TITLE:
How the Brain Process Stimulus-Response Conflict? New Insights from Lateralized Readiness Potentials Scalp Topography and Reaction Times
AUTHORS:
Marc E. Lavoie, Johannes E. A. Stauder
KEYWORDS:
Lateralized Readiness Potentials; Mixed-Blocked Designs; Stimulus Response-Compatibility; Reaction Times
JOURNAL NAME:
Journal of Behavioral and Brain Science,
Vol.3 No.1,
February
27,
2013
ABSTRACT: Stimulus-Response Compatibility
(SRC) refers to the fact that some tasks are performed easier and better than others
because of the way stimuli and responses are paired with each other. To assess the
brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy
and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness
Potentials: LRP) modulations in a positional blocked and a conditional mixed design
in twelve university students. Results revealed that the performance was less accurate
and the RTs, as well as the LRP onset, were delayed under the mixed conditional
design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset
latency in the mixed design. Consistent with these findings, smaller peak activation
at fronto-central areas suggests that more selective inhibition is needed in a mixed
design context. Despite a smaller activation, the topographical distribution is
similar in both designs. These results indicate that the translation time between
stimulus- and response codes are greater under the mixed instruction, while the
similar LRP topography suggests that common neural structures underlie LRPs in response
to both type of designs.