Pierre Bellec

Pierre Bellec
Université de Montréal | UdeM · Department of Psychology

PhD

About

249
Publications
30,805
Reads
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5,655
Citations
Additional affiliations
August 2019 - October 2019
Université de Montréal
Position
  • Professor (Associate)
April 2006 - March 2010
McGill University
Position
  • PostDoc Position

Publications

Publications (249)
Preprint
Playing video games in a neuroimaging environment is both scientifically promising and technically challenging. Primary among these challenges is the need to use scanner-compatible devices to register player inputs, which limits the type of games that can be comfortably played in a scanner and often reduces the ecological validity of video game tas...
Article
Pleiotropy occurs when a genetic variant influences more than one trait. This is a key property of the genomic architecture of psychiatric disorders and has been observed for rare and common genomic variants. It is reasonable to hypothesize that the microscale genetic overlap (pleiotropy) across psychiatric conditions and cognitive traits may lead...
Article
Background Polygenicity and genetic heterogeneity pose great challenges for studying psychiatric conditions. Genetically-informed approaches have been implemented in neuroimaging studies to address this issue. However, the effects on functional connectivity of rare and common genetic risks for psychiatric disorders are largely unknown. Our objectiv...
Conference Paper
Full-text available
Recent advances in the field of Artificial Intelligence have paved the way for the development of novel brain encoding models. Artificial Neural networks (ANN) can be trained to replicate the properties of brain dynamics in a range of cognitive processes. Videogames provide a promising framework linking brain activity to individual behavior in a na...
Article
Importance: Preventive trials of anti-amyloid agents might preferably recruit persons showing earliest biologically relevant β-amyloid (Aβ) binding on positron emission tomography (PET). Objective: To investigate the timing at which Aβ-PET binding starts showing associations with other markers of Alzheimer disease. Design, setting, and particip...
Article
Importance: National Institute on Aging-Alzheimer's Association (NIA-AA) workgroups have proposed biological research criteria intended to identify individuals with preclinical Alzheimer disease (AD). Objective: To assess the clinical value of these biological criteria to identify older individuals without cognitive impairment who are at near-te...
Article
Decoding cognitive processes from recordings of brain activity has been an active topic in neuroscience research for decades. Traditional decoding studies focused on pattern classification in specific regions of interest and averaging brain activity over many trials. Recently, brain decoding with graph neural networks has been shown to scale at fin...
Article
Full-text available
Previous literature has focused on predicting a diagnostic label from structural brain imaging. Since subtle changes in the brain precede cognitive decline in healthy and pathological aging, our study predicts future decline as a continuous trajectory instead. Here, we tested whether baseline multimodal neuroimaging data improve the prediction of f...
Preprint
Full-text available
NeuroLibre is a preprint server for neuroscience Jupyter Books, blending code, visualization and narrative text into one document. NeuroLibre archives the environment, code and data and also implements a technical review to ensure readers can reproduce the work. NeuroLibre offers an online platform where readers can reproduce or modify each preprin...
Article
Full-text available
Background: Hippocampal atrophy is a well-known biomarker of neurodegeneration, such as that observed in Alzheimer's disease (AD). Although distributions of hippocampal volume trajectories for asymptomatic individuals often reveal substantial heterogeneity, it is unclear whether interpretable trajectory classes can be objectively detected and used...
Preprint
Large-scale data-centric challenges faced by neuroscientists, such as improving reproducibility and data reuse, could be overcome by adopting open science practises. The Canadian Open Neuroscience Platform (CONP) takes a multi-faceted approach to enabling open neuroscience, aiming to make research, data, and tools accessible to everyone, with the u...
Preprint
Full-text available
Brain decoding aims to infer cognitive states from recordings of brain activity. Current literature has mainly focused on isolated brain regions engaged in specific experimental conditions, but ignored the integrative nature of cognitive processes recruiting distributed brain networks. To tackle this issue, we propose a connectome-based graph neura...
Preprint
Full-text available
Brain decoding aims to infer human cognition from recordings of neural activity using modern neuroimaging techniques. Studies so far often concentrated on a limited number of cognitive states and aimed to classifying patterns of brain activity within a local area. This procedure demonstrated a great success on classifying motor and sensory processe...
Article
Full-text available
To move Alzheimer Disease (AD) research forward it is essential to collect data from large cohorts, but also make such data available to the global research community. We describe the creation of an open science dataset from the PREVENT-AD (PResymptomatic EValuation of Experimental or Novel Treatments for AD) cohort, composed of cognitively unimpai...
Preprint
Full-text available
Polygenicity and pleiotropy are key properties of the genomic architecture of psychiatric disorders. An optimistic interpretation of polygenicity is that genomic variants converge on a limited set of mechanisms at some level from genes to behavior. Alternatively, convergence may be minimal or absent. We took advantage of brain connectivity, measure...
Article
Full-text available
Neuroimaging genomic studies of autism spectrum disorder and schizophrenia have mainly adopted a ‘top-down’ approach, starting with the behavioural diagnosis, and moving down to intermediate brain phenotypes and underlying genetic factors. Advances in imaging and genomics have been successfully applied to increasingly large case-control studies. As...
Article
Full-text available
Even though sleep modification is a hallmark of the aging process, age-related changes in functional connectivity using functional Magnetic Resonance Imaging (fMRI) during sleep, remain unknown. Here, we combined electroencephalography and fMRI to examine functional connectivity differences between wakefulness and light sleep stages (N1 and N2 stag...
Preprint
Full-text available
Brainhack is an innovative meeting format that promotes scientific collaboration and education in an open and inclusive environment. Departing from the formats of typical scientific workshops, these events are based on grassroots projects and training, and foster open and reproducible scientific practices. We describe here the multifaceted, lasting...
Article
Full-text available
A key goal in neuroscience is to understand brain mechanisms of cognitive functions. An emerging approach is “brain decoding”, which consists of inferring a set of experimental conditions performed by a participant, using pattern classification of brain activity. Few works so far have attempted to train a brain decoding model that would generalize...
Article
Full-text available
13,15 ✉ 16p11.2 and 22q11.2 Copy Number Variants (CNVs) confer high risk for Autism Spectrum Disorder (ASD), schizophrenia (SZ), and Attention-Deficit-Hyperactivity-Disorder (ADHD), but their impact on functional connectivity (FC) remains unclear. Here we report an analysis of resting-state FC using magnetic resonance imaging data from 101 CNV carr...
Article
Introduction Beyond abnormal activity of focal brain areas, 1 aberrant functional interactions between brain regions are thought to be a core feature of schizophrenia. 2-4 Among the current issues related to this influential idea is whether abnormal functional connectivity in patients with schizophrenia is context-dependent. 5 Resting-state fMRI ch...
Article
Our objective was to assess the generalizability, across sites and cognitive contexts, of schizophrenia classification based on functional brain connectivity. We tested different training-test scenarios combining fMRI data from 191 schizophrenia patients and 191 matched healthy controls obtained at 6 scanning sites and under different task conditio...
Article
Full-text available
Aging is a lifelong process that starts at birth. Throughout the course of their life, individuals are exposed to various levels of stimulating activities. A higher level of engagement in such activities is suspected to protect against the normal course of cognitive aging or the cognitive manifestations of age-related brain diseases. However, the e...
Article
Full-text available
13,15 ✉ 16p11.2 and 22q11.2 Copy Number Variants (CNVs) confer high risk for Autism Spectrum Disorder (ASD), schizophrenia (SZ), and Attention-Deficit-Hyperactivity-Disorder (ADHD), but their impact on functional connectivity (FC) remains unclear. Here we report an analysis of resting-state FC using magnetic resonance imaging data from 101 CNV carr...
Article
Data-driven parcellations are widely used for exploring the functional organization of the brain, and also for reducing the high dimensionality of fMRI data. Despite the flurry of methods proposed in the literature, functional brain parcellations are not highly reproducible at the level of individual subjects, even with very long acquisitions. Some...
Preprint
Full-text available
Transfer learning has been a very active research topic in natural image processing. But few studies have reported notable benefits of transfer learning on medical imaging. In this study, we sought to investigate the transferability of deep artificial neural networks (DNN) in brain decoding, i.e. inferring brain state using fMRI brain response over...
Preprint
Many imaging and genetics studies have aimed to clarify whether the brain acts as an intermediate phenotype mediating the influence of genes in human behaviour. Brain activations in response to task demands are heterogeneous at the individual level, but also follow common patterns at the group level. Some studies have addressed this tension between...
Preprint
Full-text available
Cognitive decline occurs in healthy and pathological aging, and both may be preceded by subtle changes in the brain - offering a basis for cognitive predictions. Previous work has largely focused on predicting a diagnostic label from structural brain imaging. Our study broadens the scope of applications to cognitive decline in healthy aging by pred...
Preprint
Full-text available
Functional connectivity (FC) analyses of individuals with autism spectrum disorder (ASD) have established robust alterations of brain connectivity at the group level. Yet, the translation of these imaging findings into robust markers of individual risk is hampered by the extensive heterogeneity among ASD individuals. Here, we report an FC endopheno...
Article
Full-text available
The impact of multisite acquisition on rsfMRI connectivity has recently gained attention. We provide consistency values (Pearson's correlation) between resting-state fMRI (rsfMRI) connectivity maps of an adult volunteer (Csub) scanned 25 times over 3.5 years at 13 sites using the Canadian Dementia Imaging Protocol (CDIP, www.cdip-pcid.ca). This dat...
Preprint
Full-text available
A key goal in neuroscience is to understand brain mechanisms of cognitive functions. An emerging approach is brain decoding, which consists of inferring a set of experimental conditions performed by a participant, using pattern classification of brain activity. Few works so far have attempted to train a brain decoding model that would generalize ac...
Preprint
Full-text available
Our understanding of the changes in functional brain organization in autism is hampered by the extensive heterogeneity that characterizes this neurodevelopmental disorder. Data driven clustering offers a straightforward way to decompose this heterogeneity into subtypes of distinguishable connectivity types and promises an unbiased framework to inve...
Preprint
Full-text available
Copy number variants (CNVs) are among the most highly penetrant genetic risk factors for neuropsychiatric disorders. Their impact on brain connectivity remains mostly unstudied. Because they confer risk for overlapping conditions, we hypothesized that they may converge on shared connectivity patterns. We performed connectome-wide analyses using res...
Article
The topological organization of the brain, governed by the capacity of brain regions to synchronize their activity, allows for cost-effective performance during everyday cognitive activity. Functional connectivity is an fMRI method deemed task-specific and demanddependent. While the brain undergoes significant changes during healthy aging, conceptu...
Preprint
Full-text available
We describe the creation of an open science dataset from a cohort of cognitively unimpaired aging individuals with a parental or multiple-sibling history of Alzheimer′s disease (AD). Our purpose was to enable PResymptomatic EValuation of Novel or Experimental Treatments for AD (PREVENT-AD). To characterize this population, possibly progressing in t...
Preprint
Full-text available
Data-driven parcellations are widely used for exploring the functional organization of the brain, and also for reducing the high dimensionality of fMRI data. Despite the flurry of methods proposed in the literature, functional brain parcellations are not highly reproducible at the level of individual subjects, even with very long acquisitions. Some...
Article
Full-text available
Automatic alignment of brain anatomy in a standard space is a key step when processing magnetic resonance imaging for group analyses. Such brain registration is prone to failure, and the results are therefore typically reviewed visually to ensure quality. There is however no standard, validated protocol available to perform this visual quality cont...
Article
Full-text available
Increasing the reproducibility of neuroimaging measurement addresses a central impediment to the advancement of human neuroscience and its clinical applications. Recent efforts demonstrating variance in functional brain organization within and between individuals shows a need for improving reproducibility of functional parcellations without long sc...
Article
Full-text available
Aetiological and clinical heterogeneity is increasingly recognized as a common characteristic of Alzheimer's disease and related dementias. This heterogeneity complicates diagnosis, treatment, and the design and testing of new drugs. An important line of research is discovery of multimodal biomarkers that will facilitate the targeting of subpopulat...
Preprint
Full-text available
16p11.2 and 22q11.2 Copy Number Variants (CNVs) confer high risk for Autism Spectrum Disorder (ASD), schizophrenia (SZ), and Attention-Deficit-Hyperactivity-Disorder (ADHD), but their impact on functional connectivity (FC) remains unclear. We analyzed resting-state functional magnetic resonance imaging data from 101 CNV carriers, 755 individuals wi...
Article
Full-text available
Beginning in the early stages of Alzheimer’s disease (AD), the hippocampus reduces its functional connections to other cortical regions due to synaptic depletion. However, little is known regarding connectivity abnormalities within the hippocampus. Here, we describe rostral-caudal hippocampal convergence (rcHC), a metric of the overlap between the...
Article
Full-text available
Introduction: The Consortium for the early identification of Alzheimer's disease-Quebec (CIMA-Q) created a research infrastructure to recruit, characterize, and track disease progression in individuals at risk of dementia. Methods: CIMA-Q established standardized clinical, neuropsychological, neuroimaging, blood (plasma, serum, RNA, genomic DNA)...
Article
Full-text available
We present MRI data from a single human volunteer consisting in over 599 multi-contrast MR images (T1-weighted, T2-weighted, proton density, fluid-attenuated inversion recovery, T2* gradient-echo, diffusion, susceptibility-weighted, arterial-spin labelled, and resting state BOLD functional connectivity imaging) acquired in over 73 sessions on 36 di...
Preprint
Full-text available
Etiological and clinical heterogeneity is increasingly recognized as a common characteristic of Alzheimer′s disease and related dementias. This heterogeneity complicates diagnosis, treatment, and the design and testing of new drugs. An important line of research is discovery of multimodal biomarkers that will facilitate the targeting of subpopulati...
Article
Full-text available
Studies using resting-state functional magnetic resonance imaging (rsfMRI) are increasingly collecting data at multiple sites in order to speed up recruitment or increase sample size. The main objective of this study was to assess the long-term consistency of rsfMRI connectivity maps derived at multiple sites and vendors using the Canadian Dementia...
Preprint
Automatic alignment of brain anatomy in a standard space is a key step when processing magnetic resonance imaging for group analyses. Such brain registration is prone to failure, and the results are therefore typically reviewed visually to ensure quality. There is however no standard, validated protocol available to perform this visual quality cont...
Article
Full-text available
Major hardware/software changes to MRI platforms, either planned or unplanned, will almost invariably occur in longitudinal studies. Our objective was to assess the resulting variability on relevant imaging measurements in such context, specifically for three Siemens Healthcare Magnetom Trio upgrades to the Prisma fit platform. We report data acqui...
Poster
Full-text available
Observed variability in morphometric imaging trajectories can be distinguished into separate classes that are potentially associated with later clinical phenotypes. Volumetric trajectory classes vary by sex and are selectively moderated by APOE risk. The specificity of these groups is important for precision health protocols.
Article
Full-text available
The harmonized Canadian Dementia Imaging Protocol (CDIP) has been developed to suit the needs of a number of co-occurring Canadian studies collecting data on brain changes across adulthood and neurodegeneration. In this study, we verify the impact of CDIP parameters compliance on total brain volume variance using 86 scans of the same individual acq...