Portrait of Guillaume Dumas

Guillaume Dumas

Associate Academic Member
Associate Professor, Université de Montréal, Department of Psychiatry and Addiction
Adjunct Professor, McGill University, Department of Psychiatry
Research Topics
Computational Biology
Computational Neuroscience
Deep Learning
Dynamical Systems
Machine Learning Theory
Medical Machine Learning
Reinforcement Learning
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Biography

Guillaume Dumas is an associate professor of computational psychiatry in the Faculty of Medicine, Université de Montréal, and principal investigator in the Precision Psychiatry and Social Physiology laboratory at the Centre hospitalier universitaire (CHU) Sainte-Justine Research Centre. He holds the IVADO professorship for AI in Mental Health, and the Fonds de recherche du Québec - Santé (FRQS) J1 in AI and Digital Health. In 2023, Dumas was recognized as a CIFAR Azrieli Global Scholar – Brain, Mind, and Consciousness program, and nominated as a Future Leader in Canadian Brain Research by the Brain Canada Foundation.

Dumas was previously a permanent researcher in neuroscience and computational biology at the Institut Pasteur (Paris). Before that, he was a postdoctoral fellow at the Center for Complex Systems and Brain Sciences (Florida Atlanta University). He holds an engineering degree in advanced engineering and computer science (École Centrale Paris), two MSc degrees (theoretical physics, Paris-Saclay University; cognitive science, ENS/EHESS/Paris 5), and a PhD in cognitive neuroscience (Sorbonne University).

The goal of his research is to cross-fertilize AI/ML, cognitive neuroscience and digital medicine through an interdisciplinary program with two main axes:

- AI/ML for Mental Health, which aims to create new algorithms to investigate the development of human cognitive architecture and deliver personalized medicine in neuropsychiatry using data from genomes to smartphones.

- Social Neuroscience for AI/ML, which translates basic brain research and dynamical systems formalism into neurocomputational and machine learning hybrid models (NeuroML) and machines with social learning abilities (Social NeuroAI & HMI).

Current Students

Saskia Helbling
Postdoctorate - Université de Montréal
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Mahta Ramezanian
Master's Research - Université de Montréal
Principal supervisor :
Irina Rish
Pascal Tikeng Notsawo
PhD - Université de Montréal
Principal supervisor :
Guillaume Rabusseau
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Tommaso Tosato
Postdoctorate - Université de Montréal
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Google Scholar

Publications

Asymmetric developmental bifurcations in polarized environments: a new class of human variants, which may include autism.
Laurent Mottron
Alix Lavigne-Champagne
Boris C. Bernhardt
Guillaume Dumas
Sébastien Jacquemont
D. Gagnon
2025-09-29
Molecular Psychiatry (published)
doi.org
Asymmetric developmental bifurcations in polarized environments: a new class of human variants, which may include autism.
Laurent Mottron
Alix Lavigne-Champagne
Boris C. Bernhardt
Guillaume Dumas
Sébastien Jacquemont
D. Gagnon
2025-09-29
Molecular Psychiatry (published)
doi.org
Acute respiratory distress syndrome in patients with cancer: the YELENNA prospective multinational observational cohort study.
Peter Schellongowski
Michael Darmon
Philipp Eller
Laveena Munshi
Tobias Liebregts
Victoria Metaxa
Luca Montini
Tobias Lahmer
F. Taccone
Andry Van de Louw
Martin Balik
P. Pickkers
Pleun Hemelaar
Hemang Yadav
Andreas Barratt-Due
T. Karvunidis
Jordi Riera
G. Martucci
I. Martín-Loeches
Pedro Castro … (see 6 more)
Nina Buchtele
Virginie Lemiale
Stefan Hatzl
Guillaume Dumas
T. Staudinger
Elie Azoulay
2025-09-25
Intensive Care Medicine (published)
doi.org
Acute respiratory distress syndrome in patients with cancer: the YELENNA prospective multinational observational cohort study.
Peter Schellongowski
Michael Darmon
Philipp Eller
Laveena Munshi
Tobias Liebregts
Victoria Metaxa
Luca Montini
Tobias Lahmer
F. Taccone
Andry Van de Louw
Martin Balik
P. Pickkers
Pleun Hemelaar
Hemang Yadav
Andreas Barratt-Due
T. Karvunidis
Jordi Riera
G. Martucci
I. Martín-Loeches
Pedro Castro … (see 6 more)
Nina Buchtele
Virginie Lemiale
Stefan Hatzl
Guillaume Dumas
T. Staudinger
Elie Azoulay
2025-09-25
Intensive Care Medicine (published)
doi.org
Pathfinding: a neurodynamical account of intuition
Steven Kotler
Michael Mannino
Karl Friston
Gyorgy Buzsáki
J. A. Scott Kelso
Guillaume Dumas
2025-08-13
Communications Biology (published)
doi.org
Persistent Instability in LLM's Personality Measurements: Effects of Scale, Reasoning, and Conversation History
Tommaso Tosato
Saskia Helbling
Yorguin-Jose Mantilla-Ramos
Mahmood Hegazy
Alberto Tosato
D. Lemay
Irina Rish
Guillaume Dumas
2025-08-06
ArXiv (preprint)
doi.org
arxiv.org
Persistent Instability in LLM's Personality Measurements: Effects of Scale, Reasoning, and Conversation History
Tommaso Tosato
Saskia Helbling
Yorguin-Jose Mantilla-Ramos
Mahmood Hegazy
Alberto Tosato
D. Lemay
Irina Rish
Guillaume Dumas
Large language models require consistent behavioral patterns for safe deployment, yet their personality-like traits remain poorly understood… (see more). We present PERSIST (PERsonality Stability in Synthetic Text), a comprehensive evaluation framework testing 25+ open-source models (1B-671B parameters) across 500,000+ responses. Using traditional (BFI-44, SD3) and novel LLM-adapted personality instruments, we systematically vary question order, paraphrasing, personas, and reasoning modes. Our findings challenge fundamental deployment assumptions: (1) Even 400B+ models exhibit substantial response variability (SD>0.4); (2) Minor prompt reordering alone shifts personality measurements by up to 20%; (3) Interventions expected to stabilize behavior, such as chain-of-thought reasoning, detailed personas instruction, inclusion of conversation history, can paradoxically increase variability; (4) LLM-adapted instruments show equal instability to human-centric versions, confirming architectural rather than translational limitations. This persistent instability across scales and mitigation strategies suggests current LLMs lack the foundations for genuine behavioral consistency. For safety-critical applications requiring predictable behavior, these findings indicate that personality-based alignment strategies may be fundamentally inadequate.
2025-08-06
ArXiv (preprint)
arxiv.org
arxiv.org
Posttraumatic Growth in Intensive Care Unit Health Care Professionals After COVID-19
Elie Azoulay
Laurent Argaud
Vincent Labbé
Guillaume Dumas
Fabrice Bruneel
Mercé Jourdain
Christophe Guitton
Amélie Seguin
Samir Jaber
David Schnell
Isabelle Vinatier
Fanny Ardisson
Michel Ramakers
Antoine Herault
Olivier Lesieur
Alain Cariou
Antoine Vieillard-Baron
Olivier Guisset
Frédéric Pochard
Michael Darmon … (see 1 more)
Nancy Kentish-Barnes
2025-08-01
JAMA Network Open (published)
doi.org
Posttraumatic Growth in Intensive Care Unit Health Care Professionals After COVID-19
Elie Azoulay
Laurent Argaud
Vincent Labbé
Guillaume Dumas
Fabrice Bruneel
Mercé Jourdain
Christophe Guitton
Amélie Seguin
Samir Jaber
David Schnell
Isabelle Vinatier
Fanny Ardisson
Michel Ramakers
Antoine Herault
Olivier Lesieur
Alain Cariou
Antoine Vieillard-Baron
Olivier Guisset
Frédéric Pochard
Michael Darmon … (see 1 more)
Nancy Kentish-Barnes
This cross-sectional study investigates positive psychological changes after adversity, known as posttraumatic growth, in health care profes… (see more)sionals who worked in intensive care units (ICUs) during the COVID-19 pandemic in France and Belgium.
2025-08-01
JAMA Network Open (published)
doi.org
Parsing Autism Heterogeneity: Transcriptomic Subgrouping of Imaging-Derived Phenotypes in Autism.
Johanna Leyhausen
Caroline Gurr
Lisa M. Berg
Hanna Seelemeyer
Bassem Hermila
Tim Schäfer
Andreas Chiocchetti
Charlotte M. Pretzsch
Eva Loth
Beth Oakley
Jan K. Buitelaar
Christian Beckmann
Tony Charman
Thomas Bourgeron
Eli Barthome
Tobias Banaschewski
Jumana Ahmad
Sara Ambrosino
Bonnie Auyeung
Simon Baron-Cohen … (see 56 more)
Sarah Baumeister
Sven Bölte
Carsten Bours
Michael Brammer
Daniel Brandeis
Claudia Brogna
Yvette de Bruijn
Bhismadev Chakrabarti
Ineke Cornelissen
Daisy Crawley
Flavio Dell’Acqua
Guillaume Dumas
Sarah Durston
Christine Ecker
Jessica Faulkner
Vincent Frouin
Pilar Garcés
David Goyard
Lindsay Ham
Hannah Hayward
Joerg F. Hipp
Rosemary Holt
Mark Johnson
Emily J. H. Jones
Prantik Kundu
Meng-Chuan Lai
Xavier Liogier D’ardhuy
Michael V. Lombardo
David J. Lythgoe
René Mandl
Andre Marquand
Luke Mason
Maarten Mennes
Andreas Meyer-Lindenberg
Carolin Moessnang
Nico Bast
Larry O’Dwyer
Marianne Oldehinkel
Bob Oranje
Gahan Pandina
Antonio Persico
Barbara Ruggeri
Amber N. V. Ruigrok
Jessica Sabet
Roberto Sacco
Antonia San José Cáceres
Emily Simonoff
Will Spooren
Julian Tillmann
Roberto Toro
Heike Tost
Jack Waldman
Steve C. R. Williams
Caroline Wooldridge
Marcel P. Zwiers
Declan Murphy
2025-07-01
Biological Psychiatry: Cognitive Neuroscience and Neuroimaging (published)
doi.org
Impact de l'antibiothérapie par Daptomycine dans le traitement des bactériémies à Enterococcus faecium en réanimation : l'étude rétrospective multicentrique ENTERODAPTO.
S. Herbel
Guillaume Dumas
L. Chantelot
J. Massol
Q. Moyon
J. Ricard
E. Azoulay
C. Hauw-Berlemont
E. Maury
T. Urbina
2025-06-01
Médecine et Maladies Infectieuses Formation (published)
doi.org
A systematic review of hyperscanning in clinical encounters
Lena Adel
Lisane Moses
Elisabeth Irvine
Kyle T Greenway
Guillaume Dumas
Michael Lifshitz
2025-06-01
Neuroscience and Biobehavioral Reviews (published)
doi.org