Evening star., 1954-12-23
Hearing Mechanism
Found Highly Complex
Ability to Discriminate
Between Sounds Is Studied

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Hearing and the ability to make
fine determinations Of sound are conl-
plex beyond all previous concept. ex-
periments carried out under the Once
Of Naval Research reveal.
There are at least four discreet areas
In each temporal lobe Of the brain.
the portions OF the cerebral cortex just
above each ear. reports DR.. Archie r.
Tunturi Of the University Of Oregon.
who has carried out the experiments.
He worked with the uncovered brains
of dogs. These animals are known to
have an acute hearing sense, possibly
equal to that Of man at his best. He
] explored the dog cortex millimeter by
miliimeter with tiny electrodes which
responded to the electrical activity
aroused In the cortex by sounds trans
mitted through the ears.
The four areas themselves can DO
minutely subdivided by extremely fine
sound differences. DR.. Tunturi found.
The investigations are considered an
approach to the problem Of why ma
ture Is not Just hopeless tumble OF
Sounds problem Of special sigrlif-
icance to the Navy, operation Of some
Of whose devices requires extremely
fine determinations.
Big Field Ahead.
Thus far the investigation has pro-
ceeded only as far as the brains sound
reception apparatus. Still ahead lies
the exploration OF the correlation Of
sound with sights, memories, odors and
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scious action by the individual
Memory, Dr. Tunturi reports. Ii an
intriguing problem since there must
be some mechanism by which present
aspects Of q sound can be correlated
with past aspects of the same message
In order to make any sense.
Memory" the researcher says, ''is
basic to how the brain handles In
formation. We have uncovered Short
duration memories OF the order Of II
to $50 thousandths Of q second and
somewhat longer memories lasting up
to two seconds Attempts are being
made to investigate the long-term
memories which last from years to
decades.
"We wish to be able to predict what
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Of receiving an auditory communica-
ton to the time when we do sonle-
thing about It. Unless some clue Is re-
ceived as to how the brain handles
information, 1t will be necessary to add
electrical gadgets ad infinitum to in
struments."
The capacity Of nuclear radiation to
cause tumors in plants has Just been
reported by scientists Of the Brook
haven, Long Island, laboratory Of the
Atomic Energy Commission.
Plant tumors. 1t is stressed, cannot be
exactly correlated with malignant
growths Of animals, although they have
some characters In common and study
of one may throw light on the other.
Drs. Arnold Fl. Sparrow and Lloyd
A. Schairer worked with o particular
hybrid type Of tobacco which has q
normal tendency to produce non-fatal
tumors in mature plants. When exposed
to radiation such plants showed q
much greater tendency towards tumor
formation than did unirradiated speci-
mems. More than half the plant tissues
became humorous In plants receiving
heavy doses Of radiation over a mini
mum period Of about six weeks.
Such plants. the two scientists report.
develop the normal stem and leaves
and then become covered with gray
green tumor mass. This stiles the
normal tissues and the entire plant
withers and dies In few weeks.
The cause of tumor formation due
to irradiation is not known. according
to DR.. Sparrow Biologists theorize.
however, that 1t is due to physiological
disturbances, rather than to mutations
Of cells. the basis of heredity, which
may be the cause Of many animal
tumors.
The plant structure consists of two
types of cells. the biologists point out.
These are known as meristematic and
differentiated cells. The former are
simple in structure and have not
started to specialize. Differentiated
cells are those with special functions,
such as the formation Of stem. leaf
or root. They constantly are being
recruited from the undifferentiated
cells.
The moment normal meristematic
cell begins to specialize is decisive
one in its growth. It may change nor
mally or it may 60 wild Into the type
Of growth characteristic Of both plant
and animal tumors." Spontaneous plant
tumors apparently get started at this
stage.
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