title: Amphetamine modulates human incentive processing.
abstract: Research suggests that psychostimulants can physiologically alter dopamine kinetics in the ventral striatum (VS) and psychologically enhance mood and attention. Using event-related functional magnetic resonance imaging (fMRI), we conducted a within-subject, double-blind, placebo (PLAC)-controlled study of the effects of oral dextroamphetamine (AMPH, 0.25 mg/kg) treatment on brain activity and affect during incentive processing. In two counterbalanced scanning sessions 60-180 min after ingesting AMPH or PLAC, 8 healthy volunteers played a game involving anticipation and receipt of monetary gains and losses. Group and volume of interest analyses suggested that by enhancing tonic over phasic activation, AMPH treatment "equalized" levels of VS activity and positive arousal during anticipation of both gain and loss. These findings suggest that therapeutic effects of amphetamine on incentive processing may involve reducing the difference between anticipation of gains and losses.
authors.affiliation: Department of Psychology, Stanford University, CA 94305, USA. knutson@psych.stanford.edu
authors.forename: Brian
authors.initials: B
authors.lastname: Knutson
authors.forename: James M
authors.initials: JM
authors.lastname: Bjork
authors.forename: Grace W
authors.initials: GW
authors.lastname: Fong
authors.forename: Daniel
authors.initials: D
authors.lastname: Hommer
authors.forename: Venkata S
authors.initials: VS
authors.lastname: Mattay
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Weinberger
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D005717:Games, Experimental; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000187:drug effects*; D009042:Motivation
chemical_list: D000697:Central Nervous System Stimulants; D003913:Dextroamphetamine