HIGHER FUNCTIONS OP THE CEREBRUM IN MAN ; APHASIA 861 



forth of one memory impression is associated with others, and the child 

 comes to be able to associate the appearance or image of the bell with a 

 certain sound and with certain sensations of hardness, rotundity, etc. This 

 preliminary use of observation is known as perception. It involves the 

 fusion of direct sensations as well as their correlation with memory im- 

 pressions of former sensations. The number and variety of the latter 

 called into activity by a particular sensation will obviously vary at dif- 

 ferent times. On seeing a bell, for example, a child may associate it with 

 sound on one occasion, and on the next with the feeling of the bell. On 

 account of this difference in the detail of the method of association, it is 

 evident that perception must be a product of cerebral integration rather 

 than one depending on memory impressions stored in the isolated centers. 

 It is a complicated process with an infinite variety of possibilites as to the 

 exact way in which it is integrated on each occasion. 



The act of perception, however, becomes considerably simplified in the 

 higher animals by the laying down of short-cut paths of association. 

 These are formed first of all with the auditory center, in which the memory 

 impression of an articulated sound representing the object for example, 

 the word "bell" is stored away. The child comes to learn that this par- 

 ticular word is to be associated with the memory impressions it has stored 

 away of the sound, the sight, and the feeling of the bell. Similar short-cut 

 paths later become developed in connection with the visual centers, where 

 a certain symbol, like the word "bell," is presented to the child as signi- 

 fying all the other attributes of bell. In its most highly developed form, 

 therefore, perception may be described as the act of calling up one or 

 more sensorimemorial images when a name is seen or heard. 



Having acquired the ability to integrate sensorimemorial impressions 

 in the above described manner, the child next learns to integrate the motor 

 centers concerned in the control of the articulatory apparatus so as to 

 produce a sound. This sound is the word indicating the object involved 

 in the integrating process. It is the integration necessary to produce the 

 sound which symbolizes the particular object. 



When the power of understanding and producing language has been 

 acquired, the crowning process -of intellectual development the forma- 

 tion of a concept, or general notion becomes evolved. Thus, the evolu- 

 tion of a general name will include a number of particular objects or acts. 

 "This process of conception involves the revivification of numerous sen- 

 sorimemorial images which present common points of similarity" (Bol- 

 ton). It is relatively a simple process for such general objects as animal, 

 man, building, but becomes very complex for such abstract concepts as 

 heaviness, beauty, etc. It is obviously a process to which no one cerebral 



