Alcohol dose effects on brain circuits during simulated driving: an fMRI study.
Driving while intoxicated remains a major public health hazard. Driving is a complex task involving simultaneous recruitment of multiple cognitive functions. The investigators studied the neural substrates of driving and their response to different blood alcohol concentrations (BACs), using functional magnetic resonance imaging (fMRI) and a virtual reality driving simulator. We used independent component analysis (ICA) to isolate spatially independent and temporally correlated driving-related brain circuits in 40 healthy, adult moderate social drinkers. Each subject received three individualized, separate single-blind doses of beverage alcohol to produce BACs of 0.05% (moderate), 0.10% (high), or 0% (placebo). 3 T fMRI scanning and continuous behavioral measurement occurred during simulated driving. Brain function was assessed and compared using both ICA and a conventional general linear model (GLM) analysis. ICA results replicated and significantly extended our previous 1.5T study (Calhoun et al. [2004a]: Neuropsychopharmacology 29:2097-2017). GLM analysis revealed significant dose-related functional differences, complementing ICA data. Driving behaviors including opposite white line crossings and mean speed independently demonstrated significant dose-dependent changes. Behavior-based factors also predicted a frontal-basal-temporal circuit to be functionally impaired with alcohol dosage across baseline scaled, good versus poorly performing drivers. We report neural correlates of driving behavior and found dose-related spatio-temporal disruptions in critical driving-associated regions including the superior, middle and orbito frontal gyri, anterior cingulate, primary/supplementary motor areas, basal ganglia, and cerebellum. Overall, results suggest that alcohol (especially at high doses) causes significant impairment of both driving behavior and brain functionality related to motor planning and control, goal directedness, error monitoring, and memory.
Meda
Shashwath A
SA
Olin Neuropsychiatry Research Center, Institute of Living at Hartford Hospital, Connecticut, USA. smeda01@harthosp.org
Calhoun
Vince D
VD
Astur
Robert S
RS
Turner
Beth M
BM
Ruopp
Kathryn
K
Pearlson
Godfrey D
GD
D000328:Adult; D000704:Analysis of Variance; D001334:Automobile Driving; D001921:Brain / Q000098:blood supply / Q000187:drug effects*; D001931:Brain Mapping; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003198:Computer Simulation; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009415:Nerve Net / Q000187:drug effects*; D010100:Oxygen / Q000097:blood; D025341:Principal Component Analysis; D011597:Psychomotor Performance / Q000187:drug effects; D016037:Single-Blind Method; D013997:Time Factors; D014584:User-Computer Interface; D055815:Young Adult
D002492:Central Nervous System Depressants; D000431:Ethanol; D010100:Oxygen