Phonological Processing as a Predictor of Writing Ability in Bulgarian-Speaking Individuals with Aphasia

Aphasia, often resulting from a stroke, severely impairs communication, including written expression, limiting social participation and independence. This study explores the relationship between phonological processing and writing abilities in Bulgarian-speaking individuals with aphasia, aiming to identify key predictors for effective therapeutic interventions. Theoretical frameworks like the Parallel Distributed Processing (PDP) model and the Primary Systems Hypothesis (PSH) emphasize the interconnectedness of phonological, orthographic, and semantic systems, highlighting the critical role of phonological processing in writing performance. The study involved 30 individuals with motor and sensorimotor aphasia. Boston Diagnostic Aphasia Examination (BDAЕ) was used to assess writing abilities, while phonological processing was measured through the Bulgarian-adapted version of the Standardized Assessment of Phonology in Aphasia (SAPA), which consists of three subtests: reading ability (real words, pseudowords, pseudohomophones, non-standard words), auditory phonological processing (rhyming recognition – real and pseudowords, lexical decision, minimal pairs), and repetition, segmentation, and blending tasks (all with real and pseudowords) at the phoneme and syllable level. Results from the BDAE showed an average writing success rate of 40.69%, with significant variability (SD = 58.83). Basic automatic tasks, such as transcribing a name and address, were easier, while more complex tasks, such as story creation and dictation, posed substantial challenges. Phonological processing was found to be a significant predictor of writing ability, explaining 65.6% of the variance (F = 16.513; p = 0.000). The subtest focused on repetition, segmentation, and blending was the strongest predictor, explaining 84% of the variance in writing performance. Deficits were most pronounced in tasks involving segmentation of real and pseudowords, underscoring the critical role of phonological processing for writing accuracy and fluency. These results highlight the importance of integrating phonological processing assessments into diagnostic and therapeutic protocols for aphasia patients. Addressing specific phonological deficits can significantly improve written language outcomes, enhancing independence and quality of life for individuals with aphasia.