Investigating the Effects of Rhythm and Entrainment on Fluency in People With Aphasia

Not Applicable

Completed

Conditions: Apraxia of Speech
Aphasia

Interventions: Behavioral: Unison speech (vs. solo)

Registration Number: NCT05248295

Lead Sponsor: MGH Institute of Health Professions

Brief Summary: Speaking in unison with another person is included as a part of many treatment approaches for aphasia. It is not well understood why and how this technique works. One goal of this study is to determine who benefits from speaking in unison, and what characteristics of speech are most helpful. Another goal is to investigate a possible mechanism for this benefit: why does speaking in unison help? A possible mechanism for this benefit is examined, by testing whether the degree of alignment of a person's speech with that of another speaker can account for unison benefit.

Detailed Description: Aphasia is an acquired language disorder, most commonly due to stroke. It can affect an individual's ability to speak, understand spoken language, read, and write. Many treatments designed to improve spoken language in persons with aphasia (PWAs) use unison speech, having the person with aphasia speak along with the clinician or with a recording. One goal of this study is to determine who benefits from speaking in unison, and what characteristics of speech help them the most. Another goal is to investigate a possible mechanism for this benefit: why does speaking in unison help? This knowledge is important because understanding who benefits from this commonly used and potentially powerful therapy component, under which conditions they benefit, and why they do, is critical for customizing therapy so it can be as effective and efficient as possible. Unison speech is conducted using one of two different timing patterns: (1) a natural conversational pattern, which is used in everyday conversations, or (2) a metrical pattern, which follows a beat-based timing framework, as in songs or some poems. In either case, precisely aligning one's speech with that of another person (i.e., entraining one's speech) requires prediction: each speaker must plan their own speech motor commands before having heard the other speaker say the words they are planning. Natural conversational timing requires the speaker to make use of knowledge about language, particularly grammar, to align with the other person. In contrast, a metrical pattern allows a speaker to predict speech timing without relying heavily on language-based knowledge. Given that many PWAs have impaired grammar, we hypothesize that most PWAs will benefit more from speaking in unison to sentences with metrical vs. conversational timing patterns. However, there is great variation in linguistic, motor speech, and timing skills across PWAs, so metrical and conversational timing patterns are likely to have different degrees of effectiveness for different individuals. Results from this study will demonstrate how individual characteristics and speech timing affect whether or not a person with aphasia benefits from speaking in unison. Results will also indicate whether a speaker's ability to predict speech timing is necessary for a benefit of unison speech. Prediction ability will be measured by how closely the speaker aligns their speech with a spoken model.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 100

Inclusion Criteria

Native-speaker fluency in American English (prior to stroke for people with aphasia)
Controls must report no history of speech, language, neurological disorders, or stroke
People with aphasia must be at least 6-months post-stroke, and aphasia must be due to stroke

Exclusion Criteria

Inadequate hearing ability to reliably complete task: fail hearing screen
Inadequate cognitive ability to understand and remember task: fail cognition screening (different measures for controls and people with aphasia)
Inadequate speech repetition ability to complete task, or to be considered a control: fail speech repetition screening (different thresholds for controls and people with aphasia)
Inadequate auditory comprehension ability to understand task: fail auditory comprehension screen (people with aphasia only)

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Intervention	Unison speech (vs. solo)	All participants will repeat sentences under four speech conditions, in a 2x2 design

Primary Outcome Measures

Name	Time	Method
Percent Syllables Correct	1 day study visit	The percentage of syllables correctly repeated from the target sentences will be computed for each contrast, Unison vs. Solo and Metrical vs. Conversational, capturing all 4 conditions in the 2x2 design (Unison Metrical, Unison Conversational, Solo Metrical, Solo Conversational). A protocol will be used to score syllables for correctness.

Secondary Outcome Measures

Name	Time	Method
Mean Syllable Offset From Model	1 day study visit	Of the syllables attempted by the participant, the mean offset from the corresponding target syllable in the model is computed for each syllable for each participant using the formula (p - d) - s, where p is the timing of voicing onset in the participant response, d is the timing of voicing onset in the model, and s is the line delay in the audio equipment. Means are computed for each participant and each condition. Note this measure can only be computed in the Unison conditions (Unison Metrical and Unison Conversational), since the Solo conditions do not have a simultaneous spoken model to which the participant is trying to align their speech.