The Effect Of Working Memory On Chinese Speechreading For Students With Hearing Impairment

Due to hearing impairment(HI),students with HI are likely to use speechreading and sign language to attend social communication.As a main source of visual verbal perception,speechreading plays an important role in extracting visual speech information to afford speech recognition and language comprehension.Speechreading is a visual speech processing approach which integrates visual speech information through speech perception and creates abstract phonetic representation,then conducts syntactic and semantic analysis,so that speechreaders can complete language comprehension effectively.The spread of inclusive education,the enaction of communication curriculum standard in deaf school,and the need for students with HI to attend social communication,requires us to pay more attention to explore the potential cognitive mechanism of speechreading,and then to provide the speechreading training for students with HI with more efficient instruction.But the study on Chinese speechreading for students with HI is still at an early stage,the speechreading tests are inadequate,and most researches mainly predict the processing characteristics of Chinese speechreading from the aspect of participants’ variables,which pays less attention to exploring the cognitive processing mechanism of Chinese speechreading from the aspects of cognitive psychology.Therefore,this study will focus on the effect of working memory on Chinese speechreading for students with HI,adopting newly verified Chinese Speechreading Test.This study found that the working memory system for students with HI contains phonological loop,visual-spatial sketchpad,central executive system and episodic buffer,and the series of experimental tasks proved to be valid and effective to test the characteristics of working memory system for students with HI.Based on testing their working memory function,this study mainly explores the impact of working memory and its subsystem on Chinese speechreading abilities for students with HI.The aim of study 1 is to discover the function of phonological loop system in Chinese speechreading for students with HI,which can be divided into two sub-experiments to discover the effects of sub-components of phonological loop,the articulatory rehearsal system and phonological store,on Chinese speechreading.Results of study 1 found that the impacts of phonological loop on Chinese speechreading for students with HI mainly rely on the articulatory rehearsal system,while the phonological store did’t show significant function.Study 2 aims to discover the function of visual-spatial sketchpad on Chinese speechreading,which can be also separated to two sub-experiments to discover the effects of sub-components of visual-spatial sketchpad,spatial working memory and object working memory,on Chinese speechreading for students with HI.Results of study 2 found that neither spatial working memory nor object working memory affects Chinese speechreading abilities for students with HI,which indicated that visual-spatial sketchpad did not play an important role in Chinese speechreading.Study 3 explores the effect of central executive system on Chinese speechreading for students with HI via three sub-experiments,which reflects how the sub-functions of central executive system works in Chinese speechreading.Results indicated that there was only one sub-function of central executive,inhibition function,worked significantly in Chinese speechreading.The purpose of study 4 is to discover the effect of episodic buffer system on Chinese speechreading,which contains two sub-experiments to explore how the ability of integrated processing information and the ability of extracting information from long-term memory work in Chinese speechreading.This study found that both of the sub-functions of episodic buffer system played a significant role in Chinese speechreading.In addition,results also indicated that linguistic level had a significant effect on Chinese speechreading ability,which was manifested in that with the increase of linguistic level,the speechreading performance decreased.However,linguistic level has a strong limiting effect on high-level speechreading task,and a small limiting effect on the low-level speechreading tasks,such as words and phrase speechreading task.Based on what we had found above,this study discussed the working memory mechanism in Chinese speechreading for students with HI,and tried to construct a model of working memory system functioning in Chinese speechreading.From the model we can see that speech perception and speech encoding of silent visual verbal information are mainly carried out in phonological loop system,and then episodic buffer integrates and processes the spatial and verbal information from multiple channels,and conduct semantic extraction through two-way interaction with long-term memory so that complete the Chinese speechreading process.The central executive system can monitor and regulate the secondary processing system of working memory by inhibiting irrelevant information in speech perception,speech coding,and semantic extraction.Generally speaking,this model can be used to interpret the processing of speechreading in all three linguistic levels,but there are still some subtle differences when it comes to the function of sub-system of working memory on Chinese speechreading,which appears in the effect of articulatory rehearsal system,inhibition function of central executive system and the ability of integrated processing information.In conclusion,based on the impact of working memory on Chinese speechreading for students with HI,we provide some suggestions to improve the quality of Chinese speechreading training,including respecting the characteristics of their Chinese speechreading,paying more attention to develop working memory traing strategies,and integrating teaching materials,etc.What’s more,some areas related to further Chinese speechreading cognitive study are discussed.