Dataset Information

Examining cortical tracking of the speech envelope in post-stroke aphasia.

ABSTRACT:

Introduction

People with aphasia have been shown to benefit from rhythmic elements for language production during aphasia rehabilitation. However, it is unknown whether rhythmic processing is associated with such benefits. Cortical tracking of the speech envelope (CTenv) may provide a measure of encoding of speech rhythmic properties and serve as a predictor of candidacy for rhythm-based aphasia interventions.

Methods

Electroencephalography was used to capture electrophysiological responses while Spanish speakers with aphasia (n = 9) listened to a continuous speech narrative (audiobook). The Temporal Response Function was used to estimate CTenv in the delta (associated with word- and phrase-level properties), theta (syllable-level properties), and alpha bands (attention-related properties). CTenv estimates were used to predict aphasia severity, performance in rhythmic perception and production tasks, and treatment response in a sentence-level rhythm-based intervention.

Results

CTenv in delta and theta, but not alpha, predicted aphasia severity. Neither CTenv in delta, alpha, or theta bands predicted performance in rhythmic perception or production tasks. Some evidence supported that CTenv in theta could predict sentence-level learning in aphasia, but alpha and delta did not.

Conclusion

CTenv of the syllable-level properties was relatively preserved in individuals with less language impairment. In contrast, higher encoding of word- and phrase-level properties was relatively impaired and was predictive of more severe language impairments. CTenv and treatment response to sentence-level rhythm-based interventions need to be further investigated.

SUBMITTER: Quique YM

PROVIDER: S-EPMC10538638 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Examining cortical tracking of the speech envelope in post-stroke aphasia.

Quique Yina M YM Gnanateja G Nike GN Dickey Michael Walsh MW Evans William S WS Chandrasekaran Bharath B

Frontiers in human neuroscience 20230914

<h4>Introduction</h4>People with aphasia have been shown to benefit from rhythmic elements for language <i>production</i> during aphasia rehabilitation. However, it is unknown whether rhythmic processing is associated with such benefits. Cortical tracking of the speech envelope (CTenv) may provide a measure of encoding of speech rhythmic properties and serve as a predictor of candidacy for rhythm-based aphasia interventions.<h4>Methods</h4>Electroencephalography was used to capture electrophysio ...[more]

PMID: 37780966

Similar Datasets

Project description:After a stroke, approximately one-third of patients suffer from aphasia, a language disorder that impairs communication ability. Behavioural tests are the current standard to detect aphasia, but they are time-consuming, have limited ecological validity and require active patient cooperation. To address these limitations, we tested the potential of EEG-based neural envelope tracking of natural speech. The technique investigates the neural response to the temporal envelope of speech, which is critical for speech understanding by encompassing cues for detecting and segmenting linguistic units (e.g. phrases, words and phonemes). We recorded EEG from 26 individuals with aphasia in the chronic phase after stroke (>6 months post-stroke) and 22 healthy controls while they listened to a 25-min story. We quantified neural envelope tracking in a broadband frequency range as well as in the delta, theta, alpha, beta and gamma frequency bands using mutual information analyses. Besides group differences in neural tracking measures, we also tested its suitability for detecting aphasia at the individual level using a support vector machine classifier. We further investigated the reliability of neural envelope tracking and the required recording length for accurate aphasia detection. Our results showed that individuals with aphasia had decreased encoding of the envelope compared to controls in the broad, delta, theta and gamma bands, which aligns with the assumed role of these bands in auditory and linguistic processing of speech. Neural tracking in these frequency bands effectively captured aphasia at the individual level, with a classification accuracy of 83.33% and an area under the curve of 89.16%. Moreover, we demonstrated that high-accuracy detection of aphasia can be achieved in a time-efficient (5-7 min) and highly reliable manner (split-half reliability correlations between R = 0.61 and R = 0.96 across frequency bands). In this study, we identified specific neural response characteristics to natural speech that are impaired in individuals with aphasia, holding promise as a potential biomarker for the condition. Furthermore, we demonstrate that the neural tracking technique can discriminate aphasia from healthy controls at the individual level with high accuracy, and in a reliable and time-efficient manner. Our findings represent a significant advance towards more automated, objective and ecologically valid assessments of language impairments in aphasia.

Project description:The decoding multivariate Temporal Response Function (decoder) or speech envelope reconstruction approach is a well-known tool for assessing the cortical tracking of speech envelope. It is used to analyse the correlation between the speech stimulus and the neural response. It is known that auditory late responses are enhanced with longer gaps between stimuli, but it is not clear if this applies to the decoder, and whether the addition of gaps/pauses in continuous speech could be used to increase the envelope reconstruction accuracy. We investigated this in normal hearing participants who listened to continuous speech with no added pauses (natural speech), and then with short (250 ms) or long (500 ms) silent pauses inserted between each word. The total duration for continuous speech stimulus with no, short, and long pauses were approximately, 10 minutes, 16 minutes, and 21 minutes, respectively. EEG and speech envelope were simultaneously acquired and then filtered into delta (1-4 Hz) and theta (4-8 Hz) frequency bands. In addition to analysing responses to the whole speech envelope, speech envelope was also segmented to focus response analysis on onset and non-onset regions of speech separately. Our results show that continuous speech with additional pauses inserted between words significantly increases the speech envelope reconstruction correlations compared to using natural speech, in both the delta and theta frequency bands. It also appears that these increase in speech envelope reconstruction are dominated by the onset regions in the speech envelope. Introducing pauses in speech stimuli has potential clinical benefit for increasing auditory evoked response detectability, though with the disadvantage of speech sounding less natural. The strong effect of pauses and onsets on the decoder should be considered when comparing results from different speech corpora. Whether the increased cortical response, when longer pauses are introduced, reflect improved intelligibility requires further investigation.

Project description:PurposeBehaviorally, acquired apraxia of speech (AOS) is a multidimensional syndrome that the experienced clinician recognizes based on impaired articulation and abnormal temporal prosody. We conducted this study to determine the extent to which three core features of AOS-when defined quantitatively-distinguish categorically among aphasia with no or minimal speech sound involvement, aphasia with AOS, and aphasia with phonemic paraphasia (APP).MethodThe study involved retrospective analysis of 195 participants with stroke-induced aphasia. We used three quantitative measures (phonemic error frequency, distortion error frequency, and word syllable duration [WSD]) to divide the sample into four participant groups according to the most likely speech diagnosis: aphasia with minimal speech sound errors, AOS, APP, and a borderline group with mixed profiles. We then conducted nonparametric comparisons across groups for which the measures were not defined and visualized all three measures in a three-dimensional graph.ResultsThe measures distributed as multidimensional spectra rather than discrete diagnostic entities, and there was considerable behavioral overlap among participant groups. Thirty percent of participants presented with aphasia with minimal sound production difficulties, and they were statistically indistinguishable from the APP group on distortion frequency and WSD. Distortion frequency and WSD were in a borderline region between AOS and APP for 29% of participants. Compared to all other groups, participants with AOS produced significantly more errors that affected listeners' phonemic perception.ConclusionsThe results suggest that the current AOS-APP dichotomy has limited validity. We conclude that a continuous multidimensional view of speech variation would be a constructive perspective from which to understand how the left cerebral hemisphere produces speech and that quantitative and normed speech measures should be used to inform differential diagnosis in clinical settings.Supplemental materialhttps://doi.org/10.23641/asha.21807609.

Project description:BackgroundAphasia is an acquired language impairment following brain damage that affects some or all language modalities: expression and understanding of speech, reading, and writing. Approximately one third of people who have a stroke experience aphasia.ObjectivesTo assess the effects of speech and language therapy (SLT) for aphasia following stroke.Search methodsWe searched the Cochrane Stroke Group Trials Register (last searched 9 September 2015), CENTRAL (2015, Issue 5) and other Cochrane Library Databases (CDSR, DARE, HTA, to 22 September 2015), MEDLINE (1946 to September 2015), EMBASE (1980 to September 2015), CINAHL (1982 to September 2015), AMED (1985 to September 2015), LLBA (1973 to September 2015), and SpeechBITE (2008 to September 2015). We also searched major trials registers for ongoing trials including ClinicalTrials.gov (to 21 September 2015), the Stroke Trials Registry (to 21 September 2015), Current Controlled Trials (to 22 September 2015), and WHO ICTRP (to 22 September 2015). In an effort to identify further published, unpublished, and ongoing trials we also handsearched the International Journal of Language and Communication Disorders (1969 to 2005) and reference lists of relevant articles, and we contacted academic institutions and other researchers. There were no language restrictions.Selection criteriaRandomised controlled trials (RCTs) comparing SLT (a formal intervention that aims to improve language and communication abilities, activity and participation) versus no SLT; social support or stimulation (an intervention that provides social support and communication stimulation but does not include targeted therapeutic interventions); or another SLT intervention (differing in duration, intensity, frequency, intervention methodology or theoretical approach).Data collection and analysisWe independently extracted the data and assessed the quality of included trials. We sought missing data from investigators.Main resultsWe included 57 RCTs (74 randomised comparisons) involving 3002 participants in this review (some appearing in more than one comparison). Twenty-seven randomised comparisons (1620 participants) assessed SLT versus no SLT; SLT resulted in clinically and statistically significant benefits to patients' functional communication (standardised mean difference (SMD) 0.28, 95% confidence interval (CI) 0.06 to 0.49, P = 0.01), reading, writing, and expressive language, but (based on smaller numbers) benefits were not evident at follow-up. Nine randomised comparisons (447 participants) assessed SLT with social support and stimulation; meta-analyses found no evidence of a difference in functional communication, but more participants withdrew from social support interventions than SLT. Thirty-eight randomised comparisons (1242 participants) assessed two approaches to SLT. Functional communication was significantly better in people with aphasia that received therapy at a high intensity, high dose, or over a long duration compared to those that received therapy at a lower intensity, lower dose, or over a shorter period of time. The benefits of a high intensity or a high dose of SLT were confounded by a significantly higher dropout rate in these intervention groups. Generally, trials randomised small numbers of participants across a range of characteristics (age, time since stroke, and severity profiles), interventions, and outcomes.Authors' conclusionsOur review provides evidence of the effectiveness of SLT for people with aphasia following stroke in terms of improved functional communication, reading, writing, and expressive language compared with no therapy. There is some indication that therapy at high intensity, high dose or over a longer period may be beneficial. HIgh-intensity and high dose interventions may not be acceptable to all.

Dataset Information

Examining cortical tracking of the speech envelope in post-stroke aphasia.

Introduction

Methods

Results

Conclusion

Publications

Examining cortical tracking of the speech envelope in post-stroke aphasia.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets