Prosodic skills in Spanish-speaking adolescents and young adults with Down syndrome

Abstract

Background: Down syndrome (DS) is a neurodevelopmental disorder of genetic origin with a cognitive-behavioural profile that distinguishes it from other syndromes. Within this profile, language difficulties are particularly marked, having been more studied in childhood than in adulthood. More generally, there is a paucity of research on the prosodic skills of individuals with DS, despite the relevance of this linguistic component for effective communication.

Aims: This study aimed to analyse, for the first time, the prosodic profile of Spanish-speaking teenagers and young adults with DS. We hypothesized that participants with DS would show significantly lower skills for the perception and production of prosodic functions and forms when compared to peers with intellectual disability (ID) of unknown origin. We also hypothesized that teenagers and young adults with DS would have better prosody perception than prosody production.

Methods & procedures: The final sample included in the study comprised 28 Spanish-speaking teenagers and young adults with DS and 29 teenagers and young adults with other ID matched on chronological age and nonverbal cognition. Their prosodic skills were tested by means of the Profiling Elements of Prosody for Speech and Communication battery. This battery allows for the separate evaluation of the comprehension and expression of the communicative functions of prosody and the discrimination and production of the forms that carry out such functions.

Outcomes & results: In the prosody function tasks, which are the most adaptive tasks for the communicative process, we found, as expected, significantly lower scores on the turn-end, chunking, and focus tasks in the group with DS. However, no significant between-group differences were found for the affect tasks. Participants with DS also had significantly lower scores on the prosodic form tasks than participants with other ID. The results of the comparison between prosodic perception and production skills showed that a generalization about a better profile in comprehension versus production is not possible and that there is a dependence on the demands of the prosodic task undertaken.

Conclusions & implications: The findings contribute to the ongoing development of the language profile of teenagers and young adults with DS and imply the need to design prosodic intervention programs based on their specific profile.

What this paper adds: What is already known on the subject Prosody is a fundamental element of language, and its mastery affects the effectiveness of communication. However, research on prosody in Down syndrome (DS) that offers a holistic view from a psycholinguistic approach is still scarce. To date, studies focused on providing a detailed profile of prosodic skills in individuals with DS have been mainly conducted with a few English-speaking children. These studies have shown that the comprehension and production of prosody is severely impaired, especially when considering affect and focus production, as well as the perception and production of prosodic forms. During childhood, greater efficacy is found in prosody comprehension than in prosody expression. What this study adds This is the first study analysing the prosodic profile of a large group of Spanish-speaking teenagers and young adults with DS. Poorer performance in the perception and production of both prosodic functions and forms was observed in participants with DS compared to participants with intellectual disability of unknown origin matched on chronological age and nonverbal cognition. Unlike what has been previously found in children, teenagers and young adults with DS performed at the same level as the control group on the understanding and expression of affect through prosodic cues. Results also showed that a generalization about a better prosody profile in comprehension versus production is not possible. What are the clinical implications of this work? This study provides new data on the prosodic skills of Spanish-speaking teenagers and young adults with DS. Given the impact of prosody on effective communication and the pattern of difficulties found in this study, speech and language therapists working with individuals with DS should consider including prosodic skills in interventions not only in childhood but also in adolescence and adulthood. Therefore, the prosodic profile of strengths and weaknesses in individuals with DS found in this research has direct implications for clinical practice.

Keywords: Down syndrome; Spanish; clinical assessment; intellectual disability; prosody.