Spatial-frequency discrimination, brain lateralisation, and acute intake of alcohol.
The effect of alcohol (breath-alcohol level of 0.1%) on perceptual discrimination of low (1.5 cycles deg-1) and high (8 cycles deg-1) spatial frequencies in the left and right visual field was measured in eighteen right-handed males, in a double-blind, balanced placebo design. Discrimination thresholds for briefly (180 ms) presented sinusoidal gratings were determined by two-alternative forced-choice judgments with four interleaving psychophysical staircases providing random trial-to-trial variation of reference spatial frequency and visual field, in addition to a random (+/- 10%) jitter of reference spatial frequency. Alcohol produced overall higher discrimination thresholds but did not alter the visual-field balance: no main effect of visual field was observed, but in both placebo and alcohol conditions spatial frequency interacted with visual field in the direction predicted by the spatial-frequency hypothesis of hemispheric asymmetry in visual-information processing, with left-visual-field/right-hemisphere superiority in discrimination of low spatial frequencies and right-visual-field/left-hemisphere superiority in discrimination of high spatial frequencies.
Watten
R G
RG
National Institute for Alcohol and Drug Research, Oslo, Norway. reidulf.g.watten@sifa.no
Magnussen
S
S
Greenlee
M W
MW
D000328:Adult; D001921:Brain / Q000502:physiology*; D004192:Discrimination, Psychological / Q000187:drug effects; D004311:Double-Blind Method; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010919:Placebos; D012684:Sensory Thresholds / Q000187:drug effects; D013028:Space Perception / Q000187:drug effects*; D013998:Time Perception / Q000187:drug effects*
D010919:Placebos; D000431:Ethanol