FREE BOOKS

Author's List




PREV.   NEXT  
|<   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60  
61   62   63   64   65   >>  
re, and by this is meant the portion of brain which receives impressions from each half of the field of vision, is situated for the most part on the inner (unseen) surface of the occipital lobe. In front of the central fissure is situated the motor area, or that region destruction of which causes paralysis of the muscles moving the structures of the opposite half of the body. If the situations indicated by black dots be excited by an interrupted electric current, movements of the limbs, trunk, and face occur in the precise order shown, from the great toe to the larynx. In front of this precentral convolution are the three frontal convolutions, and it would seem that the functions of these convolutions are higher movements and attention in fixation of the eyes; moreover, in the lowest frontal region, indicated by fine dots, we have Broca's convolution, which is associated with motor speech; above at the base of the second middle frontal convolution is the portion of cortex in which is localised the function of writing. Taste and smell functions reside in brain cortex only a small portion of which can be seen, viz. that at the tip of the temporal lobe.] Muscles and groups of muscles on the two sides of the body which invariably act together may thus be innervated from either hemisphere, e.g. the muscles of the larynx, the trunk, and upper part of the face. Gall, the founder of the doctrine of Phrenology, wrecked his fame as a scientist by associating mental faculties with conditions of the skull instead of conditions of the brain beneath; nevertheless, he deserves the highest credit for his discoveries and deductions, for he was the first to point out that that part of the brain with which psychic processes are connected must be the cerebral hemispheres. He said, if we compare man with animals we find that the sensory functions of animals are much finer and more highly developed than in man; in man, on the other hand, we find intelligence much more highly developed than in animals. Upon comparing the corresponding anatomical conditions, we see, he said, that in animals the deeper situated parts of the brain are relatively more developed and the hemispheres less developed than in man; in man, the hemispheres so surpass in development those of animals that we can find no analogy. Gall therefore argued that we must consider the cerebral hemispheres to be the seat of the higher functions of the mind. We must moreover acknowl
PREV.   NEXT  
|<   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60  
61   62   63   64   65   >>  



Top keywords:

animals

 

developed

 

hemispheres

 

functions

 
conditions
 
convolution
 

muscles

 

frontal

 

portion

 

situated


movements

 

convolutions

 

larynx

 

cerebral

 

highly

 

higher

 

cortex

 
region
 

discoveries

 

deductions


processes
 
unseen
 

connected

 

psychic

 

credit

 

surface

 

scientist

 
wrecked
 

Phrenology

 

founder


doctrine

 
associating
 

mental

 
beneath
 

deserves

 

faculties

 
occipital
 
highest
 

surpass

 

development


analogy

 

acknowl

 

argued

 

deeper

 

impressions

 

receives

 
sensory
 

compare

 
comparing
 

anatomical