Patterns of spontaneous speech impairment in dynamic aphasia

Organic brain damages often lead to speech disorders - aphasia (Bullier et al., 2020; Damasio, 1992). Luria’s classification (1962) describes dynamic aphasia, which is of particular interest for research. To date, it is known that dynamic aphasia is characterized by significantly impaired spontaneous speech and intact comprehension, repetition, and naming skills. How exactly spontaneous speech is impaired has not yet been described in detail. For this reason, the purpose of this study was to describe the linguistic patterns of spontaneous speech impairment in dynamic aphasia. The material for this study was spontaneous speech samples from patients with dynamic aphasia and subjects without speech disorders. Spontaneous speech samples were analyzed using quantitative production analysis (Saffran et al., 1989; Wilson, 2010). The Bayesian approach, which is used to compare a single case to an entire group, was used as a statistical method (Crawford & Garthwaite, 2007). The results of the analysis revealed disorders specific to dynamic aphasia. Thus, a decrease in the proportion of nouns and independent parts of speech distinguishes dynamic aphasia from efferent motor aphasia.