THE EXTENT to which brain injuries productive of sensory and motor aphasia preclude the effective use of subvocal language is imperfectly known. Since any attempt to test central functions must necessarily involve sensory and motor activity, it is extremely difficult to determine in aphasic persons whether deficits revealed by tests involve an incapacity for the subvocal use of language or reflect the loss of other skills required for the apprehension and execution of the task. Thus Head tended to emphasize central disorders of symbolic formulation, whereas Kinnier Wilson stated the belief that many of the symptoms Head described were apraxic or agnosic in character. It occurred to me that the problem of subvocal language in aphasic patients could profitably be investigated by studying speech patterns in their dreams. In this way it might be possible to determine what types of aphasia are accompanied with a disturbance of "inner speech."
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