Alcohol and visual performance

1. The authors examined the effect of acute alcohol consumption on a set of visual tasks: visual short term memory, depth perception, and attention. 2. In a repeated measurement design, thirteen subjects performed the tasks once sober and once intoxicated with 0.8 g/kg body weight pure ethanol in o range juice (33% alcohol). Subjects underwent a neuropsychological (Benton test) and a psychophysical test (vernier discrimination) both assessing vis ual short term memory, the test d2 as a measure of attention and concentrat ion, and a psychophysical depth perception task. 3. Subjects demonstrated significant alcohol-related impairments in depth p erception and in visual short term memory as assessed by the vernier discri mination task. However, the neuropsychological Benton test and test d2 fail ed to reveal alcohol-related changes in performance - probably due to super imposed learning effects. Performance was neither correlated with blood alc ohol levels (BAL) nor perceived intoxication. Even though the current BAL w as known to the subjects, only half of them demonstrated a close correlatio n between BAL and perceived intoxication.