title: Behavioral regulation in methamphetamine abusers: an fMRI study.
abstract: The goal of this study was to extend our previous findings of abnormal prefrontal function in methamphetamine (MA) abusers and controls and to link the imaging data to behavioral, demographic and drug use variables. We used a fast event-related functional magnetic resonance imaging (fMRI) design to examine trial-to-trial reaction time (RT) adjustments in 30 MA abusers and 30 controls. A variant of the Stroop task was employed to measure influence of response conflict on RT, including the level of trial-to-trial RT adjustments seen after conflict trials. Compared to control subjects, MA abusers exhibited reduced RT adjustments and reduced activation in the prefrontal cortex (PFC) after conflict trials. RT adjustment correlated negatively with PFC brain activity in the MA group, while a trend for a positive correlation was observed in controls. No correlations were observed between task performance or brain activity and age, education or drug use variables. These data support our previous findings that the ability to adapt a behavioral response based on prior experience is compromised in MA abusers. Interestingly, these impairments do not appear to be linked to drug use patterns or to educational levels.
authors.affiliation: Deparment of Psychiatry and Behavioral Sciences, University of California, Davis, CA, USA. resalo@ucdavis.edu
authors.forename: Ruth
authors.initials: R
authors.lastname: Salo
authors.forename: Catherine
authors.initials: C
authors.lastname: Fassbender
authors.forename: Michael H
authors.initials: MH
authors.lastname: Buonocore
authors.forename: Stefan
authors.initials: S
authors.lastname: Ursu
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000473:pathology* / Q000503:physiopathology*; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply* / Q000473:pathology; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology*; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D010100:Oxygen