A Cantonese Linguistic Communication Measure for Evaluating Aphasic Narrative Production

This dissertation, "A Cantonese Linguistic Communication Measure for Evaluating Aphasic Narrative Production" by Pak-hin, Anthony, Kong, 江柏軒, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled A Cantonese Linguistic Communication Measure for Evaluating Aphasic Narrative Production Submitted by Anthony Pak-Hin Kong for the degree of Doctor of Philosophy at The University of Hong Kong In August 2006 This dissertation describes the development of a Cantonese linguistic communication measure (CLCM) to quantify narrative production of Cantonese aphasic speakers. Four new pictures containing local characteristics were developed, including revised pictures from the BDAE (Goodglass and Kaplan, 1993), the WAB (Kertesz, 1982) and its Cantonese version (Yiu, 1992), and a picture depicting a Chinese restaurant. The development of pictorial stimuli was motivated by the lack of culturally appropriate pictures for eliciting speech from Cantonese speakers. The CLCM contains eight indices reflecting the amount [Total number of words (NW), Number of informative words (IW)], efficiency [Index of Lexical Efficiency (ILE)], and rate of information conveyed [Index of Communication Efficiency (ICE)], the grammaticality [Index of Grammatical Support (IGS)] and extent of elaboration of sentences produced [Index of Elaboration (IEl)], as well as the degree of error 1production [Index of Error (IEr)] and lexical diversity [Index of Lexical Richness (ILR)] in the speech output. Chapter Two presented a pilot study of the CLCM. Preliminary normative data from 30 native Cantonese speakers were collected. Results of data from 10 Cantonese aphasic individuals revealed significant differences between normal and aphasic speakers on all indices, except for the NW. The four CLCM pictures were also found to be comparable in terms of their ability to elicit speech output from normal speakers. Chapter Three presented the main study where language samples from 60 aphasic and 73 normal speakers describing the CLCM pictures were collected. Again, apart form the NW, all CLCM indices could successfully discriminate aphasic (fluent as well as non-fluent) subjects from their controls. The IW, ICE, IGS, and ILR were found to consistently distinguish between fluent and non-fluent subjects. Both normal and aphasic speakers generally performed similarly across the four pictures. In addition, younger normal individuals tended to produce more informative words. In Chapter Four, the data in the main study were analyzed again using discriminant function analysis to see if combination of the CLCM indices could discriminate between the three subject groups as well as to predict group membership for each subject. While the IEr was found to be the most useful for 2distinguishing between aphasic and normal speakers, the ICE and IGS were found to be more important for discriminating between fluent from non-fluent aphasic subjects. In Chapter Five, the CLCM was examined on its ability to monitor changes of the narrative production of aphasic individuals over time during the period of spontaneous recovery as well as before and after receiving language interventions. It was found that the change of the CLCM indices was generally consistent with the expectations of recovery exhibited by aphasic speakers in acute stage post-stroke and the treatment outcomes for those receiving therapies. In conclusion, the CLCM is a reliable and valid measure for Cantonese aphasic narratives. Given the simplicity of its index computation, the product not only renders clinicians a