Modulation of Rolandic Beta-Band Oscillations during Motor Simulation of Joint Actions

Successful joint actions require precise temporal and spatial coordination between individuals who aim to achieve a common goal. A growing number of behavioral data suggest that to efficiently couple and coordinate a joint task, the actors have to represent both own and the partner’s actions. However it is unclear how the motor system is specifically recruited for joint actions. To find out how the goal and the presence of the partner’s hand can impact the motor activity during joint action, we assessed the functional state of 16 participants’ motor cortex during observation and associated motor imagery of joint actions, individual actions, and non-goal-directed actions performed with either 1 or 2 hands. As an indicator of the functional state of the motor cortex, we used the reactivity of the rolandic magnetoencephalographic (MEG) beta rhythm following median-nerve stimulation. Motor imagery combined with action observation was associated with activation of the observer’s motor cortex, mainly in the hemisphere contralateral to the viewed (and at the same time imagined) hand actions. The motor-cortex involvement was enhanced when the goal of the actions was visible but also, in the ipsilateral hemisphere, when the partner’s hand was visible in the display. During joint action, the partner’s action, in addition to the participant’s own action, thus seems to be represented in the motor cortex so that it can be triggered by the mere presence of an acting hand in the peripersonal space.Peer reviewe

Theta oscillations mediate preactivation of highly expected word initial phonemes

Published: 22 June 2018Prediction has been proposed to be a fundamental neurocognitive mechanism. However, its role in language comprehension is currently under debate. In this magnetoencephalography study we aimed to find evidence of word-form phonological pre-activation and to characterize the oscillatory mechanisms supporting this. Participants were presented firstly with a picture of an object, and then, after a delay (fixed or variable), they heard the corresponding word. Target words could contain a phoneme substitution, and participants’ task was to detect mispronunciations. Word-initial phonemes were either fricatives or plosives, generating two experimental conditions (expect-fricative and expect-plosive). In the pre-word interval, significant differences (α = 0.05) emerged between conditions both for fixed and variable delays. Source reconstruction of this effect showed a brain-wide network involving several frequency bands, including bilateral superior temporal areas commonly associated with phonological processing, in a theta range. These results show that phonological representations supported by the theta band may be active before word onset, even under temporal uncertainty. However, in the evoked response just prior to the word, differences between conditions were apparent under variable- but not fixed-delays. This suggests that additional top-down mechanisms sensitive to phonological form may be recruited when there is uncertainty in the signal.This work was partially supported by the Spanish Ministry of Economy and Competitiveness (MINECO), the Agencia Estatal de Investigación (AEI), the Fondo Europeo de Desarrollo Regional FEDER) (grant PSI2016– 77175-P to Mathieu Bourguignon, grant PSI2015–65694-P to Nicola Molinaro, Severo Ochoa programme SEV-2015–490 for Centres of Excellence in R&D), and by the Basque government (grant PI_2016_1_0014 to Nicola Molinaro). Further support derived from the AThEME project funded by the European Commission 7th Framework Programme, the ERC- 2011-ADG-295362 from the European Research Council. Finally, Mathieu Bourguignon was supported by the program Attract of Innoviris (grant 2015-BB2B-10) and by the Marie Skłodowska-Curie Action of the European Commission (grant 743562)

Localization accuracy of a common beamformer for the comparison of two conditions

Available online 23 January 2021.The linearly constrained minimum variance beamformer is frequently used to reconstruct sources underpinning neuromagnetic recordings. When reconstructions must be compared across conditions, it is considered good prac- tice to use a single, “common ”beamformer estimated from all the data at once. This is to ensure that differences between conditions are not ascribable to differences in beamformer weights. Here, we investigate the localiza- tion accuracy of such a common beamformer. Based on theoretical derivations, we first show that the common beamformer leads to localization errors in source reconstruction. We then turn to simulations in which we at- tempt to reconstruct a (genuine) source in a first condition, while considering a second condition in which there is an (interfering) source elsewhere in the brain. We estimate maps of mislocalization and assess statistically the difference between “standard ”and “common ”beamformers. We complement our findings with an application to experimental MEG data. The results show that the common beamformer may yield significant mislocalization. Specifically, the common beamformer may force the genuine source to be reconstructed closer to the interfering source than it really is. As the same applies to the reconstruction of the interfering source, both sources are pulled closer together than they are. This observation was further illustrated in experimental data. Thus, although the common beamformer allows for the comparison of conditions, in some circumstances it introduces localization inaccuracies. We recommend alternative approaches to the general problem of comparing conditions.G.L.G. was supported by postdoctoral grant from FNRS-FWO Excel- lence Of Science project Memodyn (ID EOS 30446199). M.B. has been supported by the program Attract of Innoviris (grant 2015-BB2B-10), by the Spanish Ministry of Economy and Competitiveness (grant PSI2016- 77175-P), and by the Marie Sklodowska-Curie Action of the European Commission (grant 743562). This study and the MEG project at CUB Hôpital Erasme were financially supported by the Fonds Erasme (Re- search Convention: “Les Voies du Savoir ”, Fonds Erasme, Brussels, Bel- gium)

Sensorimotor Mapping With MEG: An Update on the Current State of Clinical Research and Practice With Considerations for Clinical Practice Guidelines

Published: November 2020In this article, we present the clinical indications and advances in the use of magnetoencephalography to map the primary sensorimotor (SM1) cortex in neurosurgical patients noninvasively. We emphasize the advantages of magnetoencephalography over sensorimotor mapping using functional magnetic resonance imaging. Recommendations to the referring physicians and the clinical magnetoencephalographers to achieve appropriate sensorimotor cortex mapping using magnetoencephalography are proposed. We finally provide some practical advice for the use of corticomuscular coherence, corticokinematic coherence, and mu rhythm suppression in this indication. Magnetoencephalography should now be considered as a method of reference for presurgical functional mapping of the sensorimotor cortex.X. De Ti ege is Post-doctorate Clinical Master Specialist at the Fonds de la Recherche Scientifique (FRS-FNRS, Brussels, Belgium). M. Bourguignon has been supported by the program Attract of Innoviris (Grant 2015-BB2B-10), by the Spanish Ministry of Economy and Competitiveness (Grant PSI2016- 77175-P), and by the Marie Sk1odowska-Curie Action of the European Commission (Grant 743562). H. Piitulainen has been supported by the Academy of Finland (Grants #266133 and #296240), the Jane and Aatos Erkko Foundation, and the Emil Aaltonen Foundation. The authors thank Professor Riitta Hari for her support in most of the research works published by the authors and presented in this article. The MEG project at the CUB H^opital Erasme is financially supported by the Fonds Erasme (Research convention “Les Voies du Savoir,” Fonds Erasme, Brussels, Belgium)

Amodal Atypical Neural Oscillatory Activity in Dyslexia: A Cross-Linguistic Perspective

First Published December 21, 2016It has been proposed that atypical neural oscillations in both the auditory and the visual modalities could explain why some individuals fail to learn to read and suffer from developmental dyslexia. However, the role of specific oscillatory mechanisms in reading acquisition is still under debate. In this article, we take a cross-linguistic approach and argue that both the phonological and orthographic specifics of a language (e.g., linguistic rhythm, orthographic depth) shape the oscillatory activity thought to contribute to reading development. The proposed theoretical framework should allow future research to test cross-linguistic hypotheses that will shed light on the heterogeneity of auditory and visual disorders and their underlying brain dysfunction(s) in developmental dyslexia, and inform clinical practice by helping us to diagnose dyslexia across languages.This research was funded by the European Research Council (ERC Advanced Grant, BILITERACY Project, to M.C.), and the Spanish government (Plan Nacional-PSI2012-32128 and PSI2015-65338-P to M.L., Plan Nacional-PSI2012-32350 and PSI2015-65694-P to N.M., and Plan Nacional-PSI2015-67353-R to M.C.). The Basque Center on Brain Cognition and Language acknowledges funding from Ayuda Centro de Excelencia Severo Ochoa SEV-2015-0490

Two Cheers for Ritual:The UN Committee Against Torture

Fraipontite is a very rare mineral described by Cesàro and found in the Vieille Montagne mines, eastern Belgium. The morphology, observed by scanning electron microscope, especially shows a lamellar structure. Optical data are : Ng = Nm = 1.624 and (—) 2 V = 15-20°. The X-ray powder pattern is given and index for a monoclinic unit cell with a = 5.372, b = 9.246, c = 7.273 Å and β = 103°33'. A new chemical analysis, completed with microprobe outline, is compared with previous data. The phase changes are identified by X-ray diffraction after heating ; so, zincite, willemite and gahnite successively appear after destruction of fraipontite near 425° C. Thermal and infrared analyses show the presence of hygroscopic water and suggest a crystallochemical formula : (Zn₂.₃₅Al₀.₆₅) (Si₁.₃₅Al₀.₆₅) O₅ (OH)₄. All these data strengthen the position of fraipontite as a real species, for a natural zinc-bearing berthierine.Découverte par Cesàro, la fraipontite est un minéral très rare provenant des mines de la Vieille Montagne, dans l'est de la Belgique. La morphologie observée au microscope électronique à balayage révèle principalement une structure feuilletée. L'analyse optique fournit Ng = Nm = 1,624 et (—) 2 V = 15-20°. Le diagramme de poudre est donné avec une indexation qui conduit aux paramètres d'une maille monoclinique : a = 5,372, b = 9,246, c = 7,273 Å et β = 103°33'. Une nouvelle analyse chimique, complétée par des examens à la microsonde électronique, est comparée aux données antérieures. Les changements de phases, examinés par diffraction des rayons X après chauffage, conduisent, après destruction de la fraipontite vers 425° C, à l'apparition de zincite, willémite et gahnite. L'étude thermique et l'analyse par spectroscopie infrarouge montrent la présence d'eau hygroscopique et permettent de déduire une formule cristallochimique : (Zn₂,₃₅Al₀,₆₅) (Si₁,₃₅Al₀,₆₅) O₅ (OH)₄. L'ensemble de ces données renforce la position de la fraipontite en tant qu'espèce, désignant une berthiérine zincifère naturelle.Fransolet André-Mathieu, Bourguignon Pol. Données nouvelles sur la fraipontite de Moresnet (Belgique). In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 98, 4, 1975. pp. 235-244

Corticokinematic coherence as a new marker for somatosensory afference in newborns

Objective: Somatosensory evoked potentials have high prognostic value in neonatal intensive care, but their recording from infants is challenging. Here, we studied the possibility to elicit cortical responses in newborns by simple passive hand movements. Methods: We examined 13 newborns (postnatal age 1-46 days) during clinically indicated 19-channel electroencephalography (EEG) recordings in the neonatal intensive care unit; EEG indications included birth asphyxia and suspected epileptic seizures. The experimenter moved the infant's wrist or fingers at 1 or 2 Hz for 5-10 min, separately on both sides. We measured movement kinematics with an accelerometer attached to the infant's hand and computed coherence between the EEG and acceleration signals (corticokinematic coherence, CKC). Results: Statistically significant CKC (amplitude 0.020-0.511) with characteristic scalp topography was observed in all infants at twice the movement frequency. CKC was contralaterally dominant on the central scalp (median laterality index 0.48 for right-hand and -0.63 for left-hand movements). Conclusions: Passive movements elicit cortical responses that can be readily observed in clinical EEG recordings from newborns in the intensive-care environment. (C) 2017 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd.Peer reviewe

Speech‑derived haptic stimulation enhances speech recognition in a multi‑talker background

Published: 03 October 2023Speech understanding, while effortless in quiet conditions, is challenging in noisy environments. Previous studies have revealed that a feasible approach to supplement speech-in-noise (SiN) perception consists in presenting speech-derived signals as haptic input. In the current study, we investigated whether the presentation of a vibrotactile signal derived from the speech temporal envelope can improve SiN intelligibility in a multi-talker background for untrained, normal-hearing listeners. We also determined if vibrotactile sensitivity, evaluated using vibrotactile detection thresholds, modulates the extent of audio-tactile SiN improvement. In practice, we measured participants’ speech recognition in a multi-talker noise without (audio-only) and with (audio-tactile) concurrent vibrotactile stimulation delivered in three schemes: to the left or right palm, or to both. Averaged across the three stimulation delivery schemes, the vibrotactile stimulation led to a significant improvement of 0.41 dB in SiN recognition when compared to the audio-only condition. Notably, there were no significant differences observed between the improvements in these delivery schemes. In addition, audio-tactile SiN benefit was significantly predicted by participants’ vibrotactile threshold levels and unimodal (audio-only) SiN performance. The extent of the improvement afforded by speech-envelope-derived vibrotactile stimulation was in line with previously uncovered vibrotactile enhancements of SiN perception in untrained listeners with no known hearing impairment. Overall, these results highlight the potential of concurrent vibrotactile stimulation to improve SiN recognition, especially in individuals with poor SiN perception abilities, and tentatively more so with increasing tactile sensitivity. Moreover, they lend support to the multimodal accounts of speech perception and research on tactile speech aid devices.I. Sabina Răutu is supported by the Fonds pour la formation à la recherche dans l’industrie et l’agriculture (FRIA), Fonds de la Recherche Scientifique (FRS-FNRS), Brussels, Belgium. Xavier De Tiège is Clinical Researcher at the FRS-FNRS. This research project has been supported by the Fonds Erasme (Research convention “Les Voies du Savoir 2”, Brussels, Belgium)

Altered neocortical tactile but preserved auditory early change detection responses in Friedreich ataxia

Available online 11 May 2019Objective: To study using magnetoencephalography (MEG) the spatio-temporal dynamics of neocortical responses involved in sensory processing and early change detection in Friedreich ataxia (FRDA). Methods: Tactile (TERs) and auditory (AERs) evoked responses, and early neocortical change detection responses indexed by the mismatch negativity (MMN) were recorded using tactile and auditory oddballs in sixteen FRDA patients and matched healthy subjects. Correlations between the maximal amplitude of each response, genotype and clinical parameters were investigated. Results: Evoked responses were detectable in all FRDA patients but one. In patients, TERs were delayed and reduced in amplitude, while AERs were only delayed. Only tactile MMN responses at the contralateral secondary somatosensory cortex were altered in FRDA patients. Maximal amplitudes of TERs, AERs and tactile MMN correlated with genotype, but did not correlate with clinical parameters. Conclusions: In FRDA, the amplitude of tactile MMN responses at SII cortex are reduced and correlate with the genotype, while auditory MMN responses are not altered. Significance: Somatosensory pathways and tactile early change detection are selectively impaired in FRDAThis study was financially supported by (i) the research grant ‘‘Les Voies du Savoir” from the Fonds Erasme (Brussels, Belgium) and (ii) the Fonds de la Recherche Scientifique (FRS-FNRS, Brussels, Belgium; research credit: J.0095.16.F). Gilles Naeije was supported by a research grant from the Fonds Erasme (Brussels, Belgium). Mathieu Bourguignon was supported by the program Attract of Innoviris (grant 2015-BB2B-10), by the Spanish Ministry of Economy and Competitiveness (grant PSI2016-77175-P), and by the Marie Skłodowska-Curie Action of the European Commission (grant 743562). Xavier De Tiège is Postdoctorate Clinical Master Specialist at the Fonds de la Recherche Scientifique (FRS-FNRS, Brussels, Belgium). The MEG project at the CUB Hôpital Erasme is financially supported by the Fonds Erasme (Research grant ‘‘Les Voies du Savoir”, Brussels, Belgium). The authors would like to thank Brice Marty for his help in MEG data acquisition

Cortical tracking of lexical speech units in a multi-talker background is immature in school-aged children

Available online 1 December 2022Children have more difficulty perceiving speech in noise than adults. Whether this difficulty relates to an immature processing of prosodic or linguistic elements of the attended speech is still unclear. To address the impact of noise on linguistic processing per se, we assessed how babble noise impacts the cortical tracking of intelligible speech devoid of prosody in school-aged children and adults. Twenty adults and twenty children (7-9 years) listened to synthesized French monosyllabic words presented at 2.5 Hz, either randomly or in 4-word hierarchical structures wherein 2 words formed a phrase at 1.25 Hz, and 2 phrases formed a sentence at 0.625 Hz, with or without babble noise. Neuromagnetic responses to words, phrases and sentences were identified and source-localized. Children and adults displayed significant cortical tracking of words in all conditions, and of phrases and sentences only when words formed meaningful sentences. In children compared with adults, the cortical tracking was lower for all linguistic units in conditions without noise. In the presence of noise, the cortical tracking was similarly reduced for sentence units in both groups, but remained stable for phrase units. Critically, when there was noise, adults increased the cortical tracking of monosyllabic words in the inferior frontal gyri and supratemporal auditory cortices but children did not. This study demonstrates that the difficulties of school-aged children in understanding speech in a multi-talker background might be partly due to an immature tracking of lexical but not supra-lexical linguistic units.Maxime Niesen and Marc Vander Ghinst were supported by the Fonds Erasme (Brussels, Belgium). Mathieu Bourguignon and Julie Ber- tels have been supported by the program Attract of Innoviris (grants 2015-BB2B-10 and 2019-BFB-110). Julie Bertels has been supported by a research grant from the Fonds de Soutien Marguerite-Marie Delacroix (Brussels, Belgium). Xavier De Tiège is Clinical Researcher at the Fonds de la Recherche Scientifique (FRS-FNRS, Brussels, Belgium). We warmly thank Mélina Houinsou Hans for her statistical support during the re- view process