There are a number of children, estimated at from 5 to 15 per cent of the American grade school population, boys outnumbering girls three to one, who, without any demonstrable evidence of structural damage to the central or peripheral nervous systems, have difficulty in dealing with stimuli on a symbolic level. These children are suffering from developmental language disorders (Brain, 1961; Chess, 1944), variously described as congenital language disorders or lags (Head, 1927), specific language disorders (Silver and Hagin, 1960), developmental aphasias or dysphasias, dyslexias, dysgraphias, and dyspraxias (Bender, 1958; Money, 1962), congenital auditory imperception (Weisenberg and McBride, 1935; Worster-Drought and Allen, 1929a, b), congenitally word-deaf (Weisenberg and McBride, 1935) or wordblind children (Hallgren, 1950; Morgan, 1896), strephosymbolic (Orton, 1937) or sinlingualism (Peacher, 1950). These children have certain characteristics in common: 1. There is a strong family history of language disturbance (Hallgren, 1950). 2. All have evidence that the neurophysiological organization, corresponding to cerebral dominance, is not fully established (Silver and Hagin, 1960). 3. All have specific perceptual problems in more than one perceptual area. These specific perceptual problems are characterized by difficulty in orientation in space and in time, so that there are errors in right-left orientation; disturbance in body image relative to orien-