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.