Patients with lesions of the left hemisphere often suffer from oral-facial apraxia, apraxia of speech, and aphasia. In these patients, visual features often play a critical role in speech and language therapy, when pictured lip shapes or the therapist's visible mouth movements are used to facilitate speech production and articulation. This demands…

Researchers investigating the cerebral information processing of visual stimuli have usually followed the pattern of stimulating the subject's eyes with light and observing accompanying changes in brain wave patterns. Such visually evoked responses (VERs) have been found to discriminate bright from dull children and dyslexic from normal readers.…