title: Take it or leave it: prefrontal control in recreational cocaine users.
abstract: Though stimulant drugs such as cocaine are considered highly addictive, some individuals report recreational use over long periods without developing dependence. Difficulties in response inhibition have been hypothesized to contribute to dependence, but previous studies investigating response inhibition in recreational cocaine users have reported conflicting results. Performance on a stop-signal task was examined in 24 recreational cocaine users and 32 healthy non-drug using control participants matched for age, gender and verbal intelligence during functional magnetic resonance imaging scanning. The two groups were further matched on traumatic childhood histories and the absence of family histories of addiction. Results revealed that recreational cocaine users did not significantly differ from controls on any index of task performance, including response execution and stop-signal reaction time, with the latter averaging 198 ms in both groups. Functional magnetic resonance imaging analyses indicated that, compared with controls, stopping in the recreational users was associated with increased activation in the pre-supplementary motor area but not the right inferior frontal cortex. Thus, findings imply intact response inhibition abilities in recreational cocaine users, though the distinct pattern of accompanying activation suggests increased recruitment of brain areas implicated in response inhibition. This increased recruitment could be attributed to compensatory mechanisms that enable preserved cognitive control in this group, possibly relating to their hypothetical resilience to stimulant drug dependence. Such overactivation, alternatively, may be attributable to prolonged cocaine use leading to neuroplastic adaptations.
authors.affiliation: 1] Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Cambridge, UK [2] Department of Psychology, University of Cambridge, Cambridge, UK [3] Department of Psychology, Anglia Ruskin University, Cambridge, UK.
authors.forename: S
authors.initials: S
authors.lastname: Morein-Zamir
authors.affiliation: 1] Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Cambridge, UK [2] Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors.forename: P
authors.initials: P
authors.lastname: Simon Jones
authors.affiliation: 1] Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Cambridge, UK [2] Department of Psychiatry, University of Cambridge, Cambridge, UK [3] Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, UK [4] Clinical Unit Cambridge, GlaxoSmithKline, Addenbrooke's Centre for Clinical Investigations, Cambridge, UK.
authors.forename: E T
authors.initials: ET
authors.lastname: Bullmore
authors.affiliation: 1] Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Cambridge, UK [2] Department of Psychology, University of Cambridge, Cambridge, UK.
authors.forename: T W
authors.initials: TW
authors.lastname: Robbins
authors.affiliation: 1] Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Cambridge, UK [2] Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors.forename: K D
authors.initials: KD
authors.lastname: Ersche
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology; D016022:Case-Control Studies; D000697:Central Nervous System Stimulants; D003042:Cocaine; D019970:Cocaine-Related Disorders / Q000503:physiopathology / Q000523:psychology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D059907:Functional Neuroimaging; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011930:Reaction Time; D013647:Task Performance and Analysis; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D003042:Cocaine