In order to assess the impact of chronic alcohol misuse on basic Visual fun
ctions. we investigated motion perception. visual short-term memory, and vi
sual divided attention in recently detoxified patients and matched controls
by means of visual psychophysical tasks, subjects were tested twice within
the first 3 weeks of detoxification in order to assess the potential recov
ery of visual performance. Patients demonstrated significant impairments in
visual perception of coherent motion for slow, but not faster. speeds, and
in speed discrimination as assessed by random dot kinematograms. Visual sh
ort-term memory tested with a delayed vernier discrimination task. on the o
ther hand, was not significantly affected in patients. When processing hier
archical letters. a divided attention task, detoxified patients showed neit
her impairments in overall attentional capacity nor attentional allocation,
bur slightly enhanced interference of global information on local target p
rocessing. The results of the visual divided attention task contradict the
predictions of the 'right hemisphere' hypothesis of alcoholism: global targ
et information - mediated by the right hemisphere - was not only accessible
to detoxified patients, hut seemed to exert an even greater influence on l
ocal processing during early detoxification. than in matched controls. Limi
ted recovery within the first 3 weeks was seen only in visual speed discrim
ination. Recently detoxified patients revealed deficits similar to intoxica
ted social drinkers in identical tests of visual perception of motion, hut
not visual short-term memory.