Tracking neural markers of template formation and implementation in attentional inhibition under different distractor consistency

Abstract

To perform challenging visual search tasks, attention should be selectively allocated to promote targets and inhibit distractors. Rejection templates based on the distractor’s feature can be built to constrain the search process by filtering-out matched stimuli. We measured electroencephalography (EEG) of human participants when they performed a visual search task under conditions in which the distractor cues were constant within a block (fixed-cueing) or changed on a trial-by-trial basis (varied-cueing). Sustained representation of the cued colors could be decoded from the whole-brain EEG signal during the retention interval in the fixed-cueing condition, implying a formed rejection template. By contrast, transient representation of the cued colors was observed in the varied-cueing condition only after cue onset with significant but lower decoding accuracy than the fixed-cueing condition. The differential neural representations of the to-be-ignored color in the two cueing conditions agreed with the visual search performance that the fixed-cueing condition demonstrated a larger inhibition benefit of the distractor cueing than the varied-cueing condition. During the retention interval, we also observed stronger posterior alpha lateralization and mid-frontal theta/beta power in the varied-cueing condition, indicating the cognitive costs in template formation caused by the trialwisely change of distractor colors. The stable template formed in the fixed-cueing condition was utilized to inhibit the matched distractors in the search array and this was accompanied by larger mid-frontal theta activity. Taken together, our findings highlighted the critical roles of distractor consistency in linking template formation to successful distractor inhibition and the functional relevance of frontal theta activity in support of template formation and implementation.

Tracking neural correlates of prioritizing working memory representations through retrospective attentional strengthening

“…If the data support the non-target inhibition hypothesis, non-target representation will be inhibited by valid retro-cue. Since rejection template formation of distractor could achieve decoding accuracy of distractor information above (31), we would expect a higher decoding accuracy of non-target orientation classification in valid condition, but no difference in decoding accuracy of target orientation classification.…”