Automatic cortical representation of auditory pitch changes in Rett syndrome / J. J. FOXE in Journal of Neurodevelopmental Disorders, 8-1 (December 2016)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 8-1 (December 2016) . - p.34 Titre : Automatic cortical representation of auditory pitch changes in Rett syndrome Type de document : Texte imprimé et/ou numérique Auteurs : J. J. FOXE, Auteur ; K. M. BURKE, Auteur ; G. N. ANDRADE, Auteur ; A. DJUKIC, Auteur ; H. P. FREY, Auteur ; S. MOLHOLM, Auteur Article en page(s) : p.34 Langues : Anglais (eng) Mots-clés : Aep  Auditory evoked potential  Eeg  Erp  Event-related potential  Females  High-density electrical mapping  Mecp2  Mmn  Mismatch negativity Index. décimale : PER Périodiques Résumé : BACKGROUND: Over the typical course of Rett syndrome, initial language and communication abilities deteriorate dramatically between the ages of 1 and 4 years, and a majority of these children go on to lose all oral communication abilities. It becomes extremely difficult for clinicians and caretakers to accurately assess the level of preserved auditory functioning in these children, an issue of obvious clinical import. Non-invasive electrophysiological techniques allow for the interrogation of auditory cortical processing without the need for overt behavioral responses. In particular, the mismatch negativity (MMN) component of the auditory evoked potential (AEP) provides an excellent and robust dependent measure of change detection and auditory sensory memory. Here, we asked whether females with Rett syndrome would produce the MMN to occasional changes in pitch in a regularly occurring stream of auditory tones. METHODS: Fourteen girls with genetically confirmed Rett syndrome and 22 age-matched neurotypical controls participated (ages 3.9-21.1 years). High-density electrophysiological recordings from 64 scalp electrodes were made while participants passively listened to a regularly occurring stream of 503-Hz auditory tone pips that was occasionally (15 % of presentations) interrupted by a higher-pitched deviant tone of 996 Hz. The MMN was derived by subtracting the AEP to these deviants from the AEP produced to the standard. RESULTS: Despite clearly anomalous morphology and latency of the AEP to simple pure-tone inputs in Rett syndrome, the MMN response was evident in both neurotypicals and Rett patients. However, we found that the pitch-evoked MMN was both delayed and protracted in duration in Rett, pointing to slowing of auditory responsiveness. CONCLUSIONS: The presence of the MMN in Rett patients suggests preserved abilities to process pitch changes in auditory sensory memory. This work represents a beginning step in an effort to comprehensively map the extent of auditory cortical functioning in Rett syndrome. These easily obtained objective brain measures of auditory processing have promise as biomarkers against which future therapeutic efforts can be assayed. En ligne : http://dx.doi.org/10.1186/s11689-016-9166-5 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=349 [article] Automatic cortical representation of auditory pitch changes in Rett syndrome [Texte imprimé et/ou numérique] / J. J. FOXE, Auteur ; K. M. BURKE, Auteur ; G. N. ANDRADE, Auteur ; A. DJUKIC, Auteur ; H. P. FREY, Auteur ; S. MOLHOLM, Auteur . - p.34. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 8-1 (December 2016) . - p.34 Mots-clés : Aep  Auditory evoked potential  Eeg  Erp  Event-related potential  Females  High-density electrical mapping  Mecp2  Mmn  Mismatch negativity Index. décimale : PER Périodiques Résumé : BACKGROUND: Over the typical course of Rett syndrome, initial language and communication abilities deteriorate dramatically between the ages of 1 and 4 years, and a majority of these children go on to lose all oral communication abilities. It becomes extremely difficult for clinicians and caretakers to accurately assess the level of preserved auditory functioning in these children, an issue of obvious clinical import. Non-invasive electrophysiological techniques allow for the interrogation of auditory cortical processing without the need for overt behavioral responses. In particular, the mismatch negativity (MMN) component of the auditory evoked potential (AEP) provides an excellent and robust dependent measure of change detection and auditory sensory memory. Here, we asked whether females with Rett syndrome would produce the MMN to occasional changes in pitch in a regularly occurring stream of auditory tones. METHODS: Fourteen girls with genetically confirmed Rett syndrome and 22 age-matched neurotypical controls participated (ages 3.9-21.1 years). High-density electrophysiological recordings from 64 scalp electrodes were made while participants passively listened to a regularly occurring stream of 503-Hz auditory tone pips that was occasionally (15 % of presentations) interrupted by a higher-pitched deviant tone of 996 Hz. The MMN was derived by subtracting the AEP to these deviants from the AEP produced to the standard. RESULTS: Despite clearly anomalous morphology and latency of the AEP to simple pure-tone inputs in Rett syndrome, the MMN response was evident in both neurotypicals and Rett patients. However, we found that the pitch-evoked MMN was both delayed and protracted in duration in Rett, pointing to slowing of auditory responsiveness. CONCLUSIONS: The presence of the MMN in Rett patients suggests preserved abilities to process pitch changes in auditory sensory memory. This work represents a beginning step in an effort to comprehensively map the extent of auditory cortical functioning in Rett syndrome. These easily obtained objective brain measures of auditory processing have promise as biomarkers against which future therapeutic efforts can be assayed. En ligne : http://dx.doi.org/10.1186/s11689-016-9166-5 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=349

Saccade adaptation deficits in developmental dyslexia suggest disruption of cerebellar-dependent learning / E. G. FREEDMAN in Journal of Neurodevelopmental Disorders, 9-1 (December 2017)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 9-1 (December 2017) . - p.36 Titre : Saccade adaptation deficits in developmental dyslexia suggest disruption of cerebellar-dependent learning Type de document : Texte imprimé et/ou numérique Auteurs : E. G. FREEDMAN, Auteur ; S. MOLHOLM, Auteur ; M. J. GRAY, Auteur ; D. BELYUSAR, Auteur ; J. J. FOXE, Auteur Article en page(s) : p.36 Langues : Anglais (eng) Mots-clés : Adaptation  Cerebellum  Dyslexia  Eye movements  Reading  Saccades Index. décimale : PER Périodiques Résumé : BACKGROUND: Estimates of the prevalence of developmental dyslexia in the general population range from 5% to as many as 10%. Symptoms include reading, writing, and language deficits, but the severity and mix of symptoms can vary widely across individuals. In at least some people with dyslexia, the structure and function of the cerebellum may be disordered. Saccadic adaptation requires proper function of the cerebellum and brainstem circuitry and might provide a simple, noninvasive assay for early identification and sub-phenotyping in populations of children who may have dyslexia. METHODS: Children between the ages of 7 and 15 served as participants in this experiment. Fifteen had been diagnosed with developmental dyslexia and an additional 15 were typically developing children. Five of the participants diagnosed with dyslexia were also diagnosed with an attention deficit hyperactivity disroder and were excluded from further analyses. Participants performed in a saccadic adaptation task in which visual errors were introduced at the end of saccadic eye movements. The amplitudes of primary saccades were measured and plotted as a function of the order in which they occurred. Lines of best fit were calculated. Significant changes in the amplitude of primary saccades were identified. RESULTS: 12/15 typically developing children had significant adaptation of saccade amplitude in this experiment. 1/10 participants with dyslexia appropriately altered saccade amplitudes to reduce the visual error introduced in the saccade adaptation paradigm. CONCLUSIONS: Proper cerebellar function is required for saccadic adaptation, but in at least some children with dyslexia, cerebellar structure and function may be disordered. Consistent with this hypothesis, the data presented in this report clearly illustrate a difference in the ability of children with dyslexia to adapt saccade amplitudes in response to imposed visual errors. Saccadic adaptation might provide a noninvasive assay for early identification of dyslexia. Future work will determine whether reduced saccadic adaptation is pervasive in dyslexia or whether this identifies a sub-phenotype within the larger population of people identified with reading and language deficits. En ligne : http://dx.doi.org/10.1186/s11689-017-9218-5 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=350 [article] Saccade adaptation deficits in developmental dyslexia suggest disruption of cerebellar-dependent learning [Texte imprimé et/ou numérique] / E. G. FREEDMAN, Auteur ; S. MOLHOLM, Auteur ; M. J. GRAY, Auteur ; D. BELYUSAR, Auteur ; J. J. FOXE, Auteur . - p.36. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 9-1 (December 2017) . - p.36 Mots-clés : Adaptation  Cerebellum  Dyslexia  Eye movements  Reading  Saccades Index. décimale : PER Périodiques Résumé : BACKGROUND: Estimates of the prevalence of developmental dyslexia in the general population range from 5% to as many as 10%. Symptoms include reading, writing, and language deficits, but the severity and mix of symptoms can vary widely across individuals. In at least some people with dyslexia, the structure and function of the cerebellum may be disordered. Saccadic adaptation requires proper function of the cerebellum and brainstem circuitry and might provide a simple, noninvasive assay for early identification and sub-phenotyping in populations of children who may have dyslexia. METHODS: Children between the ages of 7 and 15 served as participants in this experiment. Fifteen had been diagnosed with developmental dyslexia and an additional 15 were typically developing children. Five of the participants diagnosed with dyslexia were also diagnosed with an attention deficit hyperactivity disroder and were excluded from further analyses. Participants performed in a saccadic adaptation task in which visual errors were introduced at the end of saccadic eye movements. The amplitudes of primary saccades were measured and plotted as a function of the order in which they occurred. Lines of best fit were calculated. Significant changes in the amplitude of primary saccades were identified. RESULTS: 12/15 typically developing children had significant adaptation of saccade amplitude in this experiment. 1/10 participants with dyslexia appropriately altered saccade amplitudes to reduce the visual error introduced in the saccade adaptation paradigm. CONCLUSIONS: Proper cerebellar function is required for saccadic adaptation, but in at least some children with dyslexia, cerebellar structure and function may be disordered. Consistent with this hypothesis, the data presented in this report clearly illustrate a difference in the ability of children with dyslexia to adapt saccade amplitudes in response to imposed visual errors. Saccadic adaptation might provide a noninvasive assay for early identification of dyslexia. Future work will determine whether reduced saccadic adaptation is pervasive in dyslexia or whether this identifies a sub-phenotype within the larger population of people identified with reading and language deficits. En ligne : http://dx.doi.org/10.1186/s11689-017-9218-5 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=350

---

1 (1 - 2 / 2)