The sun. [volume] (New York [N.Y.]) 1833-1916, 1882-04-09

has begun for the cerebral cell and the pow.r
Of retention Ia already on tho brink of decav.
New acquisitions OF heterogeneous clements
which did not form portion Of the circle Of
our youthful knowledge become difficult IL not
impossible. We know how painful tho labor Of
learning n foreign language. easy for tho
young child. proves to tho adult. and how
bunted even in the domain Of common things
appear our powers of application In general IL
We have to learn things that are quite new to
us. Finally. as tho human frame bnEins TO suf-
fer from tho effects ~ that scncsccnce which oc-
ours in different individuals at very differ
erent periods the cerebral cells. like the other
elements Of the organism. undergo icEcnera-
ton. They grow old histologicay: they be-
come moro o.. less innltrated with fatty granu-
lar matter they rca.>e to be Transparent, shrivel
up, and. from dynamic p Htnt OF Wow, insens-
bly, lose n portion of their seneibiity and
special rctentvc power. Regarded AZ loci OF
organic phos phorescence. they may be said to
be eXtinguishcl within certain cir'umscribed
localities OF the cerebral corteN, and conse-
quently cease to preserve record of their i'm
pressions. A strange phenomenon now occurs.
We pcrccivc-contrary to what would seem
most probable prior'-that in old people. as
In persons suffering from dementiu old memo-
ries remain tho freshest and most vivid, while
recent lactS anu Impressions Tec'Ncu ~ lue
present moment are unnotccd and treated as
IL they never reached the nervous centres DR..
Luys deems It probable that at this period Of
life the cells Of the sensorium altered in their
essential constitution have become lazy and
incapable of erecting themselves iii the pres
ence OF recent external impressions. and that
this state of torpidity toward new eNcitations
leaves the field free to the older ones which. no
longer obsoured by more lively improvements.
continue to vibrate without opposition, and
thus perpetual the last phosphorcscent CLEANS
Of a far-oT past which is dying.
".
The author next considers the special form
of the vitality of the nervous elements known
as automatic activity" which, takon in con-
junction with sensbity and organic phes-
phorcsence. constitute the fundamental ply
Biological factors Of mental action. The
phenomena of automatic nervous life reveal
themselves under their simplest ru1imentary
form in the mysterious operations of vegeta-
tive life. Passing to animal organisms. we find
automatic activity SO vivacious In the minute
structure OF the gray plexuses of the spinal
cord that 1t persists Of itself exercises itself
JnOtI prODr;o apart from all participation Of
the superior regions Of the encerhalon. Al
though indeed we should cut the spinal cords
OF living animals into separate seSmcnts. we
should discover that each segment would iso-
latcdy give rise to a series OF independent
motor phenomena The experiments Of Charles
Robin made upon the corpse of a dccapitated
criminal. have shown that the automatic ac-
tivities Of the spinal cord in man may continue
for time to exhibit undiminished energy and
| power of coordination in the form Of regularly
associated movements with definite object
| such as movements Of defence made by the hand
after a cutaneou5 notwithstanding these
with as much regularity as though the brain
had directed them.
| The automatic activity OF the nervous ele-
mcnts awakcs ut variable epochs. according TO
| the prccocity OF their morphologicil develop
mcnt. Thus the spinal axis being more rap
| idly developed than the brain in the regular
| evolution Of the nervous system, automatic
! manifestations may take place in it, even
| while they are very imperfectly developed in
the cerebral gray substance Childhood and
! youth are the two phases OF life during which
the automatic energy of the cerebral tissue
! reveals itself most strikingly. 1t Is largely by
| an automatic absorption of the impressions.
| which incessantly reverberate in all the re-
gions Of n child's sensorium that the external
| world pcnetrates into him. and that. by the I'M
| conscious evolution OF the specific energies of
| the brain cells. his mental development goes on
with the prodigous rapidity which eXcites our
! establishment. AS maturity approaches the
automatic activities Of the cells become gradu-
ally less intense. and the effects of progressive
! senility are marked by q slow embedding
| Of the automatic vigor OF the cerebral conf
ponents. That dcadening of the sensbty
| which betrays the complete satulation Of the
clements of the sensorium. and their inca
pacity for maintaining q condition Of crethism
takes more and more significant forms. The
| human brain experiences the need Of prolonged
repose; the ardor of the grand struggle for life
| irE nj A r,trn 10
ed from II great number Of social careers. Thus
it happens that the period of retirement and
inactivity which inevitably awaits each indi-
vidua as regards the part he has played on
the stage of life. physiologically Expresses the
| slow outwearing of the energies Of automatic
life which. by degrees. cease to vibrate and
betray. 10y their sackening the progressive
dulling of the srnsibility Of the cerebral cell.
V.
Such being the fundamental properties Of the
nervous elements. TO wit sensibility, organic
hosphorescence. and automatic activity. how
does DR.. Luys explain the consciousness Of
personal identity? In his view the notion Of
personality, which most psychologists regard
rs the simrlCs, Of presentations. is an cNtreme-
" complex product The elements II the vege-
tativo and sensitive sonsibility OF the living
organism enter primary factors into the
genesis Of the notion OF our personality. and
the effective participation OF the clements Of
the scnsorium completes and prrfccls it. What
we call the consciousness Of personal identity
is an intricate phenomenon which uulrr:ocs
developmcnt-a trne physiological process
which has its own mode OF origin. it, phases Of
evolution. it, manifold conditions OH which its
life and endurance depend and its moments Of
disturbance, du ring which il may br "''trs"d
and temporarily disappear. During the hrst
period Of an Infants life the notion ~ p"rson;
atty, is vague, indefinite, and IL, run(ured
rs tho organic machinery when produces
it. The ploNnsce of the sensorium are
scarcely formed. cerebral biologic d''rclqpmrnt
waits uron that the spinal aNi~ =" that tho
automatic life nj tho outset r"igns atone, II is
only little by lille. through Tho p' rir"ting Of
the sensorul ipparatuses and those Of the
cerebral activity that the infant comes to dis
tinguish his sensations TO see. To hear, and to
Keep y CONSCIOUS memory of impr'.- Ions per
r"ivcd. Hencctorth an inccs-aii' labor begins
ln5onsiHly in his mind; n natural selection
takes place in the mass OF the acquisitions no
makes and while all the impression, ydl!atInG
t from the sensitive regions Of his or.,gusm ara
n l,,.tt