensitive to competition during visual search
Journal
Journal of Cognitive Neuroscience
Journal Volume
31
Journal Issue
8
Pages
1248-1259
Date Issued
2018
Author(s)
Abstract
■ Extensive studies have focused on selection mechanisms during visual search. One important influence on these mechanisms is the perceptual characteristics of the stimuli. We investigated the impact of perceptual similarity between targets and nontargets (T-N similarity) in a visual search task using EEG. Participants searched for a predefined target letter among five nontargets. The T-N similarity was manipulated with three levels: high, middle, and low. We tested for the influences of T-N similarity on an ERP (e.g., N2pc) and alpha oscillations. We observed a significant N2pc effect across all levels of similarity. The N2pc amplitude was reduced and occurred later for high similarity relative to low and middle similarities. We also showed that the N2pc amplitude was inversely correlated with the RTs across all similarities. Importantly, we found a significant alpha phase adjustment about the same time as the N2pc for high similarity; by contrast, no such effect was observed for middle and low similarities. Finally, we showed a positive correlation between the phase-locking value and the N2pc—the stronger the alpha phase-locking value, the larger the N2pc, when the T-N similarity was high. In conclusion, our results provide novel evidence for multiple competitive mechanisms during visual search. ■. ? 2019 Massachusetts Institute of Technology.
Subjects
Alpha phase; Attention mechanisms; Competitive mechanisms; Perceptual similarity; Phase locking value; Positive correlations; Selection mechanism; Visual search; Locks (fasteners); adult; article; attention; competition; controlled study; electroencephalogram; evoked response; human; oscillation; alpha rhythm; attention; depth perception; electroencephalography; female; male; pattern recognition; physiology; young adult; Adult; Alpha Rhythm; Attention; Electroencephalography; Evoked Potentials; Female; Humans; Male; Pattern Recognition, Visual; Space Perception; Young Adult
Type
journal article