Alcohol induced changes in regional cerebral glucose metabolic rate duringdivided attention

Under conditions of moderate alcohol intoxication (0.75 ml/kg) and an alcoh ol-disguised placebo, eight non-alcoholic male volunteers performed a divid ed attention task after injection of 18-F-2-fluoro-2-deoxyglucose (FDG) for a Positron Emission Tomography (PET) study. The administration of alcohol or placebo followed a random order double-blind protocol. During 32 min of divided attention, the subject performed a letter matching task or a spatia l orientation task presented simultaneously on a computer-generated split d isplay. The task to be pet-formed was indicated by an arrow on the display that changed randomly every few trials. Alcohol intoxication was associated with a trend toward generally reduced performance. Task performance differ ences between the alcohol and placebo conditions were significantly correla ted with cortical glucose metabolic rates (GMR) in the superior, inferior, and middle parietal lobes. Impaired performance was associated with GMR dec reases. GMR in several subcortical and medial cortical areas were also corr elated with performance changes, including areas of the putamen and cingula te. The major finding is that individual differences in GMR change from pla cebo to alcohol in parietal cortex are related to individual differences in attention performance. The application of PET with selective information p rocessing paradigms provides a useful method for isolating and in identifyi ng the effects of alcohol intoxication on the function of the central nervo us system. (C) 1999 Elsevier Science Ltd. All rights reserved.