Affective prosody disorders in adults with neurological conditions: A scoping review

Background: Individuals with affective-prosodic deficits have difficulty understanding or expressing emotions and attitudes through prosody. Affective prosody disorders can occur in multiple neurological conditions, but the limited knowledge about the clinical groups prone to deficits complicates their identification in clinical settings. Additionally, the nature of the disturbance underlying affective prosody disorder observed in different neurological conditions remains poorly understood.

Aims: To bridge these knowledge gaps and provide relevant information to speech-language pathologists for the management of affective prosody disorders, this study provides an overview of research findings on affective-prosodic deficits in adults with neurological conditions by answering two questions: (1) Which clinical groups present with acquired affective prosodic impairments following brain damage? (2) Which aspects of affective prosody comprehension and production are negatively affected in these neurological conditions?

Methods & procedures: We conducted a scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. A literature search was undertaken in five electronic databases (MEDLINE, PsycINFO, EMBASE, CINAHL and Linguistics, and Language Behavior Abstracts) to identify primary studies reporting affective prosody disorders in adults with neurological impairments. We extracted data on clinical groups and characterised their deficits based on the assessment task used.

Outcomes & results: The review of 98 studies identified affective-prosodic deficits in 17 neurological conditions. The task paradigms typically used in affective prosody research (discrimination, recognition, cross-modal integration, production on request, imitation and spontaneous production) do not target the processes underlying affective prosody comprehension and production. Therefore, based on the current state of knowledge, it is not possible to establish the level of processing at which impairment occurs in clinical groups. Nevertheless, deficits in the comprehension of affective prosody are observed in 14 clinical groups (mainly recognition deficits) and deficits in the production of affective prosody (either on request or spontaneously) in 10 clinical groups. Neurological conditions and types of deficits that have not been investigated in many studies are highlighted.

Conclusions & implications: The aim of this scoping review was to provide an overview on acquired affective prosody disorders and to identify gaps in knowledge that warrant further investigation. Deficits in the comprehension or production of affective prosody are common to numerous clinical groups with various neurological conditions. However, the underlying cause of affective prosody disorders across them is still unknown. Future studies should implement standardised assessment methods with specific tasks based on a cognitive model to identify the underlying deficits of affective prosody disorders.

What this paper adds: What is already known on the subject What is already known on the subjectAffective prosody is used to share emotions and attitudes through speech and plays a fundamental role in communication and social interactions. Affective prosody disorders can occur in various neurological conditions, but the limited knowledge about the clinical groups prone to affective-prosodic deficits and about the characteristics of different phenotypes of affective prosody disorders complicates their identification in clinical settings. Distinct abilities underlying the comprehension and production of affective prosody can be selectively impaired by brain damage, but the nature of the disturbance underlying affective prosody disorders in different neurological conditions remains unclear. What this study adds Affective-prosodic deficits are reported in 17 neurological conditions, despite being recognised as a core feature of the clinical profile in only a few of them. The assessment tasks typically used in affective prosody research do not provide accurate information about the specific neurocognitive processes impaired in the comprehension or production of affective prosody. Future studies should implement assessment methods based on a cognitive approach to identify underlying deficits. The assessment of cognitive/executive dysfunctions, motor speech impairment and aphasia might be important for distinguishing primary affective prosodic dysfunctions from those secondarily impacting affective prosody. What are the potential clinical implications of this study? Raising awareness about the possible presence of affective-prosodic disorders in numerous clinical groups will facilitate their recognition by speech-language pathologists and, consequently, their management in clinical settings. A comprehensive assessment covering multiple affective-prosodic skills could highlight specific aspects of affective prosody that warrant clinical intervention.