Title Promoter Affiliations Abstract "Cognitive workload monitoring during virtual reality gameplay by combining performance and task difficulty with EEG with ECG recordings" "Marc Van Hulle" "Laboratory for Neuro- and Psychophysiology" "Current evidence suggests that short training sessions can improve cognitive performance of elder individuals and postpone age-related cognitive decline development. But the expected outcome could be compromised when these sessions increase the subject's cognitive workload (CW) -the interaction between mental demands of the task and the subject's ability to perform them. Several attempts have been made to relate CW to task difficulty, leaving out the subject-dependent factor. In order to gauge the latter, we propose to record EEGs, and to extract the EEG components that reflect attention-related and working memory processes, and electrocardiograms (ECGs) as the latter are known to be sensitive to CW, not only in terms of engagement, but also in terms of fatigue, drowsiness and boredom. We will consider a virtual reality (VR) game task as such settings have been shown to yield beneficial training effects. Our goal is to develop a statistical model that will combine VR game performance, task difficulty, and EEG and ECG recordings with the aim to predict and track, in real-time, an individual's CW during task performance and to adjust task complexity so as to avoid boredom and fatigue. As a proof of concept, we will test our approach on both healthy young and older individuals as CW differences are expected between these two age groups. When successful, it would signify a breakthrough in the applicability of EEG/ECG-based CW monitoring in cognitive training applications." "Probabilistic decoding of EEG potentials evoked by word associations." "Marc Van Hulle" "Laboratory for Neuro- and Psychophysiology, Methods, Individual and Cultural Differences, Affect and Social Behavior" "The N400 potential has been instrumental to our understanding of how language is encoded in the brain. Recorded through electroencephalography (EEG), it is most strongly evoked in response to the sequential presentation of two anomalous words, but it is absent for strongly associated ones. The spectrum of association strengths of word pairs in relation to the evoked N400 effect has not yet been modeled but, when successful, it could provide evidence for the structure of semantic memory. The aim of this project is to develop for the first time an algorithm that automatically detects the N400 and that generates an estimate for the association strength between the words that has generated it. The theory behind this algorithm also forms the basis for a second algorithm that will arrange a given set of N400 word pair responses into a graphical model called semantic network. We will use carefully composed sets of word pairs, with increasing association strength, to train and assess our detection algorithm, and to compare the semantic network estimated by the second algorithm with the available one derived from behavioral measurements (e.g. rating scales). The challenge of the second algorithm is to reconcile association strength estimation based on the N400 with semantic network inference issues." "Objectively assessing dyadic biobehavioural synchrony via dual eye-tracking, dual EEG and ANS stress physiology recording, and detailed video monitoring" "Bart Boets" "Quantitative Psychology and Individual Differences, Research Group for Neurorehabilitation (eNRGy), Contextual Psychiatry, Department of Human Genetics, Clinical Psychiatry, Interfaculty Institute for Family and Sexuality Studies, Parenting and Special Education, Locomotor and Neurological Disorders, Woman and Child, Mind-body Research, Neuropsychiatry, Developmental Psychiatry" "Humans are social beings by excellence. Due to the social and bodily embeddedness during early development, biological and behavioural processes become entrained and coordinated with the interacting partner. This biobehavioural synchrony is evident across behaviour, stress physiology, hormones and brain processing, and across multiple human attachment constellations (e.g., parent-infant pairs, romantic lovers, strangers). Paradoxically, however, conventional socio-affective neuroscience approaches typically examine individual humans in isolation, in very artificial non-ecological settings. Yet, recent technological advances allow us to study dyadic interactions by recording from both partners at the same time. With the present proposal, we apply for equipment that will allow us to measure eye gaze, neural processing, stress physiology, and behaviour simultaneously in two individuals while they are engaged in real-life interactions. This cutting-edge approach will introduce a paradigm shift in socio-affective research and will allow us to study how these multimodal temporal signals relate to each other (within-subject interdependency), how they relate to the multimodal signals of the interacting partner (inter-subject interdependency), and how this mutual dyadic biobehavioural attunement may be disturbed in atypical development and psychiatric conditions." "The mystery of instruction following: Computational modeling and EEG studies" "Tom Verguts" "Department of Experimental psychology" "People can implement without effort instructions that are typically completely novel (e.g., “Please give me the blue cup”). How they do so, is still a mystery. In the current project this will be addressed from a conceptual framework that has not been used for this purpose, called binding by synchrony. Binding by synchrony has proven very fruitful in the perception and attention literatures. Binding by synchrony entails that elements (e.g., “blue” and “cup”) are bound together in the brain by letting the neurons corresponding to the respective elements fire at the same time (“in phase”). This principle is eminently suited to implement completely novel information, such as instructions, because it allows binding and unbinding of elements extremely rapidly. We will construct a computational model of instruction following that implements the principle. We will also consider how such a model can be trained by reinforcement learning. In a next step, we will perform EEG studies both to test the general principle that instructions are implemented using binding by synchrony, and also more specific model predictions." "Advanced EEG technology in childhood epilepsy: A multimodal wearable approach for long-term seizure detection and sleep monitoring" "Katrien Jansen" "Locomotor and Neurological Disorders, Laboratory for Epilepsy Research" "A lot of effort has already been put into the development of smaller, wearable and more user-friendly devices to monitor seizures in patients with epilepsy. The investigators hypothesize that a wearable EEG ( in combination with additional non-EEG biosignals (motion, ECG, EMG, respiration, temperature,...) derived from Byteflies Sensor Dot and new medical patches (Plug 'n Patch system), will be able to objectively detect epileptic seizures and monitor sleep in the hospital and home environment for specific types of childhood epilepsy. The accuracy of seizure detection and sleep monitoring by the wearable miniature EEG device in combination with other (autonomic) biosignals (full PnP system) will be compared with the golden standard video-EEG and seizure and sleep diaries filled-out by the participants. The objective of the study will be the following: 1.Multimodal seizure detection Evaluation of data quality and seizure annotation accuracy. Comparison of data derived from the multimodal wearable device (Sensor dot in combination with Plug and Patch system) versus video EEG and seizure diary in childhood epilepsy syndromes with ◦Tonic seizures ◦Atonic seizures ◦Myoclonic seizures During wakefulness and during sleep 2.Sleep monitoring Assessment of sleep data quality, latency, sleep fragmentation and time spent in different sleep stages in different childhood epilepsy syndromes. Investigation of the influence of occuring seizures on sleep architecture. Comparison of data wearable device (Byteflies Sensor Dot in combination with Plug and Patch system) versus video-EEG and sleep diary in childhood epilepsy syndromes." "Distributed wireless EEG sensor patches for auditory attention decoding in hearing technology" "Alexander Bertrand" "Dynamical Systems, Signal Processing and Data Analytics (STADIUS)" "Over 400 million people worldwide suffer from disabling hearing loss. While the majority can be helped with a hearing aid, users still experience major difficulties in situations where multiple people talk simultaneously, leading to social isolation. Although algorithms exist to extract a single speaker from such a speech mixture, the current bottleneck is that a hearing aid does not know which of these speakers the user aims to attend.Recent research has shown that this auditory attention can be decoded from the brain via electroencephalography (EEG). However, a practical realization in hearing aids is hindered by current EEG form factors: headsets are too bulky, while miniaturized sensors lack a wide scalp coverage. Furthermore, conventional EEG requires applying a gel on the skin, which dries out over time.To address these issues, we propose a novel modular approach using 4 wireless EEG sensor patches strategically positioned on hairless scalp locations. This offers several advantages, such as (1) increased scalp coverage for improved decoding accuracy while maintaining comfort and discreteness due to a far-driven miniaturization and absence of wires; (2) the use of dry adhesive patches with skin-conforming microneedle electrodes for high-quality EEG recording without gel; (3) efficient algorithms that process signals and exchange compressed data wirelessly over short distances with minimal energy usage, thereby maximizing battery life.In this project we will develop an operational prototype of this system drawing from our recent ERC-originated innovations, and validate it on hearing-impaired subjects." "EEG signatures of cognitive impairment during stages of cognitive decline" "Marc Van Hulle" "Laboratory for Neuro- and Psychophysiology" "Cognitive decline is one of the main traits of several neurodegenerative disorders and can severely affect the life quality of both patients and caregivers. There are around 50 million dementia patients worldwide, a number that is expected to escalate rapidly in the future. The early and objective assessment of cognitive deficits, irrespective of their origin, not only serves diagnostic purposes, but is also crucial to assess the speed of progression and to implement patient management measures timely, including financial ones. Although quantitative electroencephalography (EEG) may not yet be included in the clinical work-up of patients with Alzheimer’s disease (AD), the technique has provided evidence to successfully distinguish between healthy participants and patients with dementia. Furthermore, EEG is a non-invasive and non-expensive technique compared to the analysis of cerebral spinal fluid (CSF), FDG-PET and MRI volumetry, which are commonly used to assess AD pathology. Since it has been shown that pathological changes in AD precede clinical manifestation by several years, we aim to differentiate between multiple stages of cognitive decline using the EEG methodology. We will include patients with subjective and mild cognitive impairment as well as AD patients. Finally, we aim to correlate the EEG features with established biomarkers of AD pathology (e.g., CSF, FDG-PET, MRI). When successful, this would further validate EEG for use in clinical settings and possibly even provide a better understanding of the disease itself." "EEG Connectivity-based Biomarkers of Stroke Recovery" "Dante Mantini" "Movement Control & Neuroplasticity Research Group" "The PhD project aims at characterizing potential EEG-based functional connectivity biomarkers of stroke recovery, particularly regarding language abilities.The goal of the first Work Package (WP1) will be to identify the resting-state functional connectivity indices that are better suited to differentiate left-hemisphere stroke patients, right-hemisphere stroke patients, and healthy controls. WP2 will test for the prognostic significance of the resting-state functional connectivity indices selected from WP1. WP3 will aim to explore whether EEG recordings other than resting state (e.g. passive listening of a piece of music and/or excerpt from a novel) are better suited to discriminate left-hemisphere stroke patients, right-hemisphere stroke patients, and healthy controls." "EEG alpha-theta (cross-frequency) dynamics during arithmetic performance, mind wandering and meditative states" "Kaat Alaerts" "Research Group for Neurorehabilitation (eNRGy), Movement Control & Neuroplasticity Research Group" "Neural oscillations have been shown to be functionally relevant for human behaviour. In this way, brain rhythms oscillating at different frequencies have been associated to different cognitive functions. Consequently, the interplay between brain rhythms in different frequency ranges (i.e. cross-frequency coupling) is thought to be essential for cognition to emerge. This thesis focuses on cross-frequency dynamics between EEG alpha (8-14 Hz) and theta (4-8 Hz) rhythms during different cognitive states. Specifically, it investigates the functional relevance of alpha:theta cross-frequency numerical ratios during arithmetic performance, mind wandering and meditative states. This approach to alpha-theta cross-frequency dynamics is based on a recent theory positing that the formation of different cross-frequency numerical ratios between the peak frequencies of two brain rhythms is reflective of their level of interaction. In this way, it is proposed that harmonic cross-frequency arrangements (e.g. 2:1 numerical ratio) would enable cross-frequency coupling. The rationale behind this premise is that only harmonic cross-frequency ratios allow stable and regular excitatory phase meetings between two neural populations (i.e. coincidence of time periods in which spiking is more likely to occur).The working hypothesis in this thesis was that alpha and theta rhythms would arrange more often in harmonic positions during both working memory tasks and mind wandering. This hypothesis was based on previous literature suggesting that alpha (8-14Hz) and theta (4-8 Hz) rhythms reflect different components of working memory that need to be integrated when information has to be stored and manipulated in the brain. This hypothesis was assessed throughout the four studies encompassing this thesis. In the first study (Chapter 2), we assess the incidence of different alpha:theta cross-frequency ratios during an arithmetic task with a strong working memory component, rest and meditation practice. It was shown that alpha and theta rhythms separated in the frequency domain during arithmetic performance (relative to rest and meditation) thereby increasing the incidence of cross-frequency numerical ratios between 2 and 3 (and therefore 2:1 and 3:1 phase synchrony). These changes were accompanied by a decreased occurrence of ratios between 1 and 1.6. Interestingly, the separation between alpha and theta rhythms in the frequency domain (i.e. increased occurrence of ratios around 2 and 3 and decreased occurrence of ratios between 1 and 1.6) were positively associated to arithmetic performance, thereby underlining their functional relevance.  A similar pattern of results was observed in the second study (Chapter 3), in which the same paradigm was adopted but with participants that were highly experienced in meditation practice. In addition to the previously reported changes during arithmetic task (relative to rest and meditation practice), we report that meditation was associated to a decreased incidence of alpha:theta ratios between 2 and 3 and an increased incidence of alpha:theta ratios between 1 and 1.6 when compared to rest and arithmetic. Based on these latter results, it was speculated that these changes in alpha-theta cross-frequency dynamics could be attributed to reduced mind wandering during meditation. To further investigate the influence of meditation training in alpha:theta cross-frequency dynamics, we assessed in a third study (Chapter 4) whether the compliance to a meditation training course was significantly correlated to changes in the incidence of different alpha:theta cross-frequency ratios during meditation. In this way, we show that meditation training (i.e. minutes of attendance plus minutes of practice at home) was associated to an approximation of alpha and theta rhythms in the frequency domain (i.e. a decreased occurrence of alpha:theta cross-frequency ratios around 3 and an increased occurrence of cross-frequency ratios around 1.6). In line with the previous study, we speculated that these inter-individual differences in the incidence of different alpha:theta numerical ratios during mediation were associated to mind wandering. Finally, in the fourth study (Chapter 5) we directly assess whether the occurrence of different alpha:theta cross-frequency ratios were associated to mind wandering in the context of meditation practice. For this purpose, a sample of novice meditators were repeatedly interrupted during a breath focus meditation to report whether they were mind wandering or focusing on their breath. In line with previous findings, our results showed that mind wandering is associated to a separation of alpha and theta rhythms in the frequency domain (i.e. an increased incidence of alpha:theta ratios between 2 and 3 at the expense of the occurrence of alpha:theta ratios between 1 and 1.6).Together, our results consistently show a separation of alpha and theta rhythms in the frequency domain (higher mean alpha:theta numerical ratio) during both arithmetic performance (relative to rest) and mind wandering (in the context of meditation practice). Although these changes in alpha:theta cross-frequency ratios led to greater 2:1 and 3:1 harmonicity and phase synchrony between alpha and theta rhythms, the observed changes in the frequency architecture (as indexed by the incidence of different cross-frequency ratios) do not unequivocally reflect changes in the level of interaction between alpha (8-14Hz) and theta (4-8 Hz) rhythms.  Therefore, we cannot conclude that here studied cognitive states involve different levels of communication between the neural populations that are entrained by neural oscillations in the alpha and theta range. In this way, changes in the incidence of different ratios cross-frequency ratios would remain descriptive and open to interpretation until future studies empirically disentangle whether: i) alpha and theta rhythms encompass two separate neural oscillations with exclusively sinusoidal properties and ii) different cross-frequency ratios reflect different levels of information exchange between neural rhythms. Regardless the interpretation we give to the incidence of different alpha:theta ratios, the here presented studies suggest the existence of a neurocognitive mechanism that supports both working memory task performance and mind wandering.  " "EEG measures and bodily symptoms" "Andreas von Leupoldt" "Health Psychology" "This project is part of our Methusalem research project “ASTHENES”, which aims at unravelling the biobehavioral mechanisms underlying the transition from acute aversive sensations to chronic bodily symptoms (eg, dyspnea and pain). Specifically, the focus of this 4-year PhD project will be the examination of potential neural markers using EEG methodology, which are related to increased perception of bodily sensations."