Chinese word processing in nonfluent aphasic patients.

Background: Chinese nonfluent aphasic patients experience apparent speech production deficit, but it remains less known in which part of Chinese speech production this deficit occurs. The present study aimed to examine the ability of nonfluent aphasic patients in Chinese orthography, phonological and semantic processing via two experiments. Experiment I disclosed the general pattern of deficit of Chinese nonfluent aphasic patients in speech production. Experiment II tested whether this deficit occurs in orthography, phonological or semantic processing.

Methods: The present study adopted neuropsychological testing methods to compare speech production and Chinese word processing between nonfluent aphasic patients (the patient group) and normal individuals (the control group). Character reading and word reading tasks were used to test speech production. Chinese radical decision, rhyme decision and semantic decision tasks were used to examine word processing. Reaction time and the correct answer rate were collected.

Results: The patient group had a longer reaction time and was more prone to errors in both character reading and word reading tasks than was the control group. For the patient group, there was no difference between the reaction time of character reading and word reading, the error rate of the former was higher than the latter. In radical decision task the reaction time and error rate to the radical "mu " were higher in the patient group than in the control group. In the rhyme decision task, the reaction time and error rate to the rhyme "ang" were higher for the aphasic patients. In the semantic decision task the reaction time to characters in the category of animals was higher for the aphasic patients, yet the error rate was not significantly different between the two groups.

Conclusions: Nonfluent aphasic patients seemingly have decreased speed of speech production and an increased error rate. There is a deficit in phonological processing of aphasic patients while their semantic processing may remain intact.