Evening star., 1936-03-27
BRAIN FLOW CAUSE.
Of CONSCIOUSNESS.
AWareness Is Traced to
Electric Balance
in Brain.
BY THOMAS r. HENRY.

Consciousness, unique attribute Of
animal life, appears to depend upon a
delicate electrical balance within the
nervous system.
Experiments supporting a galvanic
theory Of life's awareness of itself
were reported to the American Physi-
University of Illinois physiologists-
Drs. w. E. Burge, G. C. Wickwire and
w. P. Elhardt.
One side Of the balance is the cere-
bral cortex, the top" Of the brain
where the phenomenon Of conscious
ness is centered.
The other side is the rest of the
central nervous system which, is con-
tinually pouring into the cortex the
sensations Of which consciousness Is
composed.
Currents Over-Charged.
So long as the currents are flowing
toward the cortex the organism is
aware Of itself and its surroundings.
When the cortex becomes over
charged and the currents start flow-
ing the other way inconsistencies
results.
The University of Illinois expert
menters placed an electrode upon the
cortex OF deeply etherized dog by
removing a part Of the skull and an
other upon the exposed Sciatic nerve
Of the same animal. A delicate gall
vanometer was connected with the
electrodes. The cortex of the uncon-
scious animal was found to be clearly
To ha
was continuous flow of current from
the brain OF two or three micro
amperes.
The administration Of the ether
then was discontinued and the dog
allowed to regain consciousness. AS
the depths Of unawareness became
less and less the cOrtex became pro-
gressively less electro-positive. until
finally the current began flowing the
other way. BY the time the dog was
completely out of the anesthetic
there was a flow of two or three
micro-amperes from the sciatic nerve
to the brain The experimenters
found that this reversal could be
brought about as often as they pleased
by putting the same dog under ether
and bringing it out again.
Identical Results Found.
They found almost identical results
when the animal was rendered un-
conscious by bleeding or suffocation.
They reported: There seems to be q
threshold potential of the cortex
below which the animal loses con-
sciousness and above which it regains
consciousness. 1t is known that active
tissue is electromagnetic and inactive
tissue electro-positive. The electro
negative cortex is active and conscious,
while the electro positive cortex Is
inactive and unconscious.
Hence, it would seem, conscious
ness or Inconsistencies is matter
of electrical potential of the cerebral
cortex and this, in turn, IS undoubt-
edly dependent upon the balance be-
tween the loss and gain of electric
charges passing to and from the brain
over the nerves"
Assuming the validity of this theory
of consciousness. the Illinois physi-
ologists at once found a practical use
for it-objective measurement of the
depths of inconsistencies produced
by different aneSthetics. The deeper
the sleep" the higher should be the
electric potential of the cortex. They
tested the effects on dogs of ether,
nitrous oxide, ethylene gas and
chloroform.
In each case, they reported today,
as the depth Of the anesthesia in
creased there was a progressive de-
in, he nj
top OF the brain. Curiously enough,
however. only ether caused reversal
in polarity-that is, caused the cortex
to become electro-positive and the
sciatic nerve electro-nega egative. The
deepest anesthesia, apparently, was
produced by the ther-a conclusion
supported by other experiments.
Ether Best Anesthestic.
EITHER" they retorted, may be
considered the best of the anesthetics
used Most trouble was encountered
with chloroform, the anesthetic that
was supposed to produce the greatest
decrease in the negative potential of
the cortex. 1t did produce signifi-
cant decrease. but in addition it af-
fected the lower centers. In this re-
spect it may be considered the worst
of the four aneSthetics."
When person passes OUT from
too many highballs presumably 1t is
because the alcohol-a depressant OF
the higher nervous centers-has
tipped the electrical balance the
wrong way Such was the case when
the Illinois psychologists gave their
dogs large Intoxicating doses. When
they gave them enough, in fact, the
balance was reversed.
Much the same electric balance
mechanism may explain the cause Of
fatigue, according to another expert
ment reported by another group Of
University of Illinois Psychologists
associated with DR.. Burge-Drs. H. w.
Neild, H. NJ. Schamp and J. E. Sulli-
van.
They attached electrodes to an ex-
posed sciatic nerve of frog and to
one of the muscles which it served
In a rested state the current was
found to flow from the muscle to the
nerve with strength of one to two
micro amperes. Then the nerve was
stimulated over and over again with
delicate electrical shocks until the
muscle no longer contracted from the
stimuli-that is. until the nerve be-
came too weary" to function. When
this stage was reached the flow of
the current from muscle to nerve had
reached the point where it was almost
indistinguishable. although there
never was a complete reversal of
polarity.
The stimulating electrode then was
removed from the nerve and placed
on the muscle, which was stimulated
directly with the same kind Of gentle
shocks. until it no longer responded
to them. The direct stimulation of
the muscle, they reported, caused
still further decrease in the difference