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Chalas N, Meyer L, Lo CW, Park H, Kluger DS, Abbasi O, Kayser C, Nitsch R, Gross J. Dissociating prosodic from syntactic delta activity during natural speech comprehension. Curr Biol 2024; 34:3537-3549.e5. [PMID: 39047734 DOI: 10.1016/j.cub.2024.06.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/27/2024]
Abstract
Decoding human speech requires the brain to segment the incoming acoustic signal into meaningful linguistic units, ranging from syllables and words to phrases. Integrating these linguistic constituents into a coherent percept sets the root of compositional meaning and hence understanding. One important cue for segmentation in natural speech is prosodic cues, such as pauses, but their interplay with higher-level linguistic processing is still unknown. Here, we dissociate the neural tracking of prosodic pauses from the segmentation of multi-word chunks using magnetoencephalography (MEG). We find that manipulating the regularity of pauses disrupts slow speech-brain tracking bilaterally in auditory areas (below 2 Hz) and in turn increases left-lateralized coherence of higher-frequency auditory activity at speech onsets (around 25-45 Hz). Critically, we also find that multi-word chunks-defined as short, coherent bundles of inter-word dependencies-are processed through the rhythmic fluctuations of low-frequency activity (below 2 Hz) bilaterally and independently of prosodic cues. Importantly, low-frequency alignment at chunk onsets increases the accuracy of an encoding model in bilateral auditory and frontal areas while controlling for the effect of acoustics. Our findings provide novel insights into the neural basis of speech perception, demonstrating that both acoustic features (prosodic cues) and abstract linguistic processing at the multi-word timescale are underpinned independently by low-frequency electrophysiological brain activity in the delta frequency range.
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Affiliation(s)
- Nikos Chalas
- Institute for Biomagnetism and Biosignal Analysis, University of Münster, Münster, Germany; Otto-Creutzfeldt-Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany; Institute for Translational Neuroscience, University of Münster, Münster, Germany.
| | - Lars Meyer
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Chia-Wen Lo
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Hyojin Park
- Centre for Human Brain Health (CHBH), School of Psychology, University of Birmingham, Birmingham, UK
| | - Daniel S Kluger
- Institute for Biomagnetism and Biosignal Analysis, University of Münster, Münster, Germany; Otto-Creutzfeldt-Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Omid Abbasi
- Institute for Biomagnetism and Biosignal Analysis, University of Münster, Münster, Germany
| | - Christoph Kayser
- Department for Cognitive Neuroscience, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
| | - Robert Nitsch
- Institute for Translational Neuroscience, University of Münster, Münster, Germany
| | - Joachim Gross
- Institute for Biomagnetism and Biosignal Analysis, University of Münster, Münster, Germany; Otto-Creutzfeldt-Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
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2
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Do J, James O, Kim YJ. Choice-dependent delta-band neural trajectory during semantic category decision making in the human brain. iScience 2024; 27:110173. [PMID: 39040068 PMCID: PMC11260863 DOI: 10.1016/j.isci.2024.110173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 04/15/2024] [Accepted: 05/31/2024] [Indexed: 07/24/2024] Open
Abstract
Recent human brain imaging studies have identified widely distributed cortical areas that represent information about the meaning of language. Yet, the dynamic nature of widespread neural activity as a correlate of the semantic information processing remains poorly explored. Our state space analysis of electroencephalograms (EEGs) recorded during semantic match-to-category task show that depending on the semantic category and decision path chosen by participants, whole-brain delta-band dynamics follow distinct trajectories that are correlated with participants' response time on a trial-by-trial basis. Especially, the proximity of the neural trajectory to category decision-specific region in the state space was predictive of participants' decision-making reaction times. We also found that posterolateral regions primarily encoded word categories while postero-central regions encoded category decisions. Our results demonstrate the role of neural dynamics embedded in the evolving multivariate delta-band activity patterns in processing the semantic relatedness of words and the semantic category-based decision-making.
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Affiliation(s)
- Jongrok Do
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Republic of Korea
| | - Oliver James
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Republic of Korea
| | - Yee-Joon Kim
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Republic of Korea
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3
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He D, Buder EH, Bidelman GM. Cross-linguistic and acoustic-driven effects on multiscale neural synchrony to stress rhythms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.04.570012. [PMID: 38106017 PMCID: PMC10723321 DOI: 10.1101/2023.12.04.570012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
We investigated how neural oscillations code the hierarchical nature of stress rhythms in speech and how stress processing varies with language experience. By measuring phase synchrony of multilevel EEG-acoustic tracking and intra-brain cross-frequency coupling, we show the encoding of stress involves different neural signatures (delta rhythms = stress foot rate; theta rhythms = syllable rate), is stronger for amplitude vs. duration stress cues, and induces nested delta-theta coherence mirroring the stress-syllable hierarchy in speech. Only native English, but not Mandarin, speakers exhibited enhanced neural entrainment at central stress (2 Hz) and syllable (4 Hz) rates intrinsic to natural English. English individuals with superior cortical-stress tracking capabilities also displayed stronger neural hierarchical coherence, highlighting a nuanced interplay between internal nesting of brain rhythms and external entrainment rooted in language-specific speech rhythms. Our cross-language findings reveal brain-speech synchronization is not purely a "bottom-up" but benefits from "top-down" processing from listeners' language-specific experience.
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Affiliation(s)
- Deling He
- School of Communication Sciences & Disorders, University of Memphis, Memphis, TN, USA
- Institute for Intelligent Systems, University of Memphis, Memphis, TN, USA
| | - Eugene H. Buder
- School of Communication Sciences & Disorders, University of Memphis, Memphis, TN, USA
- Institute for Intelligent Systems, University of Memphis, Memphis, TN, USA
| | - Gavin M. Bidelman
- Department of Speech, Language and Hearing Sciences, Indiana University, Bloomington, IN, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, USA
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Li J, Hong B, Nolte G, Engel AK, Zhang D. EEG-based speaker-listener neural coupling reflects speech-selective attentional mechanisms beyond the speech stimulus. Cereb Cortex 2023; 33:11080-11091. [PMID: 37814353 DOI: 10.1093/cercor/bhad347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 10/11/2023] Open
Abstract
When we pay attention to someone, do we focus only on the sound they make, the word they use, or do we form a mental space shared with the speaker we want to pay attention to? Some would argue that the human language is no other than a simple signal, but others claim that human beings understand each other because they form a shared mental ground between the speaker and the listener. Our study aimed to explore the neural mechanisms of speech-selective attention by investigating the electroencephalogram-based neural coupling between the speaker and the listener in a cocktail party paradigm. The temporal response function method was employed to reveal how the listener was coupled to the speaker at the neural level. The results showed that the neural coupling between the listener and the attended speaker peaked 5 s before speech onset at the delta band over the left frontal region, and was correlated with speech comprehension performance. In contrast, the attentional processing of speech acoustics and semantics occurred primarily at a later stage after speech onset and was not significantly correlated with comprehension performance. These findings suggest a predictive mechanism to achieve speaker-listener neural coupling for successful speech comprehension.
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Affiliation(s)
- Jiawei Li
- Department of Psychology, School of Social Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
- Department of Education and Psychology, Freie Universität Berlin, Habelschwerdter Allee, Berlin 14195, Germany
| | - Bo Hong
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Guido Nolte
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Andreas K Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Dan Zhang
- Department of Psychology, School of Social Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua Laboratory of Brain and Intelligence, Tsinghua University, Beijing 100084, China
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Mohammadi Y, Graversen C, Østergaard J, Andersen OK, Reichenbach T. Phase-locking of Neural Activity to the Envelope of Speech in the Delta Frequency Band Reflects Differences between Word Lists and Sentences. J Cogn Neurosci 2023; 35:1301-1311. [PMID: 37379482 DOI: 10.1162/jocn_a_02016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
The envelope of a speech signal is tracked by neural activity in the cerebral cortex. The cortical tracking occurs mainly in two frequency bands, theta (4-8 Hz) and delta (1-4 Hz). Tracking in the faster theta band has been mostly associated with lower-level acoustic processing, such as the parsing of syllables, whereas the slower tracking in the delta band relates to higher-level linguistic information of words and word sequences. However, much regarding the more specific association between cortical tracking and acoustic as well as linguistic processing remains to be uncovered. Here, we recorded EEG responses to both meaningful sentences and random word lists in different levels of signal-to-noise ratios (SNRs) that lead to different levels of speech comprehension as well as listening effort. We then related the neural signals to the acoustic stimuli by computing the phase-locking value (PLV) between the EEG recordings and the speech envelope. We found that the PLV in the delta band increases with increasing SNR for sentences but not for the random word lists, showing that the PLV in this frequency band reflects linguistic information. When attempting to disentangle the effects of SNR, speech comprehension, and listening effort, we observed a trend that the PLV in the delta band might reflect listening effort rather than the other two variables, although the effect was not statistically significant. In summary, our study shows that the PLV in the delta band reflects linguistic information and might be related to listening effort.
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Koirala N, Deroche MLD, Wolfe J, Neumann S, Bien AG, Doan D, Goldbeck M, Muthuraman M, Gracco VL. Dynamic networks differentiate the language ability of children with cochlear implants. Front Neurosci 2023; 17:1141886. [PMID: 37409105 PMCID: PMC10318154 DOI: 10.3389/fnins.2023.1141886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/29/2023] [Indexed: 07/07/2023] Open
Abstract
Background Cochlear implantation (CI) in prelingually deafened children has been shown to be an effective intervention for developing language and reading skill. However, there is a substantial proportion of the children receiving CI who struggle with language and reading. The current study-one of the first to implement electrical source imaging in CI population was designed to identify the neural underpinnings in two groups of CI children with good and poor language and reading skill. Methods Data using high density electroencephalography (EEG) under a resting state condition was obtained from 75 children, 50 with CIs having good (HL) or poor language skills (LL) and 25 normal hearing (NH) children. We identified coherent sources using dynamic imaging of coherent sources (DICS) and their effective connectivity computing time-frequency causality estimation based on temporal partial directed coherence (TPDC) in the two CI groups compared to a cohort of age and gender matched NH children. Findings Sources with higher coherence amplitude were observed in three frequency bands (alpha, beta and gamma) for the CI groups when compared to normal hearing children. The two groups of CI children with good (HL) and poor (LL) language ability exhibited not only different cortical and subcortical source profiles but also distinct effective connectivity between them. Additionally, a support vector machine (SVM) algorithm using these sources and their connectivity patterns for each CI group across the three frequency bands was able to predict the language and reading scores with high accuracy. Interpretation Increased coherence in the CI groups suggest overall that the oscillatory activity in some brain areas become more strongly coupled compared to the NH group. Moreover, the different sources and their connectivity patterns and their association to language and reading skill in both groups, suggest a compensatory adaptation that either facilitated or impeded language and reading development. The neural differences in the two groups of CI children may reflect potential biomarkers for predicting outcome success in CI children.
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Affiliation(s)
- Nabin Koirala
- Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, United States
| | | | - Jace Wolfe
- Hearts for Hearing Foundation, Oklahoma City, OK, United States
| | - Sara Neumann
- Hearts for Hearing Foundation, Oklahoma City, OK, United States
| | - Alexander G. Bien
- Department of Otolaryngology – Head and Neck Surgery, University of Oklahoma Medical Center, Oklahoma City, OK, United States
| | - Derek Doan
- University of Oklahoma College of Medicine, Oklahoma City, OK, United States
| | - Michael Goldbeck
- University of Oklahoma College of Medicine, Oklahoma City, OK, United States
| | - Muthuraman Muthuraman
- Department of Neurology, Neural Engineering with Signal Analytics and Artificial Intelligence (NESA-AI), Universitätsklinikum Würzburg, Würzburg, Germany
| | - Vincent L. Gracco
- Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, United States
- School of Communication Sciences and Disorders, McGill University, Montreal, QC, Canada
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7
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Woolnough O, Donos C, Murphy E, Rollo PS, Roccaforte ZJ, Dehaene S, Tandon N. Spatiotemporally distributed frontotemporal networks for sentence reading. Proc Natl Acad Sci U S A 2023; 120:e2300252120. [PMID: 37068244 PMCID: PMC10151604 DOI: 10.1073/pnas.2300252120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/14/2023] [Indexed: 04/19/2023] Open
Abstract
Reading a sentence entails integrating the meanings of individual words to infer more complex, higher-order meaning. This highly rapid and complex human behavior is known to engage the inferior frontal gyrus (IFG) and middle temporal gyrus (MTG) in the language-dominant hemisphere, yet whether there are distinct contributions of these regions to sentence reading is still unclear. To probe these neural spatiotemporal dynamics, we used direct intracranial recordings to measure neural activity while reading sentences, meaning-deficient Jabberwocky sentences, and lists of words or pseudowords. We isolated two functionally and spatiotemporally distinct frontotemporal networks, each sensitive to distinct aspects of word and sentence composition. The first distributed network engages the IFG and MTG, with IFG activity preceding MTG. Activity in this network ramps up over the duration of a sentence and is reduced or absent during Jabberwocky and word lists, implying its role in the derivation of sentence-level meaning. The second network engages the superior temporal gyrus and the IFG, with temporal responses leading those in frontal lobe, and shows greater activation for each word in a list than those in sentences, suggesting that sentential context enables greater efficiency in the lexical and/or phonological processing of individual words. These adjacent, yet spatiotemporally dissociable neural mechanisms for word- and sentence-level processes shed light on the richly layered semantic networks that enable us to fluently read. These results imply distributed, dynamic computation across the frontotemporal language network rather than a clear dichotomy between the contributions of frontal and temporal structures.
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Affiliation(s)
- Oscar Woolnough
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX77030
- Texas Institute for Restorative Neurotechnologies, University of Texas Health Science Center at Houston, Houston, TX77030
| | - Cristian Donos
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX77030
- Faculty of Physics, University of Bucharest, 050663Bucharest, Romania
| | - Elliot Murphy
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX77030
- Texas Institute for Restorative Neurotechnologies, University of Texas Health Science Center at Houston, Houston, TX77030
| | - Patrick S. Rollo
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX77030
- Texas Institute for Restorative Neurotechnologies, University of Texas Health Science Center at Houston, Houston, TX77030
| | - Zachary J. Roccaforte
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX77030
- Texas Institute for Restorative Neurotechnologies, University of Texas Health Science Center at Houston, Houston, TX77030
| | - Stanislas Dehaene
- Cognitive Neuroimaging Unit, Université Paris-Saclay, INSERM, CEA, NeuroSpin Center, 91191Gif-sur-Yvette, France
- Collège de France, 75005Paris, France
| | - Nitin Tandon
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX77030
- Texas Institute for Restorative Neurotechnologies, University of Texas Health Science Center at Houston, Houston, TX77030
- Memorial Hermann Hospital, Texas Medical Center, Houston, TX77030
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8
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Luo C, Gao Y, Fan J, Liu Y, Yu Y, Zhang X. Compromised word-level neural tracking in the high-gamma band for children with attention deficit hyperactivity disorder. Front Hum Neurosci 2023; 17:1174720. [PMID: 37213926 PMCID: PMC10196181 DOI: 10.3389/fnhum.2023.1174720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/18/2023] [Indexed: 05/23/2023] Open
Abstract
Children with attention deficit hyperactivity disorder (ADHD) exhibit pervasive difficulties in speech perception. Given that speech processing involves both acoustic and linguistic stages, it remains unclear which stage of speech processing is impaired in children with ADHD. To investigate this issue, we measured neural tracking of speech at syllable and word levels using electroencephalography (EEG), and evaluated the relationship between neural responses and ADHD symptoms in 6-8 years old children. Twenty-three children participated in the current study, and their ADHD symptoms were assessed with SNAP-IV questionnaires. In the experiment, the children listened to hierarchical speech sequences in which syllables and words were, respectively, repeated at 2.5 and 1.25 Hz. Using frequency domain analyses, reliable neural tracking of syllables and words was observed in both the low-frequency band (<4 Hz) and the high-gamma band (70-160 Hz). However, the neural tracking of words in the high-gamma band showed an anti-correlation with the ADHD symptom scores of the children. These results indicate that ADHD prominently impairs cortical encoding of linguistic information (e.g., words) in speech perception.
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Affiliation(s)
- Cheng Luo
- Research Center for Applied Mathematics and Machine Intelligence, Research Institute of Basic Theories, Zhejiang Lab, Hangzhou, China
- Cheng Luo,
| | - Yayue Gao
- Department of Psychology, School of Humanities and Social Sciences, Beihang University, Beijing, China
- *Correspondence: Yayue Gao,
| | - Jianing Fan
- Department of Psychology, School of Humanities and Social Sciences, Beihang University, Beijing, China
| | - Yang Liu
- Department of Psychology, School of Humanities and Social Sciences, Beihang University, Beijing, China
| | - Yonglin Yu
- Department of Rehabilitation, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
- Yonglin Yu,
| | - Xin Zhang
- Department of Neurology, The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
- Xin Zhang,
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Liu Y, Luo C, Zheng J, Liang J, Ding N. Working memory asymmetrically modulates auditory and linguistic processing of speech. Neuroimage 2022; 264:119698. [PMID: 36270622 DOI: 10.1016/j.neuroimage.2022.119698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [Indexed: 11/09/2022] Open
Abstract
Working memory load can modulate speech perception. However, since speech perception and working memory are both complex functions, it remains elusive how each component of the working memory system interacts with each speech processing stage. To investigate this issue, we concurrently measure how the working memory load modulates neural activity tracking three levels of linguistic units, i.e., syllables, phrases, and sentences, using a multiscale frequency-tagging approach. Participants engage in a sentence comprehension task and the working memory load is manipulated by asking them to memorize either auditory verbal sequences or visual patterns. It is found that verbal and visual working memory load modulate speech processing in similar manners: Higher working memory load attenuates neural activity tracking of phrases and sentences but enhances neural activity tracking of syllables. Since verbal and visual WM load similarly influence the neural responses to speech, such influences may derive from the domain-general component of WM system. More importantly, working memory load asymmetrically modulates lower-level auditory encoding and higher-level linguistic processing of speech, possibly reflecting reallocation of attention induced by mnemonic load.
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Affiliation(s)
- Yiguang Liu
- Research Center for Applied Mathematics and Machine Intelligence, Research Institute of Basic Theories, Zhejiang Lab, Hangzhou 311121, China
| | - Cheng Luo
- Research Center for Applied Mathematics and Machine Intelligence, Research Institute of Basic Theories, Zhejiang Lab, Hangzhou 311121, China
| | - Jing Zheng
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou 310027, China
| | - Junying Liang
- Department of Linguistics, School of International Studies, Zhejiang University, Hangzhou 310058, China
| | - Nai Ding
- Research Center for Applied Mathematics and Machine Intelligence, Research Institute of Basic Theories, Zhejiang Lab, Hangzhou 311121, China; Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou 310027, China; The MOE Frontier Science Center for Brain Science & Brain-machine Integration, Zhejiang University, Hangzhou 310012, China.
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10
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Lo CW, Tung TY, Ke AH, Brennan JR. Hierarchy, Not Lexical Regularity, Modulates Low-Frequency Neural Synchrony During Language Comprehension. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2022; 3:538-555. [PMID: 37215342 PMCID: PMC10158645 DOI: 10.1162/nol_a_00077] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 06/20/2022] [Indexed: 05/24/2023]
Abstract
Neural responses appear to synchronize with sentence structure. However, researchers have debated whether this response in the delta band (0.5-3 Hz) really reflects hierarchical information or simply lexical regularities. Computational simulations in which sentences are represented simply as sequences of high-dimensional numeric vectors that encode lexical information seem to give rise to power spectra similar to those observed for sentence synchronization, suggesting that sentence-level cortical tracking findings may reflect sequential lexical or part-of-speech information, and not necessarily hierarchical syntactic information. Using electroencephalography (EEG) data and the frequency-tagging paradigm, we develop a novel experimental condition to tease apart the predictions of the lexical and the hierarchical accounts of the attested low-frequency synchronization. Under a lexical model, synchronization should be observed even when words are reversed within their phrases (e.g., "sheep white grass eat" instead of "white sheep eat grass"), because the same lexical items are preserved at the same regular intervals. Critically, such stimuli are not syntactically well-formed; thus a hierarchical model does not predict synchronization of phrase- and sentence-level structure in the reversed phrase condition. Computational simulations confirm these diverging predictions. EEG data from N = 31 native speakers of Mandarin show robust delta synchronization to syntactically well-formed isochronous speech. Importantly, no such pattern is observed for reversed phrases, consistent with the hierarchical, but not the lexical, accounts.
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Affiliation(s)
- Chia-Wen Lo
- Research Group Language Cycles, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Department of Linguistics, University of Michigan, Ann Arbor, MI, USA
| | - Tzu-Yun Tung
- Department of Linguistics, University of Michigan, Ann Arbor, MI, USA
| | - Alan Hezao Ke
- Department of Linguistics, University of Michigan, Ann Arbor, MI, USA
- Department of Linguistics, Languages and Cultures, Michigan State University, East Lansing, MI, USA
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11
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Lu Y, Jin P, Ding N, Tian X. Delta-band neural tracking primarily reflects rule-based chunking instead of semantic relatedness between words. Cereb Cortex 2022; 33:4448-4458. [PMID: 36124831 PMCID: PMC10110438 DOI: 10.1093/cercor/bhac354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/12/2022] [Accepted: 08/13/2022] [Indexed: 11/14/2022] Open
Abstract
It is debated whether cortical responses matching the time scales of phrases and sentences mediate the mental construction of the syntactic chunks or are simply caused by the semantic properties of words. Here, we investigate to what extent delta-band neural responses to speech can be explained by semantic relatedness between words. To dissociate the contribution of semantic relatedness from sentential structures, participants listened to sentence sequences and paired-word sequences in which semantically related words repeated at 1 Hz. Semantic relatedness in the 2 types of sequences was quantified using a word2vec model that captured the semantic relation between words without considering sentential structure. The word2vec model predicted comparable 1-Hz responses with paired-word sequences and sentence sequences. However, empirical neural activity, recorded using magnetoencephalography, showed a weaker 1-Hz response to paired-word sequences than sentence sequences in a word-level task that did not require sentential processing. Furthermore, when listeners applied a task-related rule to parse paired-word sequences into multi-word chunks, 1-Hz response was stronger than that in word-level task on the same sequences. Our results suggest that cortical activity tracks multi-word chunks constructed by either syntactic rules or task-related rules, whereas the semantic relatedness between words contributes only in a minor way.
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Affiliation(s)
- Yuhan Lu
- Shanghai Key Laboratory of Brain Functional Genomics (Ministry of Education), School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China.,NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai, Shanghai 200062, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou 310027, China
| | - Peiqing Jin
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou 310027, China
| | - Nai Ding
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Sciences, Zhejiang University, Hangzhou 310027, China.,Research Center for Applied Mathematics and Machine Intelligence, Research Institute of Basic Theories, Zhejiang Lab, Hangzhou 311121, China
| | - Xing Tian
- Shanghai Key Laboratory of Brain Functional Genomics (Ministry of Education), School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China.,NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai, Shanghai 200062, China.,Division of Arts and Sciences, New York University Shanghai
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12
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Glushko A, Poeppel D, Steinhauer K. Overt and implicit prosody contribute to neurophysiological responses previously attributed to grammatical processing. Sci Rep 2022; 12:14759. [PMID: 36042220 PMCID: PMC9427746 DOI: 10.1038/s41598-022-18162-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 08/05/2022] [Indexed: 11/09/2022] Open
Abstract
Recent neurophysiological research suggests that slow cortical activity tracks hierarchical syntactic structure during online sentence processing. Here we tested an alternative hypothesis: electrophysiological activity peaks at constituent phrase as well as sentence frequencies reflect cortical tracking of overt or covert (implicit) prosodic grouping. Participants listened to series of sentences presented in three conditions while electroencephalography (EEG) was recorded. First, prosodic cues in the sentence materials were neutralized. We found an EEG spectral power peak elicited at a frequency that only ‘tagged’ covert, implicit prosodic change, but not any major syntactic constituents. In the second condition, participants listened to a series of sentences with overt prosodic grouping cues that either aligned or misaligned with the syntactic phrasing in the sentences (initial overt prosody trials). Following each overt prosody trial, participants were presented with a second series of sentences lacking overt prosodic cues (instructed prosody trial) and were instructed to imagine the prosodic contour present in the previous, overt prosody trial. The EEG responses reflected an interactive relationship between syntactic processing and prosodic tracking at the frequencies of syntactic constituents (sentences and phrases): alignment of syntax and prosody boosted EEG responses, whereas their misalignment had an opposite effect. This was true for both overt and imagined prosody conditions. We conclude that processing of both overt and covert prosody is reflected in the frequency-tagged neural responses at sentence constituent frequencies. These findings need to be incorporated in any account that aims to identify neural markers reflecting syntactic processing.
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Affiliation(s)
| | - David Poeppel
- Department of Psychology, New York University, New York City, NY, USA.,Ernst Struengmann Institute for Neuroscience, Frankfurt, Germany.,Center for Language, Music, and Emotion (CLaME), New York, USA
| | - Karsten Steinhauer
- Centre for Research on Brain, Language and Music, Montreal, Canada.,School of Communication Sciences and Disorders, McGill University, 2001 McGill College Avenue, Unit 800, Montreal, QC, H3A 1G1, Canada
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