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Hernández-Vásquez R, Córdova García U, Barreto AMB, Rojas MLR, Ponce-Meza J, Saavedra-López M. An Overview on Electrophysiological and Neuroimaging Findings in Dyslexia. IRANIAN JOURNAL OF PSYCHIATRY 2023; 18:503-509. [PMID: 37881421 PMCID: PMC10593994 DOI: 10.18502/ijps.v18i4.13638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 05/31/2023] [Accepted: 06/08/2023] [Indexed: 10/27/2023]
Abstract
Objective: Dyslexia is a prevalent neurodevelopmental condition that is characterized by inaccurate and slow word recognition. This article reviews neural correlates of dyslexia from both electrophysiological and neuroimaging studies. Method : In this brief review, we provide electrophysiological and neuroimaging evidence from electroencephalogram (EEG) and magnetic resonance imaging (MRI) studies in dyslexia to understand functional and structural brain changes in this condition. Results: In both electrophysiological and neuroimaging studies, the most frequently reported functional impairments in dyslexia include aberrant activation of the left hemisphere occipito-temporal cortex (OTC), temporo-parietal cortex (TPC), inferior frontal gyrus (IFG), and cerebellar areas. EEG studies have mostly highlighted the important role of lower frequency bands in dyslexia, especially theta waves. Furthermore, neuroimaging studies have suggested that dyslexia is related to functional and structural impairments in the left hemisphere regions associated with reading and language, including reduced grey matter volume in the left TPC, decreased white matter connectivity between reading networks, and hypo-activation of the left OTC and TPC. In addition, neural evidence from pre-reading children and infants at risk for dyslexia show that there are abnormalities in the dyslexic brain before learning to read begins. Conclusion: Advances in comprehending the neural correlates of dyslexia could bring closer translation from basic to clinical neuroscience and effective rehabilitation for individuals who struggle to read. However, neuroscience still has great potential for clinical translation that requires further research.
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Mandke K, Flanagan S, Macfarlane A, Feltham G, Gabrielczyk F, Wilson AM, Gross J, Goswami U. Neural responses to natural and enhanced speech edges in children with and without dyslexia. Front Hum Neurosci 2023; 17:1200950. [PMID: 37841072 PMCID: PMC10571917 DOI: 10.3389/fnhum.2023.1200950] [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: 04/05/2023] [Accepted: 08/31/2023] [Indexed: 10/17/2023] Open
Abstract
Sensory-neural studies indicate that children with developmental dyslexia show impairments in processing acoustic speech envelope information. Prior studies suggest that this arises in part from reduced sensory sensitivity to amplitude rise times (ARTs or speech "edges") in the envelope, accompanied by less accurate neural encoding of low-frequency envelope information. Accordingly, enhancing these characteristics of the speech envelope may enhance neural speech processing in children with dyslexia. Here we applied an envelope modulation enhancement (EME) algorithm to a 10-min story read in child-directed speech (CDS), enhancing ARTs and also enhancing low-frequency envelope information. We compared neural speech processing (as measured using MEG) for the EME story with the same story read in natural CDS for 9-year-old children with and without dyslexia. The EME story affected neural processing in the power domain for children with dyslexia, particularly in the delta band (0.5-4 Hz) in the superior temporal gyrus. This may suggest that prolonged experience with EME speech could ameliorate some of the impairments shown in natural speech processing by children with dyslexia.
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Affiliation(s)
- Kanad Mandke
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
| | - Sheila Flanagan
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
| | - Annabel Macfarlane
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
| | - Georgia Feltham
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
| | - Fiona Gabrielczyk
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
| | - Angela M. Wilson
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
| | - Joachim Gross
- Institute for Biomagnetism and Biosignal Analysis, University of Münster, Münster, Germany
| | - Usha Goswami
- Department of Psychology, Centre for Neuroscience in Education, University of Cambridge, Cambridge, United Kingdom
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The importance of temporal-fine structure to perceive time-compressed speech with and without the restoration of the syllabic rhythm. Sci Rep 2023; 13:2874. [PMID: 36806145 PMCID: PMC9938863 DOI: 10.1038/s41598-023-29755-x] [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: 02/21/2022] [Accepted: 02/09/2023] [Indexed: 02/20/2023] Open
Abstract
Intelligibility of time-compressed (TC) speech decreases with increasing speech rate. However, intelligibility can be restored by 'repackaging' the TC speech by inserting silences between the syllables so that the original 'rhythm' is restored. Although restoration of the speech rhythm affects solely the temporal envelope, it is unclear to which extent repackaging also affects the perception of the temporal-fine structure (TFS). Here we investigate to which extent TFS contributes to the perception of TC and repackaged TC speech in quiet. Intelligibility of TC sentences with a speech rate of 15.6 syllables per second (sps) and the repackaged sentences, by adding 100 ms of silence between the syllables of the TC speech (i.e., a speech rate of 6.1 sps), was assessed for three TFS conditions: the original TFS and the TFS conveyed by an 8- and 16-channel noise vocoder. An overall positive effect on intelligibility of both the repackaging process and of the amount of TFS available to the listener was observed. Furthermore, the benefit associated with the repackaging TC speech depended on the amount of TFS available. The results show TFS contributes significantly to the perception of fast speech even when the overall rhythm/envelope of TC speech is restored.
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Van Herck S, Economou M, Vanden Bempt F, Glatz T, Ghesquière P, Vandermosten M, Wouters J. Neural synchronization and intervention in pre-readers who later on develop dyslexia. Eur J Neurosci 2023; 57:547-567. [PMID: 36518008 PMCID: PMC10108076 DOI: 10.1111/ejn.15894] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/07/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
A growing number of studies has investigated temporal processing deficits in dyslexia. These studies largely focus on neural synchronization to speech. However, the importance of rise times for neural synchronization is often overlooked. Furthermore, targeted interventions, phonics-based and auditory, are being developed, but little is known about their impact. The current study investigated the impact of a 12-week tablet-based intervention. Children at risk for dyslexia received phonics-based training, either with (n = 31) or without (n = 31) auditory training, or engaged in active control training (n = 29). Additionally, neural synchronization and processing of rise times was longitudinally investigated in children with dyslexia (n = 26) and typical readers (n = 52) from pre-reading (5 years) to beginning reading age (7 years). The three time points in the longitudinal study correspond to intervention pre-test, post-test and consolidation, approximately 1 year after completing the intervention. At each time point neural synchronization was measured to sinusoidal stimuli and pulsatile stimuli with shortened rise times at syllable (4 Hz) and phoneme rates (20 Hz). Our results revealed no impact on neural synchronization at syllable and phoneme rate of the phonics-based and auditory training. However, we did reveal atypical hemispheric specialization at both syllable and phoneme rates in children with dyslexia. This was detected even before the onset of reading acquisition, pointing towards a possible causal rather than consequential mechanism in dyslexia. This study contributes to our understanding of the temporal processing deficits underlying the development of dyslexia, but also shows that the development of targeted interventions is still a work in progress.
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Affiliation(s)
- Shauni Van Herck
- Research Group ExpORL, Department of NeurosciencesKU LeuvenLeuvenBelgium
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational SciencesKU LeuvenLeuvenBelgium
- Leuven Brain InstituteKU LeuvenLeuvenBelgium
| | - Maria Economou
- Research Group ExpORL, Department of NeurosciencesKU LeuvenLeuvenBelgium
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational SciencesKU LeuvenLeuvenBelgium
- Leuven Brain InstituteKU LeuvenLeuvenBelgium
- Leuven Child & Youth Institute (L‐C&Y)KU LeuvenLeuvenBelgium
| | - Femke Vanden Bempt
- Research Group ExpORL, Department of NeurosciencesKU LeuvenLeuvenBelgium
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational SciencesKU LeuvenLeuvenBelgium
- Leuven Brain InstituteKU LeuvenLeuvenBelgium
- Leuven Child & Youth Institute (L‐C&Y)KU LeuvenLeuvenBelgium
| | - Toivo Glatz
- Research Group ExpORL, Department of NeurosciencesKU LeuvenLeuvenBelgium
- Institute of Public HealthCharité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
| | - Pol Ghesquière
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational SciencesKU LeuvenLeuvenBelgium
- Leuven Brain InstituteKU LeuvenLeuvenBelgium
- Leuven Child & Youth Institute (L‐C&Y)KU LeuvenLeuvenBelgium
| | - Maaike Vandermosten
- Research Group ExpORL, Department of NeurosciencesKU LeuvenLeuvenBelgium
- Leuven Brain InstituteKU LeuvenLeuvenBelgium
- Leuven Child & Youth Institute (L‐C&Y)KU LeuvenLeuvenBelgium
| | - Jan Wouters
- Research Group ExpORL, Department of NeurosciencesKU LeuvenLeuvenBelgium
- Leuven Brain InstituteKU LeuvenLeuvenBelgium
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Vanden Bempt F, Van Herck S, Economou M, Vanderauwera J, Vandermosten M, Wouters J, Ghesquière P. Speech perception deficits and the effect of envelope-enhanced story listening combined with phonics intervention in pre-readers at risk for dyslexia. Front Psychol 2022; 13:1021767. [PMID: 36389538 PMCID: PMC9650384 DOI: 10.3389/fpsyg.2022.1021767] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/12/2022] [Indexed: 11/28/2022] Open
Abstract
Developmental dyslexia is considered to be most effectively addressed with preventive phonics-based interventions, including grapheme-phoneme coupling and blending exercises. These intervention types require intact speech perception abilities, given their large focus on exercises with auditorily presented phonemes. Yet some children with (a risk for) dyslexia experience problems in this domain due to a poorer sensitivity to rise times, i.e., rhythmic acoustic cues present in the speech envelope. As a result, the often subtle speech perception problems could potentially constrain an optimal response to phonics-based interventions in at-risk children. The current study therefore aimed (1) to extend existing research by examining the presence of potential speech perception deficits in pre-readers at cognitive risk for dyslexia when compared to typically developing peers and (2) to explore the added value of a preventive auditory intervention for at-risk pre-readers, targeting rise time sensitivity, on speech perception and other reading-related skills. To obtain the first research objective, we longitudinally compared speech-in-noise perception between 28 5-year-old pre-readers with and 30 peers without a cognitive risk for dyslexia during the second half of the third year of kindergarten. The second research objective was addressed by exploring growth in speech perception and other reading-related skills in an independent sample of 62 at-risk 5-year-old pre-readers who all combined a 12-week preventive phonics-based intervention (GraphoGame-Flemish) with an auditory story listening intervention. In half of the sample, story recordings contained artificially enhanced rise times (GG-FL_EE group, n = 31), while in the other half, stories remained unprocessed (GG-FL_NE group, n = 31; Clinical Trial Number S60962—https://www.uzleuven.be/nl/clinical-trial-center). Results revealed a slower speech-in-noise perception growth in the at-risk compared to the non-at-risk group, due to an emerged deficit at the end of kindergarten. Concerning the auditory intervention effects, both intervention groups showed equal growth in speech-in-noise perception and other reading-related skills, suggesting no boost of envelope-enhanced story listening on top of the effect of combining GraphoGame-Flemish with listening to unprocessed stories. These findings thus provide evidence for a link between speech perception problems and dyslexia, yet do not support the potential of the auditory intervention in its current form.
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Affiliation(s)
- Femke Vanden Bempt
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
- *Correspondence: Femke Vanden Bempt,
| | - Shauni Van Herck
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Maria Economou
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Jolijn Vanderauwera
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
- Psychological Sciences Research Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
- Institute of Neuroscience, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Maaike Vandermosten
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Jan Wouters
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Pol Ghesquière
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
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Goswami U. Language acquisition and speech rhythm patterns: an auditory neuroscience perspective. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211855. [PMID: 35911192 PMCID: PMC9326295 DOI: 10.1098/rsos.211855] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
All human infants acquire language, but their brains do not know which language/s to prepare for. This observation suggests that there are fundamental components of the speech signal that contribute to building a language system, and fundamental neural processing mechanisms that use these components, which are shared across languages. Equally, disorders of language acquisition are found across all languages, with the most prevalent being developmental language disorder (approx. 7% prevalence), where oral language comprehension and production is atypical, and developmental dyslexia (approx. 7% prevalence), where written language acquisition is atypical. Recent advances in auditory neuroscience, along with advances in modelling the speech signal from an amplitude modulation (AM, intensity or energy change) perspective, have increased our understanding of both language acquisition and these developmental disorders. Speech rhythm patterns turn out to be fundamental to both sensory and neural linguistic processing. The rhythmic routines typical of childcare in many cultures, the parental practice of singing lullabies to infants, and the ubiquitous presence of BabyTalk (infant-directed speech) all enhance the fundamental AM components that contribute to building a linguistic brain.
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Affiliation(s)
- Usha Goswami
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge, UK
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Mandke K, Flanagan S, Macfarlane A, Gabrielczyk F, Wilson A, Gross J, Goswami U. Neural sampling of the speech signal at different timescales by children with dyslexia. Neuroimage 2022; 253:119077. [PMID: 35278708 DOI: 10.1016/j.neuroimage.2022.119077] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 01/15/2022] [Accepted: 03/07/2022] [Indexed: 01/08/2023] Open
Abstract
Phonological difficulties characterize individuals with dyslexia across languages. Currently debated is whether these difficulties arise from atypical neural sampling of (or entrainment to) auditory information in speech at slow rates (<10 Hz, related to speech rhythm), faster rates, or neither. MEG studies with adults suggest that atypical sampling in dyslexia affects faster modulations in the neurophysiological gamma band, related to phoneme-level representation. However, dyslexic adults have had years of reduced experience in converting graphemes to phonemes, which could itself cause atypical gamma-band activity. The present study was designed to identify specific linguistic timescales at which English children with dyslexia may show atypical entrainment. Adopting a developmental focus, we hypothesized that children with dyslexia would show atypical entrainment to the prosodic and syllable-level information that is exaggerated in infant-directed speech and carried primarily by amplitude modulations <10 Hz. MEG was recorded in a naturalistic story-listening paradigm. The modulation bands related to different types of linguistic information were derived directly from the speech materials, and lagged coherence at multiple temporal rates spanning 0.9-40 Hz was computed. Group differences in lagged speech-brain coherence between children with dyslexia and control children were most marked in neurophysiological bands corresponding to stress and syllable-level information (<5 Hz in our materials), and phoneme-level information (12-40 Hz). Functional connectivity analyses showed network differences between groups in both hemispheres, with dyslexic children showing significantly reduced global network efficiency. Global network efficiency correlated with dyslexic children's oral language development and with control children's reading development. These developmental data suggest that dyslexia is characterized by atypical neural sampling of auditory information at slower rates. They also throw new light on the nature of the gamma band temporal sampling differences reported in MEG dyslexia studies with adults.
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Affiliation(s)
- Kanad Mandke
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom.
| | - Sheila Flanagan
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Annabel Macfarlane
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Fiona Gabrielczyk
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Angela Wilson
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Joachim Gross
- Institute for Biomagnetism and Biosignal Analysis, University of Münster, Münster, Germany
| | - Usha Goswami
- Centre for Neuroscience in Education, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
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Vanden Bempt F, Economou M, Van Herck S, Vanderauwera J, Glatz T, Vandermosten M, Wouters J, Ghesquière P. Digital Game-Based Phonics Instruction Promotes Print Knowledge in Pre-Readers at Cognitive Risk for Dyslexia. Front Psychol 2021; 12:720548. [PMID: 34566803 PMCID: PMC8455992 DOI: 10.3389/fpsyg.2021.720548] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/13/2021] [Indexed: 11/13/2022] Open
Abstract
Dyslexia is targeted most effectively when (1) interventions are provided preventively, before the onset of reading instruction, and (2) remediation programs combine letter-sound training with phoneme blending. Given the growing potential of technology in educational contexts, there has been a considerable increase of letter-sound trainings embedded in digital serious games. One such intervention is GraphoGame. Yet, current evidence on the preventive impact of GraphoGame is limited by the lack of adaptation of the original learning content to the skills of pre-readers, short training duration, and a restricted focus on explicitly trained skills. Therefore, the current study aims at investigating the impact of a preventive, and pre-reading adapted GraphoGame training (i.e., GraphoGame-Flemish, GG-FL) on explicitly trained skills and non-specifically trained phonological and language abilities. Following a large-scale screening (N = 1225), the current study included 88 pre-reading kindergarteners at cognitive risk for dyslexia who were assigned to three groups training either with GG-FL (n = 31), an active control game (n = 29), or no game (n = 28). Before and after the 12-week intervention, a variety of reading-related skills were assessed. Moreover, receptive letter knowledge and phonological awareness were measured every three weeks during the intervention period. Results revealed significantly larger improvements in the GG-FL group on explicitly trained skills, i.e., letter knowledge and word decoding, without finding transfer-effects to untrained phonological and language abilities. Our findings imply a GG-FL-driven head start on early literacy skills in at-risk children. A follow-up study should uncover the long-term impact and the ability of GG-FL to prevent actual reading failure.
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Affiliation(s)
- Femke Vanden Bempt
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Maria Economou
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Shauni Van Herck
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Jolijn Vanderauwera
- Psychological Sciences Research Institute, Université Catholique de Louvain, Ottignies-Louvain-la-Neuve, Belgium
- Institute of Neuroscience, Université Catholique de Louvain, Ottignies-Louvain-la-Neuve, Belgium
| | - Toivo Glatz
- Institute of Public Health, Charité – Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Maaike Vandermosten
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Jan Wouters
- Research Group ExpORL, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Pol Ghesquière
- Parenting and Special Education Research Unit, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium
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