title: Smoking withdrawal modulates right inferior frontal cortex but not presupplementary motor area activation during inhibitory control.
abstract: Smokers exhibit decrements in inhibitory control (IC) during withdrawal. The objective of this study was to investigate the neural basis of these effects in critical substrates of IC--right inferior frontal cortex (rIFC) and presupplementary motor area (pre-SMA). Smokers were scanned following smoking as usual and after 24-h smoking abstinence. During scanning they completed a Go/No-Go task that required inhibiting responses to infrequent STOP trials. Event-related brain activation in response to successfully inhibited STOP trials was evaluated in two regions of interest: rIFC (10 mm sphere, x=40, y=30, z=26) and pre-SMA (10 mm sphere, x=2, y=18, z=40). Smoking abstinence robustly increased errors of commission on STOP trials (37.1 vs 24.8% in the satiated condition, p<0.001) while having no effects on GO trial accuracy or reaction time (RT). In rIFC, smoking abstinence was associated with a significantly increased event-related BOLD signal (p=0.026). Pre-SMA was unaffected by smoking condition. The results of this preliminary study suggest that successful IC during withdrawal is associated with increased processing demands on a cortical center associated with attention to inhibitory signals.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA.
authors.forename: Rachel V
authors.initials: RV
authors.lastname: Kozink
authors.forename: Scott H
authors.initials: SH
authors.lastname: Kollins
authors.forename: F Joseph
authors.initials: FJ
authors.lastname: McClernon
mesh_terms: D000328:Adult; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*; D014029:Tobacco Use Disorder / Q000503:physiopathology*