The morning news. [volume] (Savannah, Ga.) 1887-1900, 1893-07-06
coNPLKx1rr OF r14r BRAIN.
What Experiments Made Nowadays
Disclose.


From uarpers Magazine
When I was a student OF medicine,
thirty years ago, the brain was regarded
as single organ. and its various fmc-
tons were not thought 70 have any cs-
pecldI localized ceutors Of action. When
the brain acted 10 was thought that the
whole OF it acted, Just as the liver or the
stomach acts, as q whole. Now we know
that, instead OF the brain being a unit il
Is really a very complex organ. Besides
| the portions concerned in sight, smell,
/ thought, etc, we have four adjacent pOr-
lions which are concerned in motion.
One produces motion of the face; another,
| motion of the arms; third, motion of
! the legs and the fourth, motion of the
trunk.
How, it may be asked, have these facts
/ been determined Has il not been by OBJ
serving the effects of injuries and dis
| eases IN man2 To small extent, yes.
| But very, very rarely does q disease or in
jury involve only one of these very lin
tied regions of the brain, and the moment
two or more of them are involved, our in
| ferenCes become confused and mislead-
ing AS matter OF fact which cannot
be gainsaid, nine-tenths of our knowledge
has been derived from exact experiment
| upon animals, and in this way: A mon
Key is etheriZed, certain area of the
brain is exposed and an electric
current is applied. This stimula-
ton OF most portions of the brain
IS followed by no motion in any part of
the body. These parts of the brain, there
fore, have nothing to do with motion
but are the centers for general sensation
(touch), or for certain special senses, as
sight, hearing, etc, or for mental process
es. But in one definite region of the
Dram, called the motor area" the mo-
ment the brain is stimulated by the cleo
trlcal current, motion is produced, More
over, it was soon found that stimulating
different parts of this motor area produce
motion in different parts of the body, and
that this was not haphaZard, but that
stimulation of one part of it always pro-
duced motion in the arm, and in another
part motion in the leg, etc. Thus have
been mapped out the various portions of
the motor area.
1t is evident that by experiment upon
| animals the motor area can be more
easily and more exactly determined than
can those regions which are the seat of
the faculties of smell, taste, sight and
hearing, the presence or absence of thess
senses in animals being difficult to deter
mine with absolute accuracy. Still more
is this true of the parts of the brain
which have to do with mental process
Yet disease and injury in man, if they
alone could answer the questions what
part of the brain has to do with motion,
what part with sight, whatp part with the
intellect, ought to have answered them
long ago. No better evidence could
be given of the superb
GRITTY of experiment of animals over OBJ
| servation of accident and disease in man
in determining facts of this character than
this, that those centers are best and most
| accurately known which can be determin-
ed by vivisection, and that those in which
| vivisection can aid US but little are still
only vaguely located. Thus the motor
arear is positively and definitely located
| that for sight approximate taste and gen
eral sensation (touch) are still uncertain,
| though guessed at. AS to those for ment-
| al processes, except perhaps one, we are
almost wholly in the dark