DEVELOPMENTAL APHASIA: Also known as Congenital Word-blindness and sometimes referred to as Alexia or Dyslexia.

EDINBURGH T'HIS remarkable developmental failure is met with in various sensory-motor affections and may be manifested in functional failure in connection with sight, hearing, kinaesthetic performance and probably in other functional activities. We are here concerned with developmental aphasia connected with vision, also referred to as congenital word-blindness. This disability is met with in children but does not become obvious until the child has been confronted with the problem of learning to read. The condition does not depend on the degree of general intelligence but is met with in 'all grades of natural ability, including occasionally individuals of the highest intelligence, which renders it all the more important that the nature of the disability should be clearly recognised. It does not depend on failure of vision due to errors in refraction or difficulty in focusing, or other causes found in the eye, though such should always receive treatment when present. This condition is a failure in visual comprehension, caused by delayed development of unilateral hemispherical dominance and failure in word-memory and relates to the psychology of vision: letters and words are seen but not recognised. Fortunately aural perception is available and eagerly used by children suffering from this visual embarrassment and proves to be of great value to them. There is a natural tendency to recovery in all children so affected which increases progressively with the child's development and education. The condition may be mild and transitory or severe and difficult to overcome. The cases form a graded series, including all degrees of severity. In the milder cases recovery often takes place in the ordinary course of school education: in the more severe cases persistent skilled instruction, undertaken early, is essential. In the Edinburgh Primary Schools about 10 per cent. of the children were found to be affected by developmental aphasia, of whom half recovered in the ordinary course of school education, while the remainder required special treatment. Teachers of children may fail-to recognise the fundamental cause of the symptoms and this was appreciated by Hinshelwood in 1896 when he wrote: " It is a matter of the highest importance 522