Verbal Short-term memory deficit and its relation to language impairment in Cantonese speakers with aphasia

published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Relationship between deficits of verbal short-term memory and auditory impairment among Cantonese speakers with aphasia

Background Patients with left hemisphere stroke often have co-morbid verbal short-term memory (STM) and language impairment. Studies have indicated that treatment on STM deficits generally have positive effect on patients’ responses to language therapy (Murray, 2012). Chinese is a logographic language and lack grapheme-phoneme relationship as English or other alphabetic languages. Law, Yeung, and Chiu (2008) found that absence of grapheme-phoneme correspondence results in poor phonological awareness among Cantonese speakers. Chen, Cowell, Varley, and Wang (2009) also suggested that shorter articulation time for digits in spoken Mandarin accounts for higher digit spans than English. Aim This study aimed to investigate the relationship between STM and auditory linguistic tasks in Cantonese speakers with aphasia. Specifically, whether the models used in explaining the relationship between STM and language processes and if STM treatment approaches in English can be applied to non-alphabetic languages was discussed. Procedures Fifteen left hemispheric stroke participants and fifteen controls were assessed with a series of immediate serial recall (ISR) tasks, including monosyllabic high frequency non-words, monosyllabic low frequency non-words, disyllabic non-words, monosyllabic real words, disyllabic high imageability real words, disyllabic low imageability real words, and auditory linguistic tasks, including auditory discrimination, lexical decision, and auditory word recognition. The stroke group was also administered the Cantonese version of the Western Aphasia Battery (CAB). Results The results showed statistically significant difference in all ISR and auditory linguistic tasks between the stroke control groups using Mann-Whitney Test (p0.05) statistically significantly predicted comprehension score in CAB. Spearman’s rho showed moderate to high correlations between auditory discrimination and word recognition tasks with almost all ISR tasks (0.57 to 0.92, p≤0.05) but moderate correlation between lexical decision task with only one ISR task. Wilcoxon Signed Rank test found statistical significant difference between real words and non-words in both monosyllabic and disyllabic words (p<0.01) of the two groups. Discussion Our results suggested that Cantonese speakers demonstrated more difficulties in non-words and lexical decision tasks, potentially due to the additional linguistic factor of lexical tone (Cutler & Chen, 1997).The importance of lexical tone in phonological processing of tonal languages, which warrants further investigation, should be highlighted for clinical assessment as well as intervention

Verbal Short-Term Memory And Language Impairments In Cantonese Speakers After Stroke

Purpose: The study examined the relationship between verbal short-term memory (STM) and language impairment in Cantonese speakers after stroke. It is hypothesised that Cantonese speakers with left-hemisphere (LH) stroke would perform worse than those with right hemisphere (RH) stroke and normal controls. Specific linguistic factors of Cantonese might affect results in the tasks. Method: Fifteen participants with LH stroke, 10 with RH stroke and 25 healthy controls were tested with auditory–verbal immediate serial recall (ISR) tasks and auditory linguistic tasks. All stroke participants were assessed with the Cantonese version of Western Aphasia Battery (CAB). Result: The LH group performed significantly worse than the RH and healthy control groups in the auditory verbal ISR and auditory linguistic tasks. There were significant lexicality, frequency and imageability effects in most tasks. Auditory discrimination and word comprehension tasks, but not the auditory word recognition task had correlations with ISR tasks. Conclusion: Verbal STM and language performance of Cantonese-speakers with history of LH stroke were inferior to RH stroke and healthy controls. The effects of lexicality, word frequency and imageability on verbal STM memory performance were found. Cantonese tones have effects on performance in auditory word recognition task, similar to onset, nucleus and rime

Verbal short-term memory and language impairments in Cantonese speakers after stroke

Purpose: The study examined the relationship between verbal short-term memory (STM) and language impairment in Cantonese speakers after stroke. It is hypothesised that Cantonese speakers with left-hemisphere (LH) stroke would perform worse than those with right hemisphere (RH) stroke and normal controls. Specific linguistic factors of Cantonese might affect results in the tasks. Method: Fifteen participants with LH stroke, 10 with RH stroke and 25 healthy controls were tested with auditory–verbal immediate serial recall (ISR) tasks and auditory linguistic tasks. All stroke participants were assessed with the Cantonese version of Western Aphasia Battery (CAB). Result: The LH group performed significantly worse than the RH and healthy control groups in the auditory verbal ISR and auditory linguistic tasks. There were significant lexicality, frequency and imageability effects in most tasks. Auditory discrimination and word comprehension tasks, but not the auditory word recognition task had correlations with ISR tasks. Conclusion: Verbal STM and language performance of Cantonese-speakers with history of LH stroke were inferior to RH stroke and healthy controls. The effects of lexicality, word frequency and imageability on verbal STM memory performance were found. Cantonese tones have effects on performance in auditory word recognition task, similar to onset, nucleus and rime