The Research On Mechanism Of Frequency Effect In Patients With Chinese Aphasia

The purpose of this study was to observe the frequency effect influences on Chinese aphasics and analyze their mechanism in aphasia subjects.The research is divided into three parts.PartⅠ: For explore the frequency effect in patients with aphasia.Objective: To clarify the frequency effect exists in aphasia patients.Method: 11 patients with aphasia who met the criteria were collected.They have finished the naming task(through the picture to naming)for two times,which consisted of 15 low-frequency images and 15 high-frequency images.The response time and correct rate were collected and analyzed for determining the existence and strength of the frequency effect.Results: The Wilcoxon rank sum test was used for the date calculation.The average naming time of the high-frequency group was 78 ms faster than that of the low-frequency group in the first naming task,the difference was not significant statistically(p> 0.05).The average naming time of high-frequency group was 261 ms faster than that of low-frequency group in the second naming(p <0.05).The average accuracy rate of high-frequency group was 18% higher than low-frequency group in the first naming(p<0.05).The average accuracy rate of high frequency group was 17% higher than that of low frequency group in the second nomenclature(p <0.01).Conclusion: Frequency effect may occur in subjects with aphasia but unstable.Aphasia is also a factor that affects the frequency effect.PartⅡ: The frequency effect impact on participants with aphasia at the conceptual processing levelObjective: To divide the role of frequency effect from conceptual level to lexical semantic modules.Methods: 11 aphasia subjects who participated in the first part process the second part.They were asked to finish the pictorial identified task(through the picture to identify its character).The response time and correct rate were collected and analyzed for determining the existence and strength of the frequency effect.Results: The Wilcoxon rank sum test was used for the date calculation.The average response time of high frequency group was 21 ms faster than that of low frequency group(p> 0.05).In the judgment task,the average accuracy rate of high-frequency group was 3% lower than low-frequency group,the difference was not significant statistically(p> 0.05).Conclusion: In the aphasia subjects,the frequency effect impact on the conceptual level is unstable.This may be affected by a variety of factors such as aphasia,the location of brain impaired,and modules injured.PartⅢ: Researching the mechanism of frequency effect in the conceptual level and lexical level.Objective: Seek to study the location of frequency effect in normal subjects.Methods: 31 healthy subjects were enrolled in this study.The same tasks as the second part and the lexical identified task(through the word to identify its character)of the same corpus of the second part were performed.The response time and correct rate were collected and analyzed for determining the existence and strength of the frequency effect.Results: The average response time of the high-frequency group was 14 ms faster than that of the low-frequency group in the pictorial identified task,the difference was not significant statistically(p> 0.05).The average response time of high frequency group was 25 ms faster than that of low frequency group in the lexical identified task,the difference was significant statistically(p <0.01).Conclusion: While the non-speech task processed,the frequency effect plays a role in lexical-semantic representation,lexical selection and lexical level.The closer the lexical selection and the lexical level are,the greater the frequency effect.