Effects of ethanol on kinaesthetic perception.
In normal subjects, alcohol increases handwriting size, but the mechanism is not understood. Here we show that the alcohol effect on handwriting can be explained by a selective impairment of kinaesthetic perception. Thirty volunteers (15 male, aged 18-29 years) took part in an open study. They were tested before and after a drink containing vodka intended to produce a blood alcohol concentration of about 80mg/100ml. Tests included kinaesthetic distance estimation, in which volunteers worked with preferred hand and arm behind a screen which hid their movements; visual distance estimation; and measures of handwriting and drawing. Blood alcohol concentration at 55min, based on breathalyser measurements, was 76.7mg/100ml (SD 9.8). When asked to move the hand and mark a distance of 10cm from a starting point, distances estimates increased by 7-10% (p 0.01). Similar increases were seen for writing words and drawing characters. Signatures were increased in height but not in length. Distances estimated visually were increased much less, by 3-4% (p 0.05). Tests of psychomotor performance indicated the expected effects of ethanol. These results suggest that ethanol affects writing size by reducing kinaesthetically perceived distances.
Tiplady
Brian
B
Department of Psychology, University of Edinburgh, Edinburgh, UK. brian@penscreen.com
Baird
Robin
R
Lütcke
Henry
H
Drummond
Gordon
G
Wright
Peter
P
D000293:Adolescent; D000328:Adult; D004215:Distance Perception / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D006236:Handwriting; D006801:Humans; D007699:Kinesthesis / Q000187:drug effects*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D011434:Proprioception / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D012858:Size Perception / Q000187:drug effects
D000431:Ethanol