The influence of inhibition of response on event-related potentials and reaction time in the STROOP task

We aimed to study the psychophysiological processes that cause a physiological and reaction time Stroop effect with and without inhibition of response on stimuli. Participants (n = 26) performed two Stroop tasks. The stimuli were Russian words «green» or «red» written in green or red font. In the first task participants had to recognize words by pressing different keys depending on the font color. In the second task they were asked to ignore the word «red» in red or green font and to press the different keys depending on the font color to the word «green». We recorded reaction time and event-related potentials (ERPs) to stimuli. As a result, we found a reaction time Stroop effect on the word «red» (the first task), the word «green» (the second task). The reaction time on the word «green» was greater at 113 ms in the second task comparing to the first task. The differences in the amplitude of the ERPs (P50, N100, P300) allow to localize the Stroop effect at the early and late latency and to indicate the distinctive psychophysiological processes involved in the task performance with and without inhibition of response.