Functional predictors for communicative and participatory aspects in speech sound disorders (apraxia of speech, aphasic phonological disorders)

• Applicant: Dr. Ingrid Aichert
• Subject Area: General and Comparative Linguistics, Experimental Linguistics, Typology, Non-European Languages
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 439064826

Over the last decades, aphasia research has developed a strong focus on the consequences of aphasia for communication in daily life, but only little is known about how a patient’s personal limitations are related to the specific pattern of her/his functional impairment. Moreover, despite the fact that sound production impairments (apraxia of speech, aphasic-phonological disorders) in aphasia may have a strong and very specific impact on participation, investigations into these conditions have so far largely been confined to the phonetic and phonological symptoms and their underlying mechanisms. This project strives to close this research gap by investigating how the symptoms of phonetic/phonological impairment may, in the context of other linguistic signs of aphasia, impact the patients’ abilities to communicate. The approach taken here is innovative to the extent that it investigates how laypersons, i.e., the patients’ potential communication partners, perceive aphasic speech. Laypersons’ evaluations of how a patient speaks are considered to be at the core of the patient’s limitations in communicating with the environment. Since their perceptions of aphasic output are expected to differ in many ways from expert-based linguistic assessments, this new approach promises valuable insights into how aphasic speech and language deficits may constrain participation in aphasia.The following specific goals will be pursued: (1) We will develop and evaluate new methods for the investigation of communication-related parameters based on the perception of laypersons. On the one hand, we will examine how aphasics’ utterances are perceived on a “proximal” level, i.e., how intelligible they are, whether they sound unnatural, and how efficient they are in conveying a message. On the other hand, we will also assess, on a more “distal” level of perception, the attributions and attitudes listeners implicitly derive from the speech output of aphasic patients, especially regarding their cognition, their emotions and behaviors, as well as their personality and social life.(2) The study will include analyses of speech and language symptoms across a broad range of dimensions, i.e., articulation, prosody, voice/respiration and lexicon/syntax, and will investigate how these symptoms influence the proximal and distal parameters of laypersons’ perceptions of aphasic and apraxic speech. (3) Moreover, we will investigate whether parameters of apraxic speech (i.e., the presence of prosodic impairments and symptoms of increased speech effort) have a specific impact on listeners’ perceptions. The project will thereby reveal whether apraxic speakers suffer in particular ways from negative attitudes and unfavorable evaluations of their speech by naive listeners.

• DFG Programme: Research Grants