On May 22, 1:07*am, Stealth Pilot
wrote:
On Wed, 21 May 2008 03:33:18 -0700 (PDT), More_Flaps

wrote:
On May 21, 9:59*pm, Stealth Pilot
wrote:
On Tue, 20 May 2008 19:00:25 -0700 (PDT), More_Flaps

wrote:
On May 21, 12:56*am, Stealth Pilot
wrote:

you need to learn about somatogravic thresholds, the effect of alcohol
on the viscosity of the fluids of the inner ear

How much alcohol are we talking about here? Dies the viscosity of the
endolymph actually change?


yes. you can be quite sober and still have the viscosity reduction
active in your ears some 48 hours or more later.
never, never, never drink alcohol in the week before flying IFR.

do some serious human factors reading. the subject is fascinating.
our human sensations have some amazing limitations.

if you need a good introductory text on human physiology to get some
underlying understanding I can recommend 'Human Anatomy and
Physiology' by Elaine N Marieb. It is published by Pearson Benjamin
Cummings in san francisco. excellent!

I've got several physiology/toxicology text books but I can't see a
reference to _viscosity_ changes in endolymph with alcohol. Are you
sure you mean viscosity and not density?

Cheers

I mean exactly what I wrote.

human factors stuff is reasonably new. it is probable that the
research in the human factors work doesnt make it into the other text
books because it is fairly specialised.
btw I dont quote human factors books because I was taught this stuff
in my commercial pilot studies. it is standard modern australian
commercial level aviation knowledge.


Hmm. As fas as viscosity changes go, gravitational sensing does not
require movement of endolymph. A small change in viscosity of
endolymph due to alcohol (EtOH) is not likely to do much except
_reduce_ rotational accleration sensation a little. There are no
scientific papers describing this effect as far as I know, just my
prediction based on how the labarynth works. The change in density of
the endolymph is the real problem as it affects the buoyancy of
cupula. Research has shown that this buoyancy hypothesis can explain
most of effects (e.g. PAN I & II) but there are additional central
effects due to nueronal signal processing that appears degraded by
EfOH. So in summary, if your testbook (a basic book targeted to nurses
and sports scientists) says "viscosity" it is probably either a typo
or factual error, cross it out and replace it with density and the
descrition of the buoyancy effects of EtOH .The reason why I asked you
to check on your claim of viscosity effects was that I had not heard
of this before.

Here's a relevant paper for you:

New insights into positional alcohol nystagmus using three-dimensional
eye-movement analysis.
Fetter M, Haslwanter T, Bork M, Dichgans J.Ann Neurol. 1999 Feb;45(2):
216-23.

Hope this helps with your studies and teaching human factors.

Cheers





the otoreports of this to my knowlege. HoViscosity of the endolymph is
not lilely to be a problem as it does not affect rotait is the density
chnage that leads to