Comparing language samples of Bangla speakers using a colour photograph and a black‐and‐white line drawing

Abstract

Background A comprehensive aphasia assessment is necessary to diagnose the type and severity of aphasia differentially and guide appropriate interventions. One component of an aphasia assessment is the picture description task (PDT), designed to probe spontaneous speech fluency and information content. Most aphasia assessments use black‐and‐white line drawings (LD) to elicit spontaneous language samples from people with aphasia (PWA). However, recent studies reported two visuographic variables: (1) colour (over black and white) and (2) photograph (over LD), that tended to encourage easier and faster comprehension and increased overall naturalistic language production from neurologically healthy individuals as well as PWA. Additionally, a suitable stimulus for a PDT should always be culturally relevant to the target population. Therefore, we suggest that a new PDT must include a culturally appropriate colour photograph (CP). Aims To investigate if a culturally appropriate CP elicits longer and more complex utterances than a culturally appropriate black‐and‐white LD from neurologically healthy native Bangla speakers. Methods & Procedures A total of 30 participants (mean age = 36.03 years) were recruited based on self‐reports of no known impairments in cognition, language, vision and hearing. All were of middle socioeconomic status with at least 12 years of formal education. A culturally appropriate CP was selected showing multiple characters performing various functions. Later, an artist prepared the black‐and‐white LD of that CP. The elicited language samples using these two pictures were transcribed and coded following preset transcription and coding guidelines. The transcribed samples were further analysed using the Bangla adaptation of Systematic Analysis of Language Transcripts (SALT) software. To identify the differences in language production between these two picture types, investigators used four measurement variables: mean length of utterances (MLU), complexity index (CI), total number of words (TNW) and words per minute (WPM). Outcomes & Results Of the four measures, only MLU showed a statistically significant difference between the CP and the black‐and‐white LD. CI demonstrated a strong correlation with MLU for the CP, which indicates that the participants who produced higher MLU for the CP also produced a higher CI for the CP. There were no significant differences between the two picture types for CI, TNW and WPM. Conclusions & Implications This study found that the grammatical complexity, as measured by MLU, of spontaneous language production of neurologically healthy adults was higher when a CP was used in a PDT. A CP may also be beneficial for PWA to produce complex language samples.