Alcohol Intoxication Effects on Simulated Driving: Exploring Alcohol-Dose Effects on Brain Activation Using Functional MRI

Abstract

Driving while intoxicated is a major public health problem. We investigated impaired driving using a simulated driving skill game that presents an 'in-car' view of a road and a readout of speed. We explored brain activation and behavioral alterations from baseline at two blood alcohol concentrations (BACs). Participants received single-blind individualized doses of beverage alcohol designed to produce blood alcohol content (BAC) of 0.04 and 0.08 or placebo. Scanning occurred on a 1.5 Tesla Philips MRI scanner after training to asymptote performance. Analysis was performed using independent component analysis (ICA) to isolate systematically nonoverlapping 'networks' and their time courses. Imaging results revealed seven separate driving-related brain networks with different time courses. Several significant findings were observed for the imaging data. First, dose-dependent functional magnetic resonance imaging (fMRI) changes were revealed in orbitofrontal (OF) and motor (but not cerebellar) regions; visual and medial frontal regions were unaffected. Second, cerebellar regions were significantly associated with driving behavior in a dose-dependent manner. Finally, a global disruptive effect of alcohol on the ICA time courses was observed with highly significant differences in OF and motor regions. Alcohol thus demonstrated some behavioral effects and unique, disruptive, dose-dependent effects on fMRI signal within several brain circuits. The fMRI data also suggest that the deficits observed in alcohol intoxication may be modulated primarily through OF/anterior cingulate, motor and cerebellar regions as opposed to attentional areas in frontoparietal cortex.

Toward discovery science of human brain function

“…S1). Similarly, a data-driven, temporal concatenation ICA approach, combined with dual regression (32)(33)(34), revealed consistent patterns of functional connectivity across centers for 20 spatially independent functional networks ( Fig. 1 and Figs.…”

Independent components in stimulus-related BOLD signals and estimation of the underlying neural responses

“…Such nonlinear transient components of the BOLD response are well-known for cognitive tasks (Courtney et al, 1997;Postle, Zarahn and D'Esposito, 2000;Konishi, Donaldson and Buckner, 2001;Posse et al, 2001;Huettel, Guzeldere, McCarthy, 2001;Shulman et al, 2001;Zacks et al, 2001;Calhoun et al, 2001Calhoun et al, , 2002ad'Avossa, Shulman and Corbetta, 2003;Krasnow et al, 2003;Calhoun et al, 2004a;Cabeza et al, 2004;Chen and Desmond, 2005;Fox et al, 2005;Meegan and Honsberger, 2005;Scheibe et al, 2006;Vuilleumier et al, 2005) but we are not aware of reports of such transient responses the offset of repeated or steady-state stimulation. In either case, the rectifying nonlinearity of a positive response to both stimulus onsets and offsets goes far beyond any nonlinear properties of the hemodynamic models per se, and implies the operation of a pronounced (rectifying) nonlinearity in the underlying neural response to these stimulation conditions.…”

“…However, studies of multiple different response waveforms (Zacks et al, 2001;d'Avossa et al, 2003;Bellgowan et al, 2003;Calhoun et al, 2004a;Fox et al, 2005) have typically identified different cortical regions with differential response dynamics to the same or different stimulus conditions. The issue of multiple components within a given region of cortex is not addressed in these studies.…”

“…In most cases, it is assumed that the HRF incorporates both the cortical response to the stimulus and the hemodynamic response of the blood to the oxygen requirements of the cortical response. However, the situation may be much more complicated, with multiple components of neural response to the stimulus weighted differentially across the cortex (Zacks et al, 2001;d'Avossa et al, 2003;Bellgowan et al, 2003;Calhoun et al, 2004a;Fox et al, 2005), such that any one voxel contains contributions from more than one neural time course. If these time course variations are small relative to the BOLD temporal resolution, they may be negligible for an overall analysis of response strength, but the cited studies show non-negligible variations that require a more detailed analysis.…”

Alcohol Badly Affects Eye Movements Linked to Steering, Providing for Automatic in-Car Detection of Drink Driving

“…Altered cerebellar activity was associated in a dose-dependent way with impaired driving behavior (Calhoun et al, 2004;Carvalho et al, 2006). Altered cerebellar activity probably disrupts the coordination of eye movements with the actions involved in driving, including steering, just as it disrupts coordination of eye movements and steering on foot, or visually guided stepping, to targets (Crowdy and Marple-Horvat, 2004).…”