Multivariate analysis of EEG activity indexes contingent attentional capture

Neuroimage. 2021 Feb 1:226:117562. doi: 10.1016/j.neuroimage.2020.117562. Epub 2020 Nov 12.

Abstract

An extensive body of work has shown that attentional capture is contingent on the goals of the observer: Capture is strongly reduced or even eliminated when an irrelevant singleton stimulus does not match the target-defining properties (Folk et al., 1992). There has been a long-standing debate on whether attentional capture can be explained by goal-driven and/or stimulus-driven accounts. Here, we shed further light on this matter by using EEG activity (raw EEG and alpha power) to provide a time-resolved index of attentional orienting towards salient stimuli that either matched or did not match target-defining properties. A search display containing the target stimulus was preceded by a spatially uninformative singleton cue that either matched the color of the upcoming target (contingent cues), or that appeared in an irrelevant color (non-contingent cues). Multivariate analysis of raw EEG and alpha power revealed preferential tuning to the location of both contingent and non-contingent cues, with a stronger bias towards contingent than non-contingent cues. The time course of these effects, however, depended on the neural signal. Raw EEG data revealed attentional orienting towards the contingent cue early on in the trial (>156 ms), while alpha power revealed sustained spatial selection in the cued locations at a later moment in the trial (>250 ms). Moreover, while raw EEG showed stronger capture by contingent cues during this early time window, an advantage for contingent cues arose during a later time window in alpha band activity. Thus, our findings suggest that raw EEG activity and alpha-band power tap into distinct neural processes that index separate aspects of covert spatial attention.

Keywords: Alpha power; Attentional capture; Backward decoding models; Contingent capture; EEG; Forward encoding models; Multivariate EEG analyses; Raw EEG.

MeSH terms

  • Adult
  • Alpha Rhythm / physiology*
  • Attention / physiology*
  • Brain / physiology*
  • Cues
  • Electroencephalography
  • Female
  • Humans
  • Male
  • Multivariate Analysis
  • Orientation, Spatial / physiology*
  • Reaction Time / physiology
  • Young Adult