NERVE 



173 



6. Auditory Centre in the Cortex Cerebri. 



Ferrier, by removing the superior temporo-sphenoidal lobe 

 in the monkey, produced no motor disturbance, but found 

 evidence of loss of hearing in the opposite ear. When the 

 region was stimulated, he found that the monkey pricked up 



BL. 



N.A< 



^ 



1«>«<^. 



G,M. 



N.vi 



S.YE. 



Oc.n. 



Fig. 86. — Connections of Cochlea with the Central Nervous System. Coch.R., 

 cochlear root of eighth nerve ; N.Acc., tuberculum acusticum and 

 nucleus accessorius sending fibres to the cerebrum (C.B.) and to the 

 oculo-motor mechanism (X. vi.) through the posterior coUiculi ; 

 C.B.L., cerebellum ; G.M., the corpus geniculatum mediale. 



its ears and looked to the opposite side, and he considered 

 that these observations prove the existence of a special 

 localised mechanism for the reception of stimuli from the ear. 



The receptor arrangements in the ear enables loudness 

 — amplitude of vibration ; pitch — rate of vibration ; and 



