Identifying a Culturally Appropriate Stimulus for the Bangla Picture Description Task

The absence of culture- and language-specific aphasia assessment in Bangla underscores a critical problem in Communication Sciences and Disorders. Aphasia occurs in ~41% of stroke survivors. Over 40 years, stroke incidence has doubled in the low- and middle-income countries, such as Bangladesh and India, where there are ~250 million native Bangla speakers. This study aimed to identify an appropriate picture stimulus for the Bangla Picture Description Task (PDT) intended for inclusion in a Bangla aphasia assessment. Researchers have reported the importance of cultural relevance and three visuographic variables of a picture, i.e., high-context, color, and photograph vs. black and white line drawing, for faster comprehension and comprehensive language production from people with aphasia and neurologically-healthy adults. The present study compared four culturally related and non-related picture stimuli with and without the three visuographic variables. This study used a repeated-measures crossover design to analyze spontaneous language samples from neurologically-healthy native Bangla speakers in three age groups (young 19-30, middle 40-55, and old 65-89 years) to identify any age-related language production changes Bangla speakers experience. Because a crossover design may generate carryover effects and thus influence a study’s findings, a linear mixed-effect (LME) model was used to identify the main effects in the presence of a possible carryover effect. Otherwise, a mixed multivariate analysis of variance (ANOVA) was used to determine the main effects. Moving-average type-token ratio (MATTR) was analyzed with mixed multivariate ANOVA. The LME model analyzed: 1) words per minute (WPM), 2) mean length of utterance in morphemes (MLU), and 3) total number of words. Finally, the complexity index (CI), a syntactic complexity measure, was analyzed with non-parametric tests because CI data was skewed. The study results demonstrated 1) a significant picture type effect for MATTR, WPM, and MLU, and 2) a significant age group effect for WPM, MLU, and CI. After combining the findings of all measurement variables for three age groups, the present study reports the culturally related high-context color photograph is the appropriate stimulus for the Bangla PDT. This study also indicates that older adults 65 years and above experience reduced fluency, grammatical complexity, and syntactic complexity