title: Performance Monitoring in Medication-Naïve Children with Tourette Syndrome.
abstract: BACKGROUND
  Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder and its impact on cognitive development needs further study. Evidence from neuropsychological, neuroimaging and electrophysiological studies suggests that the decline in tic severity and the ability to suppress tics relate to the development of self-regulatory functions in late childhood and adolescence. Hence, tasks measuring performance monitoring might provide insight into the regulation of tics in children with TS.
  
  
  METHODS
  Twenty-five children with TS, including 14 with comorbid Attention-deficit/ hyperactivity disorder (ADHD), 39 children with ADHD and 35 typically developing children aged 8-12 years were tested with a modified Eriksen-Flanker task during a 34-channel electroencephalography (EEG) recording. Task performance, as well as stimulus-locked and response-locked event-related potentials (ERP) were analyzed and compared across groups.
  
  
  RESULTS
  Participants did not differ in their behavioral performance. Children with TS showed higher amplitudes of an early P3 component of the stimulus-locked ERPs in ensemble averages and in separate trial outcomes, suggesting heightened orienting and/or attention during stimulus evaluation. In response-locked averages, children with TS had a slightly higher positive complex before the motor response, likely also reflecting a late P3. Groups did not differ in post-response components, particularly in the error-related negativity (ERN) and error-related positivity (Pe).
  
  
  CONCLUSIONS
  These findings suggest that children with TS may employ additional attentional resources as a compensatory mechanism to maintain equal behavioral performance.
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway.
authors.forename: Heike
authors.initials: H
authors.lastname: Eichele
authors.affiliation: Department of Biological and Medical Psychology, University of BergenBergen, Norway; K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of BergenBergen, Norway; Section for Neurophysiology, Department of Neurology, Haukeland University HospitalBergen, Norway.
authors.forename: Tom
authors.initials: T
authors.lastname: Eichele
authors.affiliation: Department of Psychiatry, Haukeland University HospitalBergen, Norway; Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of BergenBergen, Norway.
authors.forename: Ingvar
authors.initials: I
authors.lastname: Bjelland
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen Bergen, Norway.
authors.forename: Marie F
authors.initials: MF
authors.lastname: Høvik
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway.
authors.forename: Lin
authors.initials: L
authors.lastname: Sørensen
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway.
authors.forename: Heidi
authors.initials: H
authors.lastname: van Wageningen
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen Bergen, Norway.
authors.forename: Marius Kalsås
authors.initials: MK
authors.lastname: Worren
authors.affiliation: Department of Biological and Medical Psychology, University of BergenBergen, Norway; K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of BergenBergen, Norway; Department of Psychiatry, Haukeland University HospitalBergen, Norway.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hugdahl
authors.affiliation: K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of BergenBergen, Norway; Child and Adolescent Mental Health Center, Mental Health Services Capital RegionCopenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark.
authors.forename: Kerstin J
authors.initials: KJ
authors.lastname: Plessen
keywords: ADHD; P3; Tourette syndrome; children; event-related potentials; performance monitoring