A PSYCHOLOGICAL INQUIKY INTO THE NATUEE OF 

 THE CONDITION KNOWN AS CONGENITAL WOBD- 

 BLINDNESS. 



BY LUCY G. FILDES. 



The aim of the investigation about to be described was to discover 

 something of the psychological characteristics of the condition commonly 

 called by the misleading term of congenital word-blindness — a condi- 

 tion which shows itself most clearly in the subjects' extreme difficulty, 

 or even total failure, in learning to read, and appears to be closely 

 related to the various forms of acquired alexia met with commonly as 

 the result of brain injury in later life. 



Three explanatory theories, it will be remembered, have been put 

 forward as indicating the nature and cause of this condition, viz. : — 



(1) A theory which assumes the existence of definitely localized and 

 circumscribed visual and auditory word-centres in the brain, the 

 destruction or isolation of which will destroy language in either its 

 visual or its auditory aspect ; 



(2) A theory which interprets word-blindness as only one symptom 

 in a general lowering of mental ability ; and 



(3) One which attributes the condition to a more specialized lowering 

 of power in the primary visual centres, rendering true visual percep- 

 tion of words and of other complex sense-data difficult. 



The main problems raised by these different interpretations are two 

 in number. Is inability to learn to read or the loss of the power of 

 reading due to specific or to general defect ? If the former, does the 

 defect show itself only in reading, or does there appear to be any 

 general lowering of visual power? A psychological investigation should 

 throw light on these points. 



The subjects mainly used for the investigation were twenty-six in 

 number — all children between the ages of 9 and 16 years, who were in 

 attendance either at ordinary elementary schools (4) or at special schools 

 for mentally defective children (22). They were selected on the report 

 of their teachers as finding reading a very great difficulty. Before the 

 work peculiar to the investigation was begun, all the children were 

 tested (a) with the Stanford revision of the Binet scale, in order to get 



