title: EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.
abstract: Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz), followed by a later alpha-band (8-12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.
authors: Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands. mikexcohen@gmail.com
authors: Michael X
authors: MX
authors: Cohen
authors: K Richard
authors: KR
authors: Ridderinkhof
mesh_terms: D003220:Conflict, Psychological; D004566:Electrodes; D004569:Electroencephalography; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D010296:Parietal Lobe / Q000502:physiology*