title: Electrophysiology of facilitation priming in obsessive-compulsive and panic disorders.
abstract: OBJECTIVE
  Repeated experience with stimuli often primes faster, more efficient neuronal and behavioural responses. Exaggerated repetition priming effects have previously been reported in obsessive-compulsive disorder (OCD), however little is known of their underlying neurobiology or disorder-specificity, hence we investigated these factors.
  
  
  METHODS
  We examined event-related potentials (ERPs) and behaviour while participants with OCD, panic disorder and healthy controls (20 per group) performed a Go/NoGo task which manipulated target repetition sequences.
  
  
  RESULTS
  Both clinical groups showed stronger reaction time (RT) priming than HCs, which in OCD was greater in a checking, than washing, subgroup. Both clinical groups had similar RT deficits and ERP anomalies across several components, which correlated with psychopathology and RT priming. In OCD alone, N1 latency tended to increase to repeated stimuli, correlated with O-C symptoms, whereas it decreased in other groups. OCD-checkers had smaller target P2 amplitude than all other groups.
  
  
  CONCLUSIONS
  Enhanced neural priming is not unique to OCD and may contribute to salient sensory-cognitive experiences in anxiety generally. These effects are related to symptom severity and occur to neutral stimuli and in the context of overall RT impairment, suggesting they may be clinically relevant and pervasive. The results indicate overlapping information-processing and neurobiological factors across disorders, with indications of OCD-specific trends and subgroup differences.
  
  
  CONCLUSIONS
  This first electrophysiological investigation of OCD priming in OCD to include anxious controls and OCD subgroups allows for differentiation between overlapping and OCD-specific phenomena, to advance neurobiological models of OCD.
authors.affiliation: Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, NSW, Australia; Graduate School of Medicine, University of Wollongong, NSW, Australia. Electronic address: sthomas@uow.edu.au.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Thomas
authors.affiliation: Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, NSW, Australia; Centre for Psychophysics, Psychophysiology & Psychopharmacology, University of Wollongong, NSW, Australia; University of Western Sydney, NSW, Australia.
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Gonsalvez
authors.affiliation: Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, NSW, Australia; Centre for Psychophysics, Psychophysiology & Psychopharmacology, University of Wollongong, NSW, Australia.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Johnstone
mesh_terms: D000328:Adult; D004569:Electroencephalography / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D016584:Panic Disorder / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D010775:Photic Stimulation / Q000379:methods; D065808:Prepulse Inhibition / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: Anxiety; Checkers; ERPs; Facilitation; OCD; Priming; Washers