Reading and writing disturbances due to Wernicke's area lesion

A study was made on reading and writing disturbances in two cases which showed typical Wernicke aphasia due to lesion in the Wernicke's area (left-posterior superior temporal gyrus). Examinations of reading-aloud and dictation were carried out concerning single Kanji characters which are supposed to be learned in 1 st to 3 rd grades at primary school, multiple Kana letters corresponding to single Kanji, and single Kana. The results showed better reading-aloud than dictation for both Kanji and Kana examinations in each of the two cases. Many errors were observed as phonemes of erroneous characters or letters similar to those of the subject character or letter (correct character or letter) in both the reading-aloud and dictation examinations of Kanji and Kana. Results suggest that “selection disturbances of phonemes” and “hearing-sense processing disturbances of phonemes,” which are characteristics of spoken language seen in Wernicke aphasia, are also seen in the written language. In the dictation of single Kana, both cases showed a similar tendency, and responses were observed in many cases where the correct letter was written but with addition of extra letters (additional response). The additional response in dictation is considered to be influence of “fluent talkative tendency,” a characteristic of spoken language seen in Wernicke aphasia.