THE CEREBRUM 605 



imitate or reproduce the sounds of objects, words, letters, etc. (speech) or 

 to imitate or reproduce the visual impressions by verbal signs (writing) . 



For both spoken and written language two phases of activity are to be 

 recognized, viz.: a receptive or sensor and an emissive or motor, 

 i. The Receptive or Sensor Phase. Before language can be acquired by 

 a developing child, impressions of external objects must be made on the 

 visual, auditory and other sense-organs as well, which .in consequence 

 lead to the development in the associated cortical areas of sensations 

 and ultimately of conceptions regarding the nature of the objects im- 

 pressing themselves on the peripheral sense-organs. 

 Visual Sensations and Conceptions. Through the visual apparatus 

 in its entirety, sensations and definite concrete conceptions regarding 

 the shape, size, color, etc., of an object or word, letters and numbers, 

 etc., are obtained. For future use the sensations must not only be per- 

 ceived but registered or memorized. The memorization of the sensations 

 produced by luminous objects, is supposed to be associated with the 

 activities of the cortex on the lateral aspect of the occipital lobe; the 

 sensations produced by words, letters, and numbers with the activities 

 of the cortex of the supra-marginal and angular convolutions of the parietal 

 lobe. This is made possible by means of associations fibers which unite 

 the primary visual area in and around the cuneus, with the secondary 

 visual areas. That the visual memories are associated with the previously 

 mentioned convolutions of the parietal and occipital lobes is apparent 

 from the fact, that if they are destroyed by disease there is a loss of these 

 memories even though the individual sees the objects as formerly; but 

 though seeing them they cannot be remembered or recalled. To this 

 condition the terms word and object blindness have been given. 



Auditory Sensations and Conceptions. Through the auditory appa- 

 ratus in its entirety the child receives, coincidently with the development 

 of visual sensations and their memorization, sensations and definite 

 concrete conceptions regarding the intensity, pitch and timbre or quality 

 of sounds produced by atmospheric vibrations, due to vibrating bodies; 

 also sounds which are subsequently associated with the vocal and articu- 

 lating apparatus of human beings when pronouncing words, letters and. 

 numbers, or with objects such as bells, musical instruments, etc. For 

 future use the sensations thus aroused must not only be perceived but like- 

 wise registered or memorized. The memorization of the sensations pro- 

 duced by atmospheric vibrations is supposed to be associated with the 

 activities of the temporal lobe and more particularly of the posterior two- 

 thirds of the super-temporal and medi-temporal convolutions. This is made 

 possible by means of association fibers which unite the primary auditory area 

 with the secondary auditory areas. That the auditory memories are associ- 

 ated with the previously mentioned convolutions is apparent from the fact 

 that if they are destroyed by disease, there is a loss of these memories 

 even though the individual hears the sounds as formerly but though hear- 

 ing them, they cannot be remembered or recalled. To this condition the 

 terms word deafness and object deafness have been given. 



From the concrete conceptions formed of individual objects of a similar 

 character or of a class, there are developed abstract conceptions, by the 

 uniting into a single idea the elements which are common to all the objects 



