title: Subthreshold muscle twitches dissociate oscillatory neural signatures of conflicts from errors.
abstract: We investigated the neural systems underlying conflict detection and error monitoring during rapid online error correction/monitoring mechanisms. We combined data from four separate cognitive tasks and 64 subjects in which EEG and EMG (muscle activity from the thumb used to respond) were recorded. In typical neuroscience experiments, behavioral responses are classified as "error" or "correct"; however, closer inspection of our data revealed that correct responses were often accompanied by "partial errors" - a muscle twitch of the incorrect hand ("mixed correct trials," ~13% of the trials). We found that these muscle twitches dissociated conflicts from errors in time-frequency domain analyses of EEG data. In particular, both mixed-correct trials and full error trials were associated with enhanced theta-band power (4-9Hz) compared to correct trials. However, full errors were additionally associated with power and frontal-parietal synchrony in the delta band. Single-trial robust multiple regression analyses revealed a significant modulation of theta power as a function of partial error correction time, thus linking trial-to-trial fluctuations in power to conflict. Furthermore, single-trial correlation analyses revealed a qualitative dissociation between conflict and error processing, such that mixed correct trials were associated with positive theta-RT correlations whereas full error trials were associated with negative delta-RT correlations. These findings shed new light on the local and global network mechanisms of conflict monitoring and error detection, and their relationship to online action adjustment.
authors.affiliation: Department of Psychology, University of Amsterdam, The Netherlands; Department of Physiology, University of Arizona, United States. Electronic address: mikexcohen@gmail.com.
authors.forename: Michael X
authors.initials: MX
authors.lastname: Cohen
authors.affiliation: Department of Psychology, University of Amsterdam, The Netherlands; Inserm, Cognitive Neuroimaging Unit, Gif-sur-Yvette, France; Commissarìat à l'Energie Atomique, Neurospin Center, Gif-sur-Yvette, France; Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behavior, The Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: van Gaal
mesh_terms: D001683:Biological Clocks / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003220:Conflict, Psychological; D003657:Decision Making / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D055815:Young Adult
keywords: Cognitive control; Connectivity; EEG; Errors; Medial frontal cortex; Oscillations; Partial errors; Theta; Time-frequency