title: Acute effects of cocaine and cannabis on response inhibition in humans: an ERP investigation.
abstract: Substance abuse has often been associated with alterations in response inhibition in humans. Not much research has examined how the acute effects of drugs modify the neurophysiological correlates of response inhibition, or how these effects interact with individual variation in trait levels of impulsivity and novelty seeking. This study investigated the effects of cocaine and cannabis on behavioural and event-related potential (ERP) correlates of response inhibition in 38 healthy drug using volunteers. A double-blind placebo-controlled randomized three-way crossover design was used. All subjects completed a standard Go/NoGo task after administration of the drugs. Compared with a placebo, cocaine yielded improved accuracy, quicker reaction times and an increased prefrontal NoGo-P3 ERP. Cannabis produced opposing results; slower reaction times, impaired accuracy and a reduction in the amplitude of the prefrontal NoGo-P3. Cannabis in addition decreased the amplitude of the parietally recorded P3, while cocaine did not affect this. Neither drugs specifically affected the N2 component, suggesting that pre-motor response inhibitory processes remain unaffected. Neither trait impulsivity nor novelty seeking interacted with drug-induced effects on measures of response inhibition. We conclude that acute drug effects on response inhibition seem to be specific to the later, evaluative stages of response inhibition. The acute effects of cannabis appeared less specific to response inhibition than those of cocaine. Together, the results show that the behavioural effects on response inhibition are reflected in electrophysiological correlates. This study did not support a substantial role of vulnerability personality traits in the acute intoxication stage.
authors.affiliation: Department of Psychiatry, Radboud University Medical Centre, Nijmegen, The Netherlands. desireespronk@gmail.com.|Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands. desireespronk@gmail.com.
authors.forename: Desirée B
authors.initials: DB
authors.lastname: Spronk
authors.affiliation: Department of Clinical Psychology, Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.
authors.forename: Ellen R A
authors.initials: ER
authors.lastname: De Bruijn
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Janelle H P
authors.initials: JH
authors.lastname: van Wel
authors.affiliation: Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
authors.forename: Johannes G
authors.initials: JG
authors.lastname: Ramaekers
authors.affiliation: Department of Psychiatry, Radboud University Medical Centre, Nijmegen, The Netherlands.|Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.|Pompestichting for Forensic Psychiatry, Nijmegen, The Netherlands.
authors.forename: Robbert J
authors.initials: RJ
authors.lastname: Verkes
mesh_terms: D000328:Adult; D002188:Cannabis; D003042:Cocaine / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005071:Evoked Potentials / Q000187:drug effects*; D005106:Exploratory Behavior / Q000187:drug effects*; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000187:drug effects*; D007266:Inhibition, Psychological; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time; D055815:Young Adult
chemical_list: D003042:Cocaine
keywords: Cannabis; ERP; N2; P3; cocaine; impulsivity; novelty seeking; response inhibition