Christian O'Reilly

Christian O'Reilly
University of South Carolina | USC · Department of Computer Science & Engineering

B.Ing., M.Sc., Ph.D.

About

110
Publications
33,138
Reads
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Introduction
Christian O’Reilly received his B.Ing (elec eng; 2007), his M.Sc.A. (biomed eng; 2011), and his Ph.D. (biomed eng; 2012) from Polytechnique Montreal. He was a postdoc fellow at the CARSM (2012-2014) and then a NSERC postdoc fellow at McGill's Brain Imaging Center (2014-2015) where he worked on EEG sleep transients. He also worked at the EPFL (2015-2018) on modeling of the thalamocortical loop and at McGIll on brain connectivity (2020-2021). Since 2021, he is Assistant Professor at UofSC.
Additional affiliations
August 2021 - present
University of South Carolina
Position
  • Professor (Assistant)
January 2020 - August 2021
McGill University
Position
  • Research Associate
October 2015 - November 2018
Swiss Federal Institute of Technology in Lausanne
Position
  • PostDoc Position
Education
May 2012
Université de Montréal
Field of study
  • Sciences biomédicales
January 2008 - June 2012
Polytechnique Montréal
Field of study
  • biomedical engineering
January 2008 - May 2011
Polytechnique Montréal
Field of study
  • biomedical engineering

Publications

Publications (110)
Article
Full-text available
As our understanding of the thalamocortical system deepens, the questions we face become more complex. Their investigation requires the adoption of novel experimental approaches complemented with increasingly sophisticated computational modeling. In this review, we take stock of current data and knowledge about the circuitry of the somatosensory th...
Article
Full-text available
Electroencephalographic (EEG) source reconstruction is a powerful approach that allows anatomical localization of electrophysiological brain activity. Algorithms used to estimate cortical sources require an anatomical model of the head and the brain, generally reconstructed using magnetic resonance imaging (MRI). When such scans are unavailable, a...
Article
Whether neuronal populations exhibit zero‐lag (in‐phase or in‐antiphase) functional connectivity is a fundamental question when conceptualizing communication between cell assemblies. It also has profound implications on how we assess such interactions. Given that the brain is a delayed network due to the finite conduction velocity of the electrical...
Article
Full-text available
Background Although it is well recognized that autism is associated with altered patterns of over- and under-connectivity, specifics are still a matter of debate. Little has been done so far to synthesize available literature using whole-brain electroencephalography (EEG) and magnetoencephalography (MEG) recordings. Objectives 1) To systematically...
Article
Full-text available
Manual processing of sleep recordings is extremely time-consuming. Efforts to automate this process have shown promising results, but automatic systems are generally evaluated on private databases, not allowing accurate cross-validation with other systems. In lacking a common benchmark, the relative performances of different systems are not compare...
Article
Full-text available
Nonverbal connection is an important aspect of everyday communication. For romantic partners, nonverbal connection is essential for establishing and maintaining feelings of closeness. EEG hyperscanning offers a unique opportunity to examine the link between nonverbal connection and neural synchrony among romantic partners. This current study used a...
Preprint
Nonverbal connection is an important aspect of everyday communication. For romantic partners, nonverbal connection is essential for establishing and maintaining feelings of closeness. EEG hyperscanning offers a unique opportunity to examine the link between nonverbal connection and neural synchrony among romantic partners that has yet to be clearly...
Preprint
Full-text available
Several decades of research have investigated neural connections between stroke-induced brain damage and language difficulties. Typically, lesion-symptom mapping (LSM) studies addressing this connection have relied on mass univariate statistics, which do not account for intricate, multidimensional relationships between variables. Machine learning (...
Preprint
Full-text available
Naturalistic paradigms can assure ecological validity and yield novel insights in psychology and neuroscience. However, using behavioral experiments to obtain the human ratings necessary to analyze data collected with these paradigms is usually costly and time-consuming. Large language models like GPT have great potential for predicting human-like...
Preprint
Full-text available
The study of effective connectivity (EC) is essential in understanding how the brain integrates and responds to various sensory inputs. Model-driven estimation of EC is a powerful approach that requires estimating global and local parameters of a generative model of neural activity. Insights gathered through this process can be used in various appl...
Preprint
Full-text available
Electroencephalography (EEG) is a neuroimaging technique used to record the electrical activity generated by the brain. EEG recordings are often contaminated by various artifacts, notably those caused by eye movements and blinks (EOG artifacts). Independent component analysis (ICA) is commonly applied to isolate EOG artifacts and subtract the corre...
Preprint
Full-text available
Background Independent Component Analysis (ICA) is a well-established approach to clean EEG and remove the impact of signals of non-neural origin, such as those from muscular activity and eye movements. However, evidence suggests that ICA removes artifacts less effectively in infants than in adults. This study systematically compares ICA and Artifa...
Preprint
Full-text available
Autism Spectrum Disorder (ASD) is a range of neurodevelopmental conditions characterized by impaired social interaction, learning, and restricted or repetitive behaviors. The underlying causes of ASD are still debated, but researchers have found many physiological traits to help understand the etiology of ASD.Some of the features that characterize...
Preprint
Full-text available
EEG recordings are typically long and contain large amounts of data, making manual cleaning a time-consuming and error-prone task. Automated pre-processing pipelines can facilitate the efficient and objective extraction of artifacts, enabling standardized and reproducible analyses. However, automated pre-processing pipelines typically remove data c...
Preprint
Full-text available
Infants born preterm are at a significantly higher likelihood of having autism spectrum disorder (ASD). Preterm birth and ASD are both associated with neurological differences, notably autonomic nervous system (ANS) dysfunction, pointing to neonatal ANS dysfunction as a potential pathway to ASD, particularly in VPT infants. In this study, a subset...
Chapter
This invited special session of IGS 2023 presents the works carried out at Laboratoire Scribens and some of its collaborating laboratories. It summarises the 17 talks presented in the colloquium #611 entitled « La lognormalité: une fenêtre ouverte sur le contrôle neuromoteur» (Lognormality: a window opened on neuromotor control), at the 2023 confer...
Article
Full-text available
Background Many studies have reported that autism spectrum disorder (ASD) is associated with atypical structural and functional connectivity. However, we know relatively little about the development of these differences in infancy. Methods We used a high-density electroencephalogram (EEG) dataset pooled from two independent infant sibling cohorts,...
Article
Patients with neurocognitive disorders often battle sleep disturbances. Kynurenic acid is a tryptophan metabolite of the kynurenine pathway implicated in the pathology of these illnesses. Modest increases in kynurenic acid, an antagonist at glutamatergic and cholinergic receptors, result in cognitive impairments and sleep dysfunction. We explored t...
Article
Full-text available
In recent years, there has been a rise in the prevalence of autism spectrum disorder (ASD). The diagnosis of ASD requires behavioral observation and standardized testing completed by highly trained experts. Early intervention for ASD can begin as early as 1–2 years of age, but ASD diagnoses are not typically made until ages 2–5 years, thus delaying...
Article
Full-text available
Modeling is essential to better understand the generative mechanisms responsible for experimental observations gathered from complex systems. In this work, we are using such an approach to analyze the electrocardiogram (ECG). We present a systematic framework to decompose ECG signals into sums of overlapping lognormal components. We use reinforceme...
Preprint
Full-text available
In recent years, there has been a rise in the prevalence of autism spectrum disorder (ASD). The diagnosis of ASD requires behavioral observation and standardized testing completed by highly trained experts. Early intervention for ASD can begin as early as 1-2 years of age, but ASD diagnoses are not typically made until ages 2-5 years, thus delaying...
Preprint
Full-text available
Background: Many studies have reported that autism spectrum disorder (ASD) is associated with atypical structural and functional connectivity. However, relatively little is known about the development of these differences in infancy and on how trajectories may vary between sexes. Methods: We used the International Infant EEG Platform (EEG-IP), a h...
Preprint
Full-text available
Modeling is essential to understand better the generative mechanisms responsible for experimental observations gathered from complex systems. In this work, we are using such an approach to analyze the electrocardiogram (ECG). We present a systematic framework to decompose ECG signals into sums of overlapping lognormal components. We used reinforcem...
Article
Full-text available
Understanding the neural processes underpinning individual differences in early language development is of increasing interest, as it is known to vary in typical development and to be quite heterogeneous in neurodevelopmental conditions. However, few studies to date have tested whether early brain measures are indicative of the developmental trajec...
Article
Full-text available
Thalamoreticular circuitry plays a key role in arousal, attention, cognition, and sleep spindles, and is linked to several brain disorders. A detailed computational model of mouse somatosensory thalamus and thalamic reticular nucleus has been developed to capture the properties of over 14,000 neurons connected by 6 million synapses. The model recre...
Preprint
Full-text available
Thalamoreticular circuitry is central to sensory processing, attention, and sleep, and is implicated in numerous brain disorders, but the cellular and synaptic mechanisms remain intractable. Therefore, we developed the first detailed microcircuit model of mouse thalamus and thalamic reticular nucleus that captures morphological and biophysical prop...
Article
There is substantial evidence of age-related declines in anatomical connectivity during adulthood, with associated alterations in functional connectivity. But the relation of those functional alterations to the structural reductions is unclear. The complexities of both the structural and the functional connectomes make it difficult to determine suc...
Preprint
Full-text available
Functional connectivity computed from electroencephalograms (EEG) can be used to better understand how the brain works. Unfortunately, estimating such connectivity is fraught with many pitfalls and can be confounded with artifacts due to volume conduction, common sources, reference scheme, etc. Devising a method to compute surrogate EEG that would...
Preprint
Full-text available
Zero-lag synchrony is generally discarded from functional connectivity studies to eliminate the confounding effect of volume conduction. Demonstrating genuine and significant unlagged synchronization between distant brain regions would indicate that most electroencephalography (EEG) connectivity studies neglect an important mechanism for neuronal c...
Article
Objectives: Sleepwalkers have consistently shown N3 sleep discontinuity, especially after sleep deprivation. In healthy subjects, sleep spindles activity has been positively correlated to sleep stability. We aimed to compare spindles density during N3 sleep between sleepwalkers and healthy controls. Methods: Two cohorts of 10 and 21 adult sleepw...
Preprint
Full-text available
As our understanding of the thalamocortical system deepens, the questions we face become more complex. Their investigation requires the adoption of novel experimental approaches complemented with increasingly sophisticated computational modeling. In this review, we take stock of current data and knowledge about the circuitry of the somatosensory th...
Preprint
Full-text available
Electroencephalographic (EEG) source reconstruction is a powerful approach that helps to unmix scalp signals, mitigates volume conduction issues, and allows anatomical localization of brain activity. Algorithms used to estimate cortical sources require an anatomical model of the head and the brain, generally reconstructed using magnetic resonance i...
Preprint
Full-text available
Whether neuronal populations exhibit zero-lag (in-phase or in-antiphase) functional connectivity is a fundamental question when conceptualizing communication between cell assemblies. It also has profound implications on how we assess such interactions. Given that the brain is a delayed network due to the finite conduction velocity of the electrical...
Article
Full-text available
The curation of neuroscience entities is crucial to ongoing efforts in neuroinformatics and computational neuroscience, such as those being deployed in the context of continuing large-scale brain modelling projects. However, manually sifting through thousands of articles for new information about modelled entities is a painstaking and low-reward ta...
Article
Full-text available
Somatosensory thalamocortical (TC) neurons from the ventrobasal (VB) thalamus are central components in the flow of sensory information between the periphery and the cerebral cortex, and participate in the dynamic regulation of thalamocortical states including wakefulness and sleep. This property is reflected at the cellular level by the ability to...
Article
Full-text available
We present Visbrain, a Python open-source package that offers a comprehensive visualization suite for neuroimaging and electrophysiological brain data. Visbrain consists of two levels of abstraction: 1) objects which represent highly configurable neuro-oriented visual primitives (3D brain, sources connectivity, etc.) and 2) graphical user interface...
Preprint
Full-text available
Somatosensory thalamocortical (TC) neurons from the ventrobasal (VB) thalamus are central components in the flow of sensory information between the periphery and the cerebral cortex, and participate in the dynamic regulation of thalamocortical states including wakefulness and sleep. This property is reflected at the cellular level by the ability to...
Article
Full-text available
Studies have shown that both nicotine and sleep spindles are associated with enhanced memorisation. Further, a few recent studies have shown how cholinergic input through nicotinic and muscarinic receptors can trigger or modulate sleep processes in general, and sleep spindles in particular. To better understand the interaction between nicotine and...
Article
Full-text available
We introduce Sleep, a new Python open-source graphical user interface (GUI) dedicated to visualization, scoring and analyses of sleep data. Among its most prominent features are: (1) Dynamic display of polysomnographic data, spectrogram, hypnogram and topographic maps with several customizable parameters, (2) Implementation of several automatic det...
Article
Full-text available
We introduce Sleep, a new Python open-source graphical user interface (GUI) dedicated to visualization, scoring and analyses of sleep data. Among its most prominent features are: 1) Dynamic display of polysomnographic data, spectrogram, hypnogram and topographic maps with several customizable parameters, 2) Implementation of several automatic detec...
Conference Paper
Full-text available
The thalamo-cortical system constitutes an important part of the mammalian brain and regulates several functions, such as transition between sleep and wakefulness and gating of sensory information. Understanding this kind of complex neural system can be greatly facilitated by data-driven computer simulations. With this aim in mind, the Blue Brain P...
Article
Full-text available
Large models of complex neuronal circuits require specifying numerous parameters, with values that often need to be extracted from the literature, a tedious and error-prone process. To help establishing shareable curated corpora of annotations, we have developed a literature curation framework comprising an annotation format, a Python API (NeuroAnn...
Article
Full-text available
Sleep spindles and K-complexes are among the most prominent micro-events observed in electroencephalographic (EEG) recordings during sleep. These EEG microstructures are thought to be hallmarks of sleep-related cognitive processes. Although tedious and time-consuming, their identification and quantification is important for sleep studies in both he...
Article
Full-text available
Face recognition is a highly specialized capability that has implicit and explicit memory components. Studies show that learning tasks with facial components are dependent on rapid eye movement and non-rapid eye movement sleep features, including rapid eye movement sleep density and fast sleep spindles. This study aimed to investigate the relations...
Article
Full-text available
Research on sleep spindles and their correlates has progressed steadily over the last decade. The subject has evolved from a simple topic of investigation to an emerging research field, as indicated this year by the first international conference on sleep spindles in Budapest, Hungary, as well as the launching of a scientific journal (i.e., Sleep S...
Article
Full-text available
We introduce Sleep, a new Python open-source graphical user interface (GUI) dedicated to visualization, scoring and analyses of sleep data. Among its most prominent features are: (1) Dynamic display of polysomnographic data, spectrogram, hypnogram and topographic maps with several customizable parameters, (2) Implementation of several automatic det...
Poster
Full-text available
Building large-scale realistic models of neuronal circuits such as those being designed in the context of the Blue Brain Project requires setting values to a large number of parameters. Previously reported values must therefore be systematically extracted from the literature, in some cases to be directly included in the model (e.g., when no experim...
Conference Paper
Les fuseaux de sommeil sont des bouffées d’activité cérébrale entre 8 et 12 Hz potentiellement impliquées dans la consolidation de la mémoire visuo-motrice (Tamaki et al., 2008). Dans une étude (Dumel et al. 2015), une amélioration à la tâche visuo-motrice Mirror Tracing Task (MTT) corrélait avec le sommeil de stade N2 chez des petits rêveurs (r=.5...
Article
Full-text available
Sleep spindle properties index cognitive faculties such as memory consolidation and diseases such as major depression. For this reason, scoring sleep spindle properties in polysomnographic recordings has become an important activity in both research and clinical settings. The tediousness of this manual task has motivated efforts for its automation....
Article
Full-text available
To investigate differences in sleep spindle properties and scalp topography between patients with rapid eye movement sleep behaviour disorder (RBD) and healthy controls, whole-night polysomnograms of 35 patients diagnosed with RBD and 35 healthy control subjects matched for age and sex were compared. Recordings included a 19-lead 10-20 electroencep...
Article
Full-text available
We present a complete framework for time-frequency parametrization of EEG transients, based upon matching pursuit (MP) decomposition, applied to the detection of sleep spindles. Ranges of spindles duration (>0.5 s) and frequency (11–16 Hz) are taken directly from their standard definitions. Minimal amplitude is computed from the distribution of the...
Article
Full-text available
This paper investigates the advantage of using the kinematic theory of rapid human movements as a complementary approach to those based on classical dynamical features to characterize and analyze kindergarten children's ability to engage in graphomotor activities as a preparation for handwriting learning. This study analyzes nine different movement...
Conference Paper
Les fuseaux de sommeil se produisent au cours du sommeil non-REM et plus particulièrement en stade N2. De nombreuses études proposent qu’ils sont impliqués dans différents processus mnésiques (O’Reilly & Nielsen, 2014) telle que la mémoire visuo-motrice (Tamaki et al., 2008). L’étude polysomnographique de Dumel et al. (en révision, Journal of Sle...
Article
Full-text available
EEG sleep spindles are short (0.5–2.0 s) bursts of activity in the 11–16 Hz band occurring during non-rapid eye movement (NREM) sleep. This sporadic activity is thought to play a role in memory consolidation, brain plasticity, and protection of sleep integrity. Many automatic detectors have been proposed to assist or replace experts for sleep spind...