Wernicke's and global aphasia without alexia
K. M. Heilman, L. Rothi, D. Campanella and S. Wolfson
It has been proposed that the comprehension of written language requires
transcoding from the visual (grapheme) to the auditory (phoneme). It has
also been proposed that visual word images can be comprehended without
grapheme-phoneme transcoding. We describe three aphasic patients with left
hemisphere impairment who had poor speech comprehension but could
comprehend written language. One of these patients had a subsequent right
hemisphere lesion and lost his ability to read. We propose that the right
hemisphere in some individuals may be capable of extracting semantic
information from iconic images (ideogram) without phonological processing.