On Fri, 13 Oct 2000, Goss, Bill wrote:
> Does anyone have a quick answer to this student question?
>
> " When you consume too much alcohol and close your eyes you feel dizzy.
> What causes this sensation and why does opening your eyes help to reduce
> this feeling?"
There's a great answer to this question, courtesy of one-time
TIPSter Don McBurney (who regrettably seems to have bailed out,
apparently no longer able to put up with some of our more inane
discussions).
In an old edition of his book _Introduction to
Sensation/Perception_ (1977, p. 177) and probably in newer
editions as well, he discusses the work of Canadian physiologist
and astronaut Ken Money (although I'm not sure if he actually
made it into space).
The usual thought is that the dizziness is a central nervous
system neural effect of the alcohol. Not so, according to Money
and Myles (1975). They used heavy water (like ordinary water but
just a tad heavier (duh!)). Subjects who drank it produced a type
of nystagmus (pattern of regular eye-flicks) when they tilted
their heads, a sign of stimulation of the vestibular (balance)
system. M & M explained this as due to the heavy water quickly
diffusing through the body, and into the cupula (the sensory
mechanism of the vestibular system), before it reached other
parts of the semicircular canals. Accoring to McBurney's summary,
"As a result, the cupula becomes heavier than the fluid in the
canal and therefore responds anomalously when the head is
tilted."
Heavy water isn't alcohol. Alcohol isn't heavy, it's light.
Alcohol also differentially diffuses into the cupula, but this
time it makes it lighter. The result is a nystagmus in the
opposite direction. Apparently M & M clinched the interpretation
by a mathematical analysis fully supported by their observations.
Bottom line: alcohol changes the mechanical action of the
peripheral apparatus which senses head tilt. So when you move
your head, you get dizzy. At this point McBurney makes a great
observation. He says you have a number of options to avoid
dizziness. You could mix your drinks with heavy water, and the
effects will cancel, but (in 1997) the amount of heavy water
needed would set you back about $10 per shot of whiskey. Or you
could keep your head still. Or you could not drink.
I'll drink to that.
Whoops! Almost forgot the tag question posed by Bill. Vestibular
sensations are strongly inhibited by vision, and most experiments
on the vestibular sense require the subject to be blindfolded. So
it's reasonable that you'd feel the anomalous effects of alcohol
more strongly when your eyes are closed.
-Stephen
Money, K., & Myles, W. (1975). Motion sickness and other
vestibulo-gastric illnesses. In: R. Naunton (Ed). The
vestibular system. Academic Press, pp. 371-77.
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Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470
Department of Psychology fax: (819) 822-9661
Bishop's University e-mail: [EMAIL PROTECTED]
Lennoxville, QC
J1M 1Z7
Canada Department web page at http://www.ubishops.ca/ccc/div/soc/psy
Check out TIPS listserv for teachers of psychology at:
http://www.frostburg.edu/dept/psyc/southerly/tips/
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