An investigation of the incidence of apraxia and agnosia in the non-speech defective population.
The existence of apraxia and agnosia has been recognized for some years in the field of speech correction. An unpublished study by Wurth shows the incidence of lingual apraxia and agnosia in articulatory disorders. Palmer was the first to call attention to the existence of linguo-labial and lingue-alveolar apraxia and agnosia in articulatory problems. For a number of years Palmer had collected information regarding tongue function of cases with articulatory defects. He recorded signs of apraxia and agnosia in linguo-labial and linguo-alveolar function. These phenomena were studied by Wurth who collected information from case histories of children with an articulatory defect who showed signs of apraxia or agnosia without any overt indications of brain injury. Wurth sampled one thousand consecutive case histories of articulatory defects from the files of the Institute of Logopedics and reported that 84.3% of the subjects exhibited no evidence of apraxia or agnosia and 15.7% exhibited one or the other or both phenomena. Wurth did not study the possible incidence of these conditions in the normal population. The question immediately arises as to whether these phenomena are peculiar only to speech defective children. While in does not seem probable that “normal” speakers would have such signs, the lack of information indicates that a large sample of normal speaking children should be tested for agnosia and apraxia in order to establish this point.