Neural tracking measures of speech intelligibility: Manipulating intelligibility while keeping acoustics unchanged

Proceedings of the National Academy of Sciences, Год журнала: 2023, Номер 120(49)

Опубликована: Ноя. 30, 2023

Neural speech tracking has advanced our understanding of how brains rapidly map an acoustic signal onto linguistic representations and ultimately meaning. It remains unclear, however, intelligibility is related to the corresponding neural responses. Many studies addressing this question vary level by manipulating waveform, but makes it difficult cleanly disentangle effects from underlying acoustical confounds. Here, using magnetoencephalography recordings, we study measures while keeping acoustics strictly unchanged. Acoustically identical degraded stimuli (three-band noise-vocoded, ~20 s duration) are presented twice, second presentation preceded original (nondegraded) version speech. This intermediate priming, which generates a "pop-out" percept, substantially improves passage. We investigate structure affect multivariate temporal response functions (mTRFs). As expected, behavioral results confirm that perceived clarity improved priming. mTRFs analysis reveals auditory (speech envelope onset) not affected priming only (bottom-up driven). Critically, findings suggest segmentation sounds into words emerges with better intelligibility, most strongly at later (~400 ms latency) word processing stage, in prefrontal cortex, line engagement top-down mechanisms associated Taken together, show may provide some objective comprehension.

Язык: Английский

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Isolating neural signatures of conscious speech perception with a no-report sine-wave speech paradigm

Journal of Neuroscience, Год журнала: 2024, Номер unknown, С. e0145232023 - e0145232023

Опубликована: Янв. 8, 2024

Identifying neural correlates of conscious perception is a fundamental endeavor cognitive neuroscience. Most studies so far have focused on visual awareness along with trial-by-trial reports task relevant stimuli, which can confound measures perceptual post-perceptual processing. Here, we used three-phase sine-wave speech paradigm that dissociated between and relevance while recording EEG in humans both sexes. Compared to tokens perceived as noise, physically identical were elicited left-lateralized, near-vertex negativity, interpret phonological version negativity. This response appeared 200 300 ms after token onset was not present for frequency-flipped control never speech. In contrast, the P3b by task-irrelevant did significantly differ when versus only enhanced task. Our results extend findings from previous perception, suggest across types content, are most likely be found mid-latency negative-going brain responses content-specific sensory areas. Significance Statement How patterns activity give rise question asked whether markers separated task-related confounds. We combined - degraded signal heard noise naive individuals but readily minimal training no-report independently manipulated (speech non-speech) (relevant irrelevant). Using this paradigm, able identify marker over left frontotemporal channels independent demonstrate “perceptual negativity” new type content (speech).

Язык: Английский

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A listening advantage for native speech is reflected by attention-related activity in auditory cortex

Communications Biology, Год журнала: 2025, Номер 8(1)

Опубликована: Фев. 5, 2025

Язык: Английский

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Speech Reception Threshold Estimation via EEG‐Based Continuous Speech Envelope Reconstruction

European Journal of Neuroscience, Год журнала: 2025, Номер 61(6)

Опубликована: Март 1, 2025

ABSTRACT This study investigates the potential of speech reception threshold (SRT) estimation through electroencephalography (EEG) based envelope reconstruction techniques with continuous speech. Additionally, we investigate influence stimuli's signal‐to‐noise ratio (SNR) on temporal response function (TRF). Twenty young normal‐hearing participants listened to audiobook excerpts varying background noise levels while EEG was recorded. A linear decoder trained reconstruct from data. The accuracy calculated as Pearson's correlation between reconstructed and actual envelopes. An SRT estimate (SRT neuro ) obtained midpoint a sigmoid fitted versus SNR data points. TRF estimated at each level, followed by statistical analysis reveal significant effects latencies amplitudes most prominent components. within 3 dB behavioral for all participants. showed latency decrease N1 P2 amplitude magnitude increase increasing SNR. results suggest that both components are influenced changes in SNR, indicating they may be linked same underlying neural process.

Язык: Английский

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Neural substrates and behavioral relevance of speech envelope tracking: evidence from post-stroke aphasia

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Март 28, 2024

Abstract Neural tracking of the low-frequency temporal envelope speech has emerged as a prominent tool to investigate neural mechanisms natural processing in brain. However, there is ongoing debate regarding functional role tracking. In this context, our study aims offer novel perspective by investigating critical brain areas and behavioral skills required for aphasia, language disorder characterized impaired We analyzed an EEG dataset 39 individuals with post-stroke aphasia suffering left-hemispheric stroke who listened speech. Our analysis involved lesion mapping, where left lesioned voxels served binary features predict measures. also examined correlates receptive language, naming, auditory (via rise time discrimination task) skills. The mapping revealed that lesions areas, such middle gyrus, supramarginal gyrus angular were associated poorer Additionally, was related (receptive naming) effects on less robust, possibly due ceiling scores. findings highlight importance central implicated understanding, extending beyond primary cortex, emphasize intact abilities effectively Collectively, these underscore significance mere audibility acoustic processes. Significance statement While some studies have proposed primarily relates processes, others suggested its involvement actual comprehension. By essential we argue broader processing. Furthermore, specificity among indicating correlation regions functions. This addresses significant heterogeneity characteristics present suggests potential EEG-based specifically assessing population.

Язык: Английский

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Neural Decoding of the Speech Envelope: Effects of Intelligibility and Spectral Degradation

Trends in Hearing, Год журнала: 2024, Номер 28

Опубликована: Янв. 1, 2024

During continuous speech perception, endogenous neural activity becomes time-locked to acoustic stimulus features, such as the amplitude envelope. This speech–brain coupling can be decoded using non-invasive brain imaging techniques, including electroencephalography (EEG). Neural decoding may provide clinical use an objective measure of encoding by brain—for example during cochlear implant listening, wherein signal is severely spectrally degraded. Yet, interplay between and linguistic factors lead top-down modulation thereby complicating audiological applications. To address this ambiguity, we assess envelope under spectral degradation with EEG in acoustically hearing listeners ( n = 38; 18–35 years old) vocoded speech. We dissociate sensory from higher-order processing employing intelligible (English) non-intelligible (Dutch) stimuli, auditory attention sustained a repeated-phrase detection task. Subject-specific group decoders were trained reconstruct held-out data, decoder significance determined via random permutation testing. Whereas reconstruction did not vary resolution, was associated better accuracy general. Results similar across subject-specific analyses, less consistent effects decoding. Permutation tests revealed possible differences statistical experimental condition. In general, while robust observed at individual level, variability within participants would most likely prevent differentiate levels intelligibility on basis.

Язык: Английский

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Neural tracking of the speech envelope predicts binaural unmasking

European Journal of Neuroscience, Год журнала: 2024, Номер unknown

Опубликована: Дек. 9, 2024

Abstract Binaural unmasking is a remarkable phenomenon that it substantially easier to detect signal in noise when the interaural parameters of are different from those – useful mechanism so‐called cocktail party scenarios. In this study, we investigated effect binaural on neural tracking speech envelope. We measured EEG 8 participants who listened at fixed signal‐to‐noise ratio, two conditions: one where and had same phase difference (both having an opposite waveform across ears, SπNπ ), was (only SπN ). clear benefit behavioural understanding scores, accompanied by increased Moreover, analysing temporal response functions revealed also resulted decreased peak latencies amplitudes. Our results consistent with previous research using auditory evoked potentials steady‐state responses quantify cortical levels. they confirm associated understanding, even if acoustic ratio kept constant. From clinical perspective, these offer potential for objective evaluation mechanisms, detection pathologies sensitive processing, such as asymmetric hearing loss, neuropathy age‐related deficits.

Язык: Английский

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The human auditory cortex concurrently tracks syllabic and phonemic timescales via acoustic spectral flux

Science Advances, Год журнала: 2024, Номер 10(51)

Опубликована: Дек. 20, 2024

Dynamical theories of speech processing propose that the auditory cortex parses acoustic information in parallel at syllabic and phonemic timescales. We developed a paradigm to independently manipulate both linguistic timescales, acquired intracranial recordings from 11 patients who are epileptic listening French sentences. Our results indicate (i) timescales reflected spectral flux; (ii) during comprehension, tracks timescale theta range, while neural activity alpha-beta range phase locks timescale; (iii) these dynamics occur simultaneously share joint spatial location; (iv) flux embeds two timescales-in low-beta ranges-across 17 natural languages. These findings help us understand how human brain extracts continuous signal multiple simultaneously, prerequisite for subsequent processing.

Язык: Английский

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Neural Dynamics of the Processing of Speech Features: Evidence for a Progression of Features from Acoustic to Sentential Processing

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Фев. 2, 2024

When we listen to speech, our brain's neurophysiological responses "track" its acoustic features, but it is less well understood how these auditory are modulated by linguistic content. Here, recorded magnetoencephalography (MEG) while subjects listened four types of continuous-speech-like passages: speech-envelope noise, English-like non-words, scrambled words, and narrative passage. Temporal response function (TRF) analysis provides strong neural evidence for the emergent features speech processing in cortex, from acoustics higher-level linguistics, as incremental steps processing. Critically, show a stepwise hierarchical progression progressively higher order over time, reflected both bottom-up (early) top-down (late) stages. Linguistically driven mechanisms take form late N400-like responses, suggesting central role predictive coding at multiple levels. As expected, lower-level feature bilateral or right lateralized, with left lateralization emerging only lexical-semantic features. Finally, results identify potential markers computations underlying perception comprehension.

Язык: Английский

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Neural decoding of the speech envelope: Effects of intelligibility and spectral degradation

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Фев. 23, 2024

During continuous speech perception, endogenous neural activity becomes time-locked to acoustic stimulus features, such as the amplitude envelope. This speech-brain coupling can be decoded using non-invasive brain imaging techniques, including electroencephalography (EEG). Neural decoding may provide clinical use an objective measure of encoding by - for example during cochlear implant (CI) listening, wherein signal is severely spectrally degraded. Yet, interplay between and linguistic factors lead top-down modulation thereby complicating audiological applications. To address this ambiguity, we assess envelope under spectral degradation with EEG in acoustically hearing listeners (n = 38; 18-35 years old) vocoded speech. We dissociate sensory from higher-order processing employing intelligible (English) non-intelligible (Dutch) stimuli, auditory attention sustained a repeated-phrase detection task. Subject-specific group decoders were trained reconstruct held-out data, decoder significance determined via random permutation testing. Whereas reconstruction did not vary resolution, was associated better accuracy general. Results similar across subject-specific analyses, less consistent effects decoding. Permutation tests revealed possible differences statistical experimental condition. In general, while robust observed at individual level, variability within participants would most likely prevent differentiate levels intelligibility on basis.

Язык: Английский

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