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Objectives: This study aimed to evaluate the potential clinical value of a new brain age prediction model as a single interpretable variable representing the condition of our brain. Among many clinical use cases, brain age could be a novel outcome measure to assess the preventive effect of life-style interventions. Methods: The REMEMBER study population (N = 742) consisted of cognitively healthy (HC,N = 91), subjective cognitive decline (SCD,N = 65), mild cognitive impairment (MCI,N = 319) and AD dementia (ADD,N = 267) subjects. Automated brain volumetry of global, cortical, and subcortical brain structures computed by the CE-labeled and FDA-cleared software icobrain dm (dementia) was retrospectively extracted from T1-weighted MRI sequences that were acquired during clinical routine at participating memory clinics from the Belgian Dementia Council. The volumetric features, along with sex, were combined into a weighted sum using a linear model, and were used to predict ‘brain age’ and ‘brain predicted age difference’ (BPAD = brain age–chronological age) for every subject. Results: MCI and ADD patients showed an increased brain age compared to their chronological age. Overall, brain age outperformed BPAD and chronological age in terms of classification accuracy across the AD spectrum. There was a weak-to-moderate correlation between total MMSE score and both brain age (r = -0.38,p <.001) and BPAD (r = -0.26,p <.001). Noticeable trends, but no significant correlations, were found between BPAD and incidence of conversion from MCI to ADD, nor between BPAD and conversion time from MCI to ADD. BPAD was increased in heavy alcohol drinkers compared to non-/sporadic (p =.014) and moderate (p =.040) drinkers. Conclusions: Brain age and associated BPAD have the potential to serve as indicators for, and to evaluate the impact of lifestyle modifications or interventions on, brain health., SCOPUS: ar.j, info:eu-repo/semantics/published

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Understanding speech in the presence of multiple speakers (i.e. cocktail-party scene) is challenging. In such scenarios, research has shown that visual speech cues can improve speech intelligibility, but the extent to which tactile speech input can also provide a beneficial effect remains unclear. In the current study, we present two distinct experiments which evaluated the effect of vibrotactile stimulation on speech perception in cocktail-party noise. Firstly, we measured 46 participants’ speech recognition thresholds in audio-only and audio-tactile noisy conditions. The vibrotactile stimulation, presented congruently (i.e. synchronously) with the speech stream of interest, was provided to the palms either unimanually or bimanually. Secondly, 30 participants listened to four 6-min audio stories which contained speech presented in silence or embedded in noise, with and without additional unimanual vibrotactile stimulation. The vibrotactile input was either congruent or incongruent (i.e. random) with the attended speech. At the end of each story, participants answered comprehension questions related to each experimental condition. The first experiment showed a significant positive effect of vibrotactile stimulation on speech-in-noise recognition, with no significant effect of the stimulation location. The second experiment illustrated a significant effect of congruent vibrotactile stimulation on the percentage of correct responses to comprehension questions. Moreover, it highlighted the absence of a significant enhancing effect when the vibrotactile input is incongruent with the speech signal, as well as in the absence of background noise. Taken together, our results illustrate the potential role of the tactile modality to supplement speech-in-noise perception, even in complex cocktail-party auditory scenes., info:eu-repo/semantics/nonPublished

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In the current study, we investigated whether vibrotactile stimulation derived from the speech temporal envelope can facilitate the neural tracking of speech in normal hearing listeners. Magnetoencephalographic (MEG) activity from 30 French-speaking participants was recorded while they attended to videos of native French speakers reciting stories with neutral content. The heard audio was presented either in silence or embedded in multi-talker noise, with (Audiotactile [AT] condition) or without (Audio-only [A] condtion) vibrotactile stimulation. During the AT conditions, vibrotactile envelope-based stimulation was delivered to the participants’ left palm either congruently (i.e. in synchrony) or incongruently with the speech signal of the attended speaker. Neural tracking was then assessed per condition using speech-brain coherence at the phrasal and syllabic levels (0.2 – 1.5 Hz and 2 – 8 Hz, respectively). Results indicate a robust enhancing effect of the congruent vibrotactile stimulation on the neural tracking of speech. This vibrotactile benefit was present at the syllabic-level tracking, and was significantly more pronounced in the right hemisphere. Moreover, the effect of vibrotactile input was particularly enhanced under noise conditions. Contrastingly, no effect of the vibrotactile stimulation was found on the neural tracking of speech at the phrasal level. Vibrotactile input also impacted behavioral performance, with comprehension in noise being significantly improved by congruent vibrotactile input compared with audio-only or incongruent vibrotactile conditions. This study provides novel insights into the mechanisms of proven haptic enhancement of speech comprehension in silent and noisy auditory conditions. As such, this offers potential implications in the design of haptic auditory devices., info:eu-repo/semantics/inPress

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It’s difficult not to be amazed by the intricate process through which a honeybee swarm selects anew nest site. By exploring different options and sharing information with one another, the beescan collectively choose a single site. A key feature of these collective decisions is that they arenot directed by a centralized planner, but instead arise entirely from the interactions of individualswith each other and their environment. Inspired by such natural phenomena, roboticists are nowimplementing similar strategies in robot swarms to enhance collective decision-makingAs a social species, humans also frequently make collective decisions. Many important decisionsfor our societies are not made by a single individual but emerge from extensive verbal discussionsbetween multiple individuals. This dissertation aims to build a conceptual and experimentalbridge linking the study of human collective decision making with the more embodied collectivedecision making of animal and robotic swarms, which mostly take place through movements inphysical space. To do so, we place human participants in the type of embodied decision makingscenarios that swarms usually operate in.We created a virtual environment in which large groups of human participants can interact withone another and perform various tasks that are commonly studied in swarm robotics research. Intwo behavioral experiments, we used this virtual environment to study human behavior duringcollective decision making. In the first experiment, we studied how participants can form acollective perception of their environment by each exploring some part of the environment andthen sharing that information. In a subsequent experiment, we study how a group of participantscan select the best site in their environment while only using movement-based communication.The third study presented in this thesis reports on how human participants can implicitly signaltheir confidence in their movements during decision making in a shared physical, Doctorat en Sciences psychologiques et de l'éducation, info:eu-repo/semantics/nonPublished

Visual statistical learning refers to the ability to detect and extract regularities from the environment. Thus far, infancy research has mostly investigated this ability with post-exposure behavioural tasks which only reveal the outcome of learning. Notably, behavioural tasks may lead to ambiguous interpretations since there is no clear consensus about the directionality of the expected learning outcome. Electrophysiological measures such as steady-state visual evoked potentials (SSVEPs) can be acquired while learning occurs and can shed light onto the temporal course of learning. At present, SSVEPs investigations of the ongoing learning processes have been limited to the auditory domain (Choi et al. 2020). In this study, we use SSVEPs to investigate infants’ neural entrainment mechanisms in response to visual regularities. Four- to six-month-old infants were presented with 20 s streams of 8 colourful shapes appearing in the centre of the screen at a frequency of 6 Hz. They were randomly assigned to one of three conditions: 1) standard doublet, in which shapes were organised in 4 doublets, 2) control doublet, in which shapes formed 16 doublets, and 3) random. We compared SSVEPs at the frequency of visual stimulation (6 Hz and its harmonics) and at the doublet frequency (3 Hz and its harmonics) across conditions. If the condition included visual regularities, we hypothesised a progressive response at 3 Hz. Results revealed neural entrainment at the base frequency that did not differ across conditions. This confirmed that infants were similarly attending to the visual stream of stimuli. On the other side, activity at the doublet frequency varied across conditions. Infants assigned to the doublet conditions showed greater responses at the doublet frequency, especially at 9 Hz, compared to the random condition. Overall, these results suggest that the infant brain can detect visual regularities in a stream of shapes from very early on., info:eu-repo/semantics/published

Motor skills dynamically evolve during practice and after training. Using magnetoencephalography, we investigated the neural dynamics underpinning motor learning and its consolidation in relation to sleep during resting-state periods after the end of learning (boost window, within 30 min) and at delayed time scales (silent 4 h and next day 24 h windows) with intermediate daytime sleep or wakefulness. Resting-state neural dynamics were investigated at fast (sub-second) and slower (supra-second) timescales using Hidden Markov modelling (HMM) and functional connectivity (FC), respectively, and their relationship to motor performance. HMM results show that fast dynamic activities in a Temporal/Sensorimotor state network predict individual motor performance, suggesting a trait-like association between rapidly recurrent neural patterns and motor behaviour. Short, post-training task re-exposure modulated neural network characteristics during the boost but not the silent window. Re-exposure-related induction effects were observed on the next day, to a lesser extent than during the boost window. Daytime naps did not modulate memory consolidation at the behavioural and neural levels. These results emphasise the critical role of the transient boost window in motor learning and memory consolidation and provide further insights into the relationship between the multiscale neural dynamics of brain networks, motor learning, and consolidation., SCOPUS: ar.j, info:eu-repo/semantics/published

In this study, we investigated the electrical brain responses in a high-density EEG array (64 electrodes) elicited specifically by the word memory cue in the Think/No-Think paradigm in 46 participants. In a first step, we corroborated previous findings demonstrating sustained and reduced brain electrical frontal and parietal late potentials elicited by memory cues following the No-Think (NT) instructions as compared to the Think (T) instructions. The topographical analysis revealed that such reduction was significant 1000 ms after memory cue onset and that it was long-lasting for 1000 ms. In a second step, we estimated the underlying brain generators with a distributed method (swLORETA) which does not preconceive any localization in the gray matter. This method revealed that the cognitive process related to the inhibition of memory retrieval involved classical motoric cerebral structures with the left primary motor cortex (M1, BA4), thalamus, and premotor cortex (BA6). Also, the right frontal-polar cortex was involved in the T condition which we interpreted as an indication of its role in the maintaining of a cognitive set during remembering, by the selection of one cognitive mode of processing, Think, over the other, No-Think, across extended periods of time, as it might be necessary for the successful execution of the Think/No-Think task., SCOPUS: ar.j, info:eu-repo/semantics/published

AU A subpopulation: Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly of deeply quiescent, so-called dormant hematopoietic :stem cells (dHSCs) resides at the top of the hematopoietic hierarchy and serves as a reserve pool for HSCs. The state of dormancy protects the HSC pool from exhaustion throughout life; however, excessive dormancy may prevent an efficient response to hematological stresses. Despite the significance of dHSCs, the mechanisms maintaining their dormancy remain elusive. Here, we identify CD38 as a novel and broadly applicable surface marker for the enrichment of murine dHSCs. We demonstrate that cyclic adenosine diphosphate ribose (cADPR), the product of CD38 cyclase activity, regulates the expression of the transcription factor c-Fos by increasing the release of Ca2+ from the endoplasmic reticulum (ER). Subsequently, we uncover that c-Fos induces the expression of the cell cycle inhibitor p57Kip2 to drive HSC dormancy. Moreover, we found that CD38 ecto-enzymatic activity at the neighboring CD38-positive cells can promote human HSC quiescence. Together, CD38/cADPR/Ca2+/c-Fos/ p57Kip2 axis maintains HSC dormancy. Pharmacological manipulations of this pathway can provide new strategies to improve the success of stem cell transplantation and blood regeneration after injury or disease., SCOPUS: ar.j, info:eu-repo/semantics/published

Most auditory environments contain multiple sound waves that are mixed before reaching the ears. In such situations, listeners must disentangle individual sounds from the mixture, performing the auditory scene analysis. Analyzing complex auditory scenes relies on listeners ability to segregate acoustic events into different streams, and to selectively attend to the stream of interest. Both segregation and selective attention are known to be challenging for adults with normal hearing, and seem to be even more difficult for children. Here, we review the recent literature on the development of auditory scene analysis, presenting behavioral and neurophysiological results. In short, cognitive and neural mechanisms supporting stream segregation are functional from birth but keep developing until adolescence. Similarly, from 6 months of age, infants can orient their attention toward a target in the presence of distractors. However, selective auditory attention in the presence of interfering streams only reaches maturity in late childhood at the earliest. Methodological limitations are discussed, and a new paradigm is proposed to clarify the relationship between auditory scene analysis and speech perception in noise throughout development., SCOPUS: sh.j, info:eu-repo/semantics/published

Myoelectric prostheses have recently shown significant promise for restoring hand function in individuals with upper limb loss or deficiencies, driven by advances in machine learning and increasingly accessible bioelectrical signal acquisition devices. Here, we first introduce and validate a novel experimental paradigm using a virtual reality headset equipped with hand-tracking capabilities to facilitate the recordings of synchronized EMG signals and hand pose estimation. Using both the phasic and tonic EMG components of data acquired through the proposed paradigm, we compare hand gesture classification pipelines based on standard signal processing features, convolutional neural networks, and covariance matrices with Riemannian geometry computed from raw or xDAWN-filtered EMG signals. We demonstrate the performance of the latter for gesture classification using EMG signals. We further hypothesize that introducing physiological knowledge in machine learning models will enhance their performances, leading to better myoelectric prosthesis control. We demonstrate the potential of this approach by using the neurophysiological integration of the “move command" to better separate the phasic and tonic components of the EMG signals, significantly improving the performance of sustained posture recognition. These results pave the way for the development of new cutting-edge machine learning techniques, likely refined by neurophysiology, that will further improve the decoding of real-time natural gestures and, ultimately, the control of myoelectric prostheses., SCOPUS: ar.j, info:eu-repo/semantics/published

Currently available data indicate that microstructural brain changes underlying motor sequence learning can be evidenced already in the very short term (i.e. less than one hour). Further evidence suggests that post-training sleep contributes to consolidate motor memories, potentially leading to enduring microstructural modifications. Moreover, strengthening a recent memory trace by triggering its (re)processing during sleep is feasible through Targeted Memory Reactivation (TMR), by cueing previously learned material during post-training sleep. Whether TMR leads to additional changes in the brain’s microstructure remains yet to be determined.Ninety young, healthy adults underwent five Diffusion Weighted Imaging (DWI) sessions, participated in two sequential motor trainings, and experienced either a post-training night of total sleep deprivation (SD), regular sleep (RS), or sleep with TMR, spread over five days. We combined standard Diffusion Tensor Imaging (DTI) with Neurite Orientation Dispersion & Density Imaging (NODDI) to assess dendritic and axonal complexity more accurately in grey matter.Significant learning-induced changes were observed across extensive occipitoparietal and temporal regions, as well as in the cerebellar cortex and motor-related subcortical areas such as the thalamus, putamen, and hippocampus. Notably, reductions in Mean Diffusivity (MD) within cortical areas corresponded with decreases in Free Water Fraction (FWF) and increases in Neurite Density Index (NDI). Subcortical regions also showed MD reductions, with FWF reductions observed in all areas except the putamen, which exhibited a marked NDI increase suggesting enhanced neurite density. On day 5, a limited persistence of these learning-induced modifications was noted. A subsequent retraining session elicited noticeable cortical changes, albeit less extensive than those observed during initial learning. At the subcortical level, modifications were detected in the putamen and the thalamus, a, Doctorat en Sciences psychologiques et de l'éducation, info:eu-repo/semantics/nonPublished

We propose a new approach to consciousness science that instead of comparing complex theoretical positions deconstructs existing theories, takes their central assumptions while disregarding their auxiliary hypotheses, and focuses its investigations on the main constructs that these central assumptions rely on (like global workspace, recurrent processing, metarepresentation). Studying how these main constructs are anchored in lower-level constructs characterizing underlying neural processing will not just offer an alternative to theory comparisons but will also take us one step closer to empirical resolutions. Moreover, exploring the compatibility and possible combinations of the lower-level constructs will allow for new theoretical syntheses. This construct-first approach will improve our ability to understand the commitments of existing theories and pave the way for moving beyond them., SCOPUS: re.j, info:eu-repo/semantics/published

The prevalence of obstructive sleep apnea (OSA) among the bariatric surgery population is estimated to be 45–70%. However, weight loss obtained by bariatric surgery is not always associated with full remission of OSA, suggesting that other confounding factors are present. This article aims to review the current literature, focusing on factors that could predict the persistence of OSA after bariatric surgery. For this purpose, relevant studies of more than 50 patients that assessed pre-and post-operative presence and severity of OSA detected by poly(somno)graphy (PG/PSG) in bariatric populations were collected. Six retrospective and prospective studies were evaluated that included 1302 OSA patients, with a BMI range of 42.6 to 56 kg/m2, age range of 44.8 to 50.7 years, and percentage of women ranging from 45% to 91%. The studies were very heterogeneous regarding type of bariatric surgery, diagnostic criteria for OSA and OSA remission, and delay of OSA reassessment. OSA remission was observed in 26% to 76% of patients at 11–12 months post-surgery. Loss to follow-up was high in all studies, leading to a potential underestimation of OSA remission. Based on this limited sample of bariatric patients, age, pre-operative OSA severity, proportion of weight loss, and type 2 diabetes (T2D) were identified as factors associated with OSA persistence but the results were inconsistent between studies regarding the impact of age and the magnitude of weight loss. Several other factors may potentially lead to OSA persistence in the bariatric surgery population, such as fat distribution, ethnicity, anatomical predisposition, pathophysiological traits, supine position, and REM-predominant hypopnea and apnea. Further well-conducted multicentric prospective studies are needed to document the importance of these factors to achieve a better understanding of OSA persistence after bariatric surgery in obese patients., SCOPUS: re.j, info:eu-repo/semantics/published

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Developmental research has mostly investigated statistical learning skills with post-exposure behavioural tasks. These tasks only reveal the outcome of learning and may lead to ambiguous interpretations. Steady-state evoked potentials (SSEPs) can be acquired while learning occurs and can shed light onto the temporal course of learning. At present, SSEPs investigations in this field have been limited to auditory stimuli (Choi et al. 2020). Here we used SSEPs to investigate infants’ neural entrainment in response to visual regularities. Four- to six-month-old infants (N=30) were presented with continuous streams of shapes flashing at 6 Hz. Shapes could be either organised in doublets or randomly presented. We compared SSEPs at the frequency of stimulation (6 Hz and harmonics) and at the doublet frequency (3 Hz and harmonics) across doublet and random presentations. For the doublet organization, we hypothesised a response at 3 Hz and harmonics. Results revealed that neural entrainment at the base frequency did not differ across conditions. On the other hand, infants in the doublet condition showed significantly greater responses at the doublet frequency than those in the random presentation. Overall, frequency tagging appears a promising tool for developmental research and can provide an early neural signature of visual statistical learning., info:eu-repo/semantics/published

Visual statistical learning (VSL) refers to the ability of becoming sensitive to the visual regularities in our environment. This skill facilitates the detection of structure and emerges very early in development (Bulf et al. 2011; Kirkham et al. 2002). Thus far, developmental research has mostly investigated VSL with post-exposure behavioural tasks that only reveal the outcome of learning. Notably, behavioural tasks may lead to ambiguous interpretations since there is no clear consensus about the directionality of the expected learning outcome (i.e. novelty vs. familiarity effect). Steady-state visual evoked potentials (SSVEPs) can be acquired while learning occurs and can shed light onto the temporal course of learning. At present, SSVEPs investigations of the ongoing learning processes have been limited to the auditory domain (Choi et al. 2020). In this study, we used SSVEPs to investigate infants’ neural entrainment mechanisms in response to visual regularities. The final sample included 30 4- to 6-month-old infants (11 females, M age = 156.5 days). Participants were presented with 20s blocks of 8 colourful shapes appearing in the centre of the screen at a frequency of 6 Hz. These blocks were alternated with attention-getting animations to attract the infant attention to the screen. Participants were randomly assigned to one of three conditions: 1) the standard doublet condition, in which the 8 shapes were organised in 4 doublets, 2) the control doublet condition, in which 4 shapes could take the first position of the doublet and other 4 shapes the second position of the doublet, leading in turn to 16 possible doublets, and 3) the random condition, in which individual shapes were randomly presented. We compared the signal-to-noise ratio (SNR) at the base frequency of visual stimulation (6 Hz and its higher harmonics) and at the frequency of doublet presentation (3 Hz and its higher harmonics) across conditions. As long as participants were attending to the visua, Oral presentation in the Symposium “Neural Entrainment as a Gateway to Understanding Infants' Learning skills”, info:eu-repo/semantics/nonPublished

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Which systems/organisms are conscious? New tests for consciousness (‘C-tests’) are urgently needed. There is persisting uncertainty about when consciousness arises in human development, when it is lost due to neurological disorders and brain injury, and how it is distributed in nonhuman species. This need is amplified by recent and rapid developments in artificial intelligence (AI), neural organoids, and xenobot technology. Although a number of C-tests have been proposed in recent years, most are of limited use, and currently we have no C-tests for many of the populations for which they are most critical. Here, we identify challenges facing any attempt to develop C-tests, propose a multidimensional classification of such tests, and identify strategies that might be used to validate them., SCOPUS: re.j, info:eu-repo/semantics/published

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Background: Anterior uveitis, inflammation of the anterior chamber and related structures, is a cohort of diseases that can present to almost any general or sub-specialty Ophthalmology practice. Its features classically involve anterior chamber cell and flare. Below the surface of these two signs exist a panoply of diagnoses. Body: The purpose of this review is to provide a general framework for diagnoses of anterior uveitis that are often missed as well as non-uveitic pathologies that often mimic anterior uveitis. Diagnostic deviation in either direction can have vision-threatening and rarely life-threatening consequences for patients. Using a comprehensive literature review we have collected a broad spectrum of etiologies of anterior uveitis that are easily missed and non-uveitic pathologies that can masquerade as anterior uveitis. Conclusions: We present a focused review on specific misdiagnosed anterior uveitis pathologies and some of the conditions that can masquerade as anterior uveitis and scleritis., SCOPUS: re.j, info:eu-repo/semantics/published

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Face pareidolia is the illusory perception of a face in ambiguous objects or patterns [1], as reflected by face-selective electroencephalographic (EEG) activity in both adults [2] and infants [3]. However, the perceptual interpretation of these ambiguous stimuli depends on the context in which they are presented [4,5]. In particular, we recently found that, in adults [5], ambiguous face-like stimuli are interpreted as faces in a non-face context and as non-face objects in a face context. Accordingly, here, we aim to explore how visual context shapes the perception of ambiguous stimuli early in life. We measured scalp EEG activity in 4-to-6 months-old infants using a frequency-tagging approach which is particularly suited to test infants because it allows for short and efficient recordings, has an excellent signal-to-noise ratio and is immune to most artifacts [6,7]. Infants were exposed to 20-second sequences of natural images presented at a rate of 6 images per second (6 Hz), with ambiguous stimuli inserted every 5th image (at 1.2 Hz), and face or house images inserted every 4th image (at 1.5 Hz), defining a visual face or non-face context, respectively. Preliminary data (N=10 infants) reveal that the brain response to ambiguous stimuli is weaker in infants than in adults. Contrary to the adult responses, the infant response is also more face-like in the face context (with a typical temporo-parietal location of the response [3]) and shifts to a more occipital response in the non-face context. While these preliminary results still need to be consolidated, they suggest that the influence of visual context on the categorization of ambiguous stimuli changes throughout development, likely due to the effectiveness of perception at a given developmental stage. [1] Wardle et al. 2020, Nature communications [2] Rekow et al. 2022, Cognition [3] Rekow et al. 2021, PNAS [4] Rekow et al. 2022, NeuroImage [5] Bourgaux et al. in prep. [6] Kabdebon et al. 2022, NeuroImage [7] de H, info:eu-repo/semantics/published

Face pareidolia is the illusory perception of a face in ambiguous objects or patterns [1], as reflected by face-selective electroencephalographic (EEG) activity in both adults [2] and infants [3]. However, the perceptual interpretation of these ambiguous stimuli depends on the context in which they are presented [4,5]. In particular, we recently found that, in adults [5], ambiguous face-like stimuli are interpreted as faces in a non-face context and as non-face objects in a face context. Accordingly, here, we aim to explore how visual context shapes the perception of ambiguous stimuli early in life. We measured scalp EEG activity in 4-to-6 months-old infants using a frequency-tagging approach which is particularly suited to test infants because it allows for short and efficient recordings, has an excellent signal-to-noise ratio and is immune to most artifacts [6,7]. Infants were exposed to 20-second sequences of natural images presented at a rate of 6 images per second (6 Hz), with ambiguous stimuli inserted every 5th image (at 1.2 Hz), and face or house images inserted every 4th image (at 1.5 Hz), defining a visual face or non-face context, respectively. Preliminary data (N=10 infants) reveal that the brain response to ambiguous stimuli is weaker in infants than in adults. Contrary to the adult responses, the infant response is also more face-like in the face context (with a typical temporo-parietal location of the response [3]) and shifts to a more occipital response in the non-face context. While these preliminary results still need to be consolidated, they suggest that the influence of visual context on the categorization of ambiguous stimuli changes throughout development, likely due to the effectiveness of perception at a given developmental stage. [1] Wardle et al. 2020, Nature communications [2] Rekow et al. 2022, Cognition [3] Rekow et al. 2021, PNAS [4] Rekow et al. 2022, NeuroImage [5] Bourgaux et al. in prep. [6] Kabdebon et al. 2022, NeuroImage [7] de H, info:eu-repo/semantics/nonPublished

Background Cognitive difficulties are a frequent complaint in long COVID and persist for more than a year post- infection. There is a lack of evidence-based data on effective intervention strategies. Non-pharmacological intervention programs that are used with other neurological populations have not yet been the subject of controlled trials. COVCOG is a multicentric, randomized trial comparing cognitive intervention and a cognitive-behavioural counselling. Methods/design Patients with long covid are selected and recruited at least three months post-infection. Patients are randomised in a 1:1 ratio into the cognitive (neuropsychological psychoeducation) and affective (emotion management with cognitive-behavioural counselling) intervention arms. The inclusion of 130 patients is planned. The cognitive intervention includes psycho-educational modules on fatigue and sleep, attention and working memory, executive functions and long-term memory. The affective intervention includes modules on emotion recognition and communication, uncertainty management and behavioral activation. The main objective is to reduce cognitive complaints 2 months after the intervention. A Follow-up is also planned at 8 months. Discussion Given the long-term effects of Covid on cognition and the negative effects of cognitive impairment on quality of life and social participation, it is important to determine whether low-dose, non-pharmacological interventions can be effective. The trial will determine which of the usual types of intervention is the most effective. Trial registration Clinicaltrials.gov Number: NCT05167266 (21/12/ 2021)., info:eu-repo/semantics/published

Visual statistical learning refers to the ability to detect and extract regularities from the environment. It allows preverbal infants to organise visual stimulation in a coherent representation. Thus far, statistical learning has been primarily investigated with post-exposure behavioural tasks that can only reveal the outcome of learning. Notably, behavioural tasks may lead to ambiguous interpretations since there is no clear consensus about the directionality of the expected learning outcome in infancy (i.e. novelty vs. familiarity effect). Electrophysiological measures such as steady-state visual evoked potentials (SSVEPs) can be acquired while learning occurs and can shed light onto the temporal course of learning. To date, similar investigations have been limited to the auditory domain (Choi et al. 2020). In this study, we propose an EEG frequency tagging approach to study infants’ SSVEPs in response to visual regularities. Participants were 4- to 6-month-old infants born at term. They were presented with continuous streams of 8 colourful shapes appearing in the centre of the screen at a frequency of 6 Hz. Infants were randomly assigned to one of three conditions: 1) the standard doublet condition, in which shapes were organised in doublets, 2) the control doublet condition, in which only the first element of the pair followed a rule, and 3) the single condition, in which individual shapes were randomly presented. We compared SSVEPs at the frequency of visual stimulation (6 Hz and its higher harmonics) and at the doublet frequency (3 Hz and its higher harmonics) across conditions. If the stream of shapes included visual regularities, we hypothesised not only a strong steady-state response at the base frequency of 6 Hz but also a progressive response at 3 Hz. Results revealed neural entrainment at the base frequency of visual stimulation (6 Hz and its harmonics) that did not differ across experimental conditions. This confirms that infants were similarly attendi, info:eu-repo/semantics/published

Introduction: Visual statistical learning allows preverbal infants to organise visual stimulation in a coherent representation. Thus far, early visual statistical learning skills have been measured with post-exposure behavioural tasks that focus on the outcome of learning. These tasks may lead to ambiguous interpretations since there is no clear consensus about the directionality of the expected learning outcome in infancy (i.e. novelty or familiarity effect). Electrophysiological measures can be acquired while learning occurs and can shed light onto the temporal course of learning.Methods: In this exploratory study, we propose an EEG frequency-tagging approach to study 4- to 6-month-old infants’ and adults’ neural entrainment in response to visual regularities. All participants were presented with 20-second sequences including a continuous stream of 8 colourful shapes presented at 6 Hz. Participants were randomly assigned to one of three conditions: a) the standard doublet condition, in which shapes were organised in doublets, b) the control doublet condition, in which only the first element of the pair followed a rule, and c) the single condition, in which individual shapes were randomly presented.Results: Preliminary results reveal that both infants and adults showed neural entrainment at the base frequency of visual stimulation (6 Hz and its harmonics) that did not differ across experimental conditions. This confirms that participants were paying attention to the visual stream of stimuli in all conditions. On the other side, activity at the doublet presentation frequency (3 Hz and its harmonics) varied across conditions. Infants assigned to the doublet conditions showed greater responses at the doublet harmonics, especially at 9 Hz, compared to the single condition. This was similar for adults, although entrainment mechanisms were evident for more harmonics than infants.Conclusion: Overall, these preliminary results suggest that visual regularities in a stream o, info:eu-repo/semantics/published

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Visual statistical learning refers to the ability to detect and extract regularities from the environment. Thus far, infancy research has mostly investigated this ability with post-exposure behavioural tasks which only reveal the outcome of learning. These tasks may also lead to ambiguous interpretations since there is no clear consensus about the directionality of the learning outcome. Steady-state visual evoked potentials (SSVEPs) can be acquired while learning occurs and can shed light onto the temporal course of learning. At present, SSVEPs investigations of the ongoing learning processes have been limited to the auditory domain (Choi et al. 2020). Here we use SSVEPs to investigate infants’ neural entrainment in response to visual regularities. Four- to six-month-old infants were presented with 20 s continuous streams of shapes at 6 Hz. They were randomly assigned to one of three conditions: standard doublet, control doublet, and random. We compared SSVEPs at the frequency of visual stimulation (6 Hz and harmonics) and at the doublet frequency (3 Hz and harmonics) across conditions. If the condition included visual regularities, we hypothesised a progressive response at 3 Hz. Results revealed neural entrainment at the base frequency that did not differ across conditions. On the other side, activity at the doublet frequency varied across conditions. Infants assigned to the standard doublet condition showed significantly greater responses at the doublet frequency compared to the random condition. Overall, these results suggest that the infant brain can detect visual regularities in a stream of shapes from very early on., info:eu-repo/semantics/published

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