Prolonged reduction of electrocortical activity predicts correct performance during rapid serial visual processing

Abstract

When two targets are shown in a rapid temporal stream of distractors, performance for the second target (T2) is typically reduced when presented between 200 and 500 ms after the first (T1). The present study used the steady-state visual evoked potential (ssVEP), a continuous index of electrocortical facilitation, to compare brain responses in trials with correct versus incorrect T2 responses. We found a reduction of the electrocortical response following T1 in trials with correct T2 identification. By contrast, incorrect T2 trials were characterized by enhanced electrocortical amplitude. Amplitude attenuation predictive of successful T2 report was sustained over time, suggesting a reduction of resources allocated to the distractor stream in correct trials. Across intertarget intervals, T2 performance was a linear function of the ssVEP amplitude reduction in correct trials, weighted by the stimulus onset asynchrony.