Evening star., 1895-01-12
BRAIN PHYSIOLOGY
FlechsfE's Intellectual Lfnk-A Re
marxnbIe Discovery.

FIechsig's Intellectual Link-A Re
marknbIe Discovery.
From the London Standard.
In the physiology of the brain step for
| ward has lately been taken which renders
the problem of intellectual activity con-
siderably more intelligible. The Leipsic
specialist for diseases of the mind, Prof.
F1echsig, at present director of the uni
versity, has lately discovered that within
| the surface of the cerebrum four connected
compIexes definahle, closely resembling
| one another, but essentially differing from
| the other parts of the cerebrum in ana
| tomical structure. These four centers lie
| in the fore part of the frontal cerebrum,
in the temporal lobe, in the hinder parietal
lobe, and in the Iobule. The extraordinary
development of these centers essentially
distinguishes the human brain from that
of the lower animals. Flechsig calls them
intellectual centers,'' or "centers of asso-
iation," because they concentrate the
activities OF the organs of sense into higher
units.
These centers do not exist in newborn
children. Not till months later, when all
the rest of the cerebral substance has be-
| come modulated, do these centers, with
which the child begins to think, develop.
The ''centers of association" are connected
by numerous systems of fberS. Flechsig
draws contrast between them and the
"centerS of sense" the centers of sight,
hearing, smell, touch, ETC., which produce
lower units. They receive the perceptions
which are conveyed to the brain by the
external organs of sense. In the centers
OF sense originates sensation 1t is only in
the centers Of association, however, with
which they are connected by innumerable
nerve hberS, that their contents are con-
verted into thoughts. The activity of the
centers of sense is directed outward; that is.
they receive the impulse to the exercise of
their functions from without. The centers
or association, on the other hand, only eS-
tablish the intellectual link between the
centers Of sense; they elaborate the i'm
preSSfonS OF the senses, their activity Is
directed wholly inward they are the bear
ers OF all that We call experience, knowl-
edge, cogniZance, principles and higher feel
ings, and also of language.
The importance of these centers appears
very clearly If we follow their DEVELOPMENT
in newborn children. When the inner de-
velopment of the centers of sense is COM
pleted after the third month the intellectual
centers begin gradually to form, and more
and more nerve fbers shoot forth from the
centers of sense into those new regions,
ending close to one another in the cerebral
corteX. Only about cne-third of the cere-
bral cortex is directly connected with those
nerve fbers. on which consciousness of
sensory Impressions depends; two-thirds of
the cerebral corteX have nothing 70 do
with this function. but serve the higher
purpose of the 'centerS of association"
The organ of the mind, says Flechsig dis
tinctly shows collegiate constitution; its
counsellorS are grouped in two senates, the
members of one of which bear names such
as sight, hearing, ETC., while those of the
others are called centers Of association.
The latter, however, are, like the former,
net of equal Importance In complicated
Intellectual work, indeed. they probably
work all four together, but pathological ex-
perience shows us that one center may be
Intact while another is disturbed; the Ian
guage, for instance, may be confused,
while the apprehension of the outer world
is not yet percep.ibly altered; or, on the
other hand, the language may seem cor
rect, whereas the conceptionS combine to
form utterly sensaless dclusions. The pow
er of expressing knowledge by language
evidently depends upon another center than
the power of grasping the natural connec-
ton of things. Mental diseases are caused
by the destruction of the centers of asso-
citation. Thus Flechsig has proved that So
called softening of the brain (dementia
paralytica) is restricted for the most part
to alterations in the intellectual regions,
and is caused by atrophy of the nerve
hbers. Therefore the thoughts get into
confused entanglement, the power OF re-
Numbering is lost, and the mind produces
new and strange images.