ABSTRACT
The aim of this study was to investigate how information carried by a cue stimulus modulate event-related potentials (ERPs) to a subsequent target stimulus which either calls for an overt response (Go stimulus) or no response (Nogo stimulus). One of the cues predicted the likely appearance of the Go stimulus (Go cue) whereas the other cue predicted the likely appearance of the Nogo stimulus (Nogo cue). Our results showed that unpredicted Nogo stimuli elicited enlarged N200 component. This finding supports the notion that Nogo N200 reflects response inhibition processes, i.e., the amplitude of the N200 is a function of the difficulty of response inhibition. In other words, increased N200 to Nogo stimuli following Go cues might be related to increased efforts in activating the response inhibition system thereby interrupting preparations to respond.
Subject(s)
Cues , Event-Related Potentials, P300/physiology , Mental Processes/physiology , Adolescent , Adult , Cognition/physiology , Electrophysiology , Female , Humans , Male , Photic StimulationABSTRACT
In a series of experiments, a color discrimination task was combined with a lexical decision task. Words and non-words that appeared in the relevant color elicited attention-related event-related potential (ERP) components (anterior positivity, posterior N2 and N2b). The results of the recognition tasks, that investigated the retention of the words, were not closely related to the emergence of these ERP components. These findings show that instead of being the correlates of a filtering mechanism confining lexical processing to stimuli in relevant color, the attention-related ERP components are correlates of late selection processes, ensuring task-related stimulus evaluation.