Related Experiment Videos
Central and parietal event-related lateralizations in a flanker task
Rita Willemssen1, Jöorg Hoormann, Joachim Hohnsbein
1Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany.
Psychophysiology
|August 21, 2004
Summary
Researchers identified a parietal lateralized activation (DEL) that reflects premotor response representation, distinct from the lateralized readiness potential (LRP). This finding clarifies the neural basis of response selection in cognitive tasks.
Area of Science:
- Cognitive Neuroscience
- Human Motor Control
- Electrophysiology
Background:
- Previous research identified the lateralized readiness potential (LRP) reflecting response activation.
- A parietal lateralized activation (direction encoding lateralization; DEL) was reported, potentially indicating earlier response side coding.
- The precise origin of DEL, distinguishing it from stimulus or attention factors, remained unclear.
Purpose of the Study:
- To investigate the neural basis of the direction encoding lateralization (DEL).
- To differentiate DEL from stimulus- or attention-related lateralizations.
- To determine if DEL reflects premotor response representation.
Main Methods:
- Utilized vertically directed arrow stimuli and vertical dimension responses.
- Manipulated stimulus onset asynchrony (SOA) to separate flanker-induced from target-induced lateralizations.
- Recorded electroencephalography (EEG) to measure LRP and DEL.
Main Results:
- Confirmed the presence of clear DELs, distinct from LRPs.
- Observed that DELs varied with experimental variables similarly to LRPs.
- Found DELs peaked earlier and had a more posterior topography compared to LRPs.
Conclusions:
- The direction encoding lateralization (DEL) reflects premotor response representation.
- DEL appears to be an earlier neural event than the lateralized readiness potential (LRP).
- The findings provide evidence for distinct neural processes in response selection.