Abstract
The Simon task is used to study interference from irrelevant spatial information. Interference is manifested by longer reaction times when the required response –based on non-spatial features- is spatially incompatible with stimulus position. Interference is greater when incompatible trials are preceded by compatible trials (compatible-incompatible sequence) than when they are preceded by incompatible trials (incompatible-incompatible sequence). However, the relationships between spatial attention, interference and cognitive control have not been investigated. In the present study, we distinguished three experimental conditions according to sequential effects: same mappings (SM, compatible-compatible/incompatible-incompatible sequences: low interference), opposite mappings (OM, compatible-incompatible/incompatible-compatible sequences: high interference) and unrelated mappings (UM, central-compatible/central-incompatible sequences: intermediate interference). The negativity central contralateral (N2cc, a correlate of prevention of spatial response tendencies) was larger in OM than in SM, indicating greater cognitive control for greater interference. Furthermore, N2cc was larger in UM than in SM/OM, indicating lower neural efficiency for suppressing spatial tendencies of the response after central trials. Attentional processes (negativity posterior contralateral) were also delayed in UM relative to SM/OM, suggesting attentional facilitation by similar sets of attentional shifts in successive trials. Overall, the present findings showed that cognitive control is modulated by the magnitude of interference and pre-activation of monitoring mechanisms.
Highlights
Prepotent tendency to respond towards the stimulus position, as it is irrelevant to task performance and can lead to erroneous responses
Event-related potential (ERP) studies have focused on electrophysiological correlates of the Simon effect by employing the lateralized readiness potential (LRP)[17]
The LRP is obtained by a subtraction procedure that isolates an increase in activity at central electrode sites contralateral to the hand involved in preparing a movement
Summary
Prepotent tendency to respond towards the stimulus position, as it is irrelevant to task performance and can lead to erroneous responses. In incompatible trials, LRP shows an early and transitory positive dip related to response selection based on stimulus position This early dip delays the onset of the negative polarity wave that is the correlate of response selection based on task instructions. A Simon task study demonstrated that N2cc was larger in the incompatible than in the compatible condition[24] This finding was attributed to enhanced activity preventing the spatial tendency of the response and implementing the appropriate response in the incompatible condition. It supported the view of N2cc as an AMM taking place during Simon-type tasks[7,25]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
