FREE BOOKS

Author's List




PREV.   NEXT  
|<   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  
>>  
e of movement of tongue) and the "cheiro-kinaesthetic" (sense of movement of hand) centres. Now a person may become hemiplegic and lose his speech owing either to the blood clotting in a diseased vessel, or to detachment of a small clot from the heart, which, swept into the circulation, may plug one of the arteries of the brain. The arteries branch and supply different regions, consequently a limited portion of the great brain may undergo destruction, giving rise to certain localising symptoms, according to the situation of the area which has been deprived of its blood supply. Upon the death of the patient, a correlation of the symptoms observed during life and the loss of brain substance found at the _post-mortem_ examination has enabled neurologists to associate certain parts of the brain surface with certain functions; but M. Marie very rightly says: None of the older observations by Broca and others can be accepted because they were not examined by methods which would reveal the extent of the damage; the only cases which should be considered as scientifically reliable are those in which a careful examination by sections and microscopic investigation have determined how far subcortical structures and systems of fibres uniting various parts of the cortex in the speech zone have been damaged. Marie maintains that the speech zone cannot be separated into these several centres, and that destruction of Broca's convolution does not cause loss of speech (_vide_ figs. 16, 17). There are at present two camps--those who maintain the older views of precise cortical centres, and those who follow Marie and insist upon a revision. Herbert Spencer says that "our intellectual operations are indeed mostly confined to the auditory feelings as integrated into words and the visual feelings as integrated into ideas of objects, their relations and their motions." Stricker by introspection and concentration of attention upon his own speech-production came to the conclusion that the primary revival of words was by the feeling of movements of the muscles of articulation; but there is a fallacy here, for the more the attention is concentrated upon any mental process the more is the expressive side brought into prominence in consciousness. This can be explained by the fact that there is in consequence of attention an increased outflow of innervation currents to special lower executive centres, thence to the muscles, but every change of tens
PREV.   NEXT  
|<   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:

speech

 

centres

 
attention
 

feelings

 
examination
 

integrated

 

destruction

 

muscles

 

supply

 

symptoms


arteries

 
movement
 

Herbert

 

Spencer

 
separated
 
damaged
 
operations
 

cortex

 

maintains

 
intellectual

revision
 

cortical

 

follow

 

precise

 
insist
 
present
 

maintain

 

convolution

 

concentration

 

consciousness


explained
 

consequence

 

prominence

 

brought

 

mental

 

process

 

expressive

 

increased

 

change

 
executive

outflow

 
innervation
 
currents
 

special

 

concentrated

 
Stricker
 

motions

 
introspection
 

relations

 
objects