Evening star. [volume] (Washington, D.C.) 1854-1972, 1936-10-30
Mysterious Brain Impulses
May Proue Development Index
Scientists Attending Child Research!
Society Meeting Discuss Waves From
Vision and Body Centers.
BY THOMAS r. HENRY.

BY THOMAS r. HENRY.
Mysterious brain waves"-minute
electrical impulses of the cerebral
cortex of the brain-may provide SCI
ence with q new index Of human
development.
Changes Of these waves with age
were described before the American
Society for Research in Child De-
velopment, meeting here today, by Drs.
Hallowell Davis of Harvard Universe
ty and Donald B. Lindsey of Western
Reserve University.
They are still very much in the
dark as to the meaning Of the phe-
nomenon which has been studied in
tensively in physiological laboratories
for the past two years. It Is as II
the brain was trying to send out q
message Of some kind which cannot
be decided The waves were first
discovered in Europe about four years
ago and are detected by placing cleo
trodes on the outside Of the skull
and greatly magnifying the impulses.
They seem to arise. the PSYCHOLOGISTS
reported today, directly out Of the
brain cortex itself and to be asso-
ciated in some mysterious way with
the maturing Of the brain. When
their meaning Is learned, it Is hoped,
they will prove a valuable aid in edu-
cation, so that eventually every child
will have an encephalogram taken
upon entering school.
Identical Twin Patterns Same.
DR.. Davis presented evidence that
the characteristic patterns may be
transmitted in some way by heredity.
He has found, he said that in identi-
cal twins who have absolutely the
same hereditary characters the wave
patterns are identical.
The principal report was made by
DR.. Lindsey, who for the past year
has been conducting a large-scale ex-
pertinent on their manifestations.
There are two sets Of these cleo
tricM impulses-the alphas and the
betas. The alphas are found chiefly
over the visual cortex, that part of
the back of the brain where Is located
the center of seeing. They have an
amplitude of from 80 to $50 millionths
OF a volt, and the waves recur about
10 times a second. The betas are
more prominent over the front of
the brain and especially over that
area Of the cortex concerned with
bodily movements They range from
20 to rs millionths of a volt and
frequency Of from 20 to so q second.
Dr. Lindsey studied the alpha waves
In 81 adults and 100 children from
] month to is years old. In the
adults, he found, the electrical pat
tern Of the visual cortex was remark
ably constant for the individual from
day to day. For different persons
the rate was from to IL a second.
A person could be identified by the
alpha awave pattern. 1t constituted
q sort Of brain fingerprinting.
The waves were most apparent
when the eyes were closed and the
mind vacant If light was flashed
in the eyes the waves disappeared in
about three-fifths of a second and
did not return until one or two sec
onds after the light was turned OF.
This finding may have some philo-
sophical significance In connection
with after images-the tendency to
see q luminous object for q second
or two after it has left the field Of
vision. During sleep or under anes-
thetics the waves disappeared except
for occasional volleys.
Frequency Steadily Increases.
With the children, DR.. Lindsey
found, the waves did not appear at
all until after the third month. Be-
tween the third and sixth months
they appeared but only at the rate
OF three or four a second. The rate
increased gradually until. between
the tenth and twelfth year, it was
faster than In adults. BY the six
tenth year it struck the adult level.
1t Is noteworthy, DR.. Lindsey
stressed, that the time Of life dur
Ing which the waves first appear,
Just after the third month, Is also
the time when a child Is first able
actually to perceive objects and to
follow a moving object with the eye
across a visual field. This is the
dawn of actual human seeing" when
the visual cortex Of the brain really
comes into action.
DR.. Lindsey and his associates are
trying to associate these individual
brain-wave patterns with personality,
temperament and physical growth.
There Is reason to believe, he said.
that they may be associated with such
qualities as attention and emotion.
Differences in Training.
Curious differences between boy
and man in response to exercise were
reported by DR.. r. E. johnson Of
Harvard University.
II trained man runs 100 yards
there is only slight increase in his
pulse rate and of Tactic acid, the prod