P300-based Stroop study with low probability and target Stroop oddballs: the evidence still favors the response selection hypothesis.

This paper addresses the issue of the locus of action in cognitive processing during Stroop effects. It uses the P300 latency to assess stimulus processing effects, but, for the first time, under conditions in which Stroop stimuli are rare and target stimuli. The study was also concerned with demonstrating that apparent P300s during verbal responding are in fact uninterpretable due to contamination of EEG by speech-related artifact.