Portrait de Guillaume Dumas

Guillaume Dumas

Membre académique associé
guillaume.dumas@mila.quebec
Professeur agrégé, Université de Montréal, Département de psychiatrie et d’addictologie
Professeur adjoint, McGill University, Département de psychiatrie
Sujets de recherche
Apprentissage automatique médical
Apprentissage par renforcement
Apprentissage profond
Biologie computationnelle
Neurosciences computationnelles
Systèmes dynamiques
Théorie de l'apprentissage automatique
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Biographie

Guillaume Dumas est professeur agrégé de psychiatrie computationnelle à la Faculté de médecine de l'Université de Montréal et chercheur principal du laboratoire de psychiatrie de précision et de physiologie sociale du Centre de recherche du CHU Sainte-Justine. Il est titulaire de la chaire IVADO IA en santé mentale et chercheur-boursier junior 1 du Fonds de recherche du Québec - Santé (FRQS) dans le domaine de l’ IA en santé et de la santé numérique. En 2023, il a été retenu dans le cadre du Programme des chercheurs mondiaux CIFAR-Azrieli pour le programme de recherche Cerveau, esprit et conscience. Il a également été nommé parmi les Futurs leaders canadiens de la recherche sur le cerveau par la Fondation Brain Canada.

Il a auparavant été chercheur permanent en neurosciences et en biologie computationnelle à l'Institut Pasteur (Paris, France), ainsi que chercheur postdoctoral au Center for Complex Systems and Brain Sciences à l’Université Florida Atlantic (FAU), aux États-Unis. Il est titulaire d'un diplôme d'ingénieur en ingénierie avancée et informatique (École centrale Paris), de deux masters (physique théorique, Université Paris-Saclay; sciences cognitives, ENS/EHESS/Paris 5) et d'un doctorat en neurosciences cognitives (Sorbonne Université).

Ses recherches visent à combiner l’intelligence artificielle, les neurosciences cognitives et la médecine numérique à travers un programme interdisciplinaire suivant deux axes principaux :

- L’intelligence artificielle en santé mentale, par la création de nouveaux algorithmes pour étudier le développement de l'architecture cognitive humaine et pour fournir une médecine personnalisée en neuropsychiatrie grâce à des données allant du génome à celles des téléphones intelligents;

- Les neurosciences sociales en intelligence artificielle, par la traduction de la recherche fondamentale sur le cerveau et le formalisme des systèmes dynamiques en des modèles hybrides neurocomputationnels et d’apprentissage automatique (NeuroML) et de nouvelles architectures présentant des capacités d'apprentissage social (NeuroIA Sociale et IHM).

Étudiants actuels

Nadine Mohamed
Maîtrise recherche - UdeM
nadine.mohamed@mila.quebec
Rémy Ramadour
Visiteur de recherche indépendant - CHU Sainte Justine / Université de Montréal
remy.ramadour.hsj@ssss.gouv.qc.ca
Site web
Github
Mahta Ramezanian
Maîtrise recherche - UdeM
Superviseur⋅e principal⋅e :
Irina Rish
mahta.ramezanian@mila.quebec
Pascal Tikeng Notsawo
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Guillaume Rabusseau
pascal.tikeng@mila.quebec
Site web
Github
Google Scholar

Publications

Beyond the ICP value: neurocritical care in severe bacterial meningitis- Authors’ reply
Guillaume Dumas
Cindy Poirier
Benoit Champigneulle
2026-10-31
The Lancet Regional Health - Europe (publié)
doi.org
Positive interactions and active mentalizing facilitate inter-brain synchronization in couples
Isabella Schneider
Quentin Moreau
Daniel Neudecker
Sabine Christiane Herpertz
Guillaume Dumas
High-quality interactions rely on socio-cognitive abilities, which help partners understand and respond to one another. Hyperscanning, which… (voir plus) measures brain activity in multiple individuals simultaneously, can examine inter-brain synchronization as a possible signature of social coordination. In this study, we explore this synchronization during natural, everyday interactions in romantic couples. Forty-two dyads participated in a naturalistic behavioral paradigm while EEG was recorded. We measured behavioral dyadic reciprocity and negative states, and computed inter-brain synchronization using the circular correlation coefficient (CCorr) across multiple frequency bands (Theta [4-8 Hz], Alpha [8-13 Hz], and Beta [14-31 Hz]). Positive interactions elicited greater dyadic reciprocity and fewer negative states compared to negative interactions. At the neural level, inter-brain synchronization in the beta band was significantly higher during positive compared to negative interactions. Mentalizing compared to counting elicited increased inter-brain synchronization in both alpha and beta bands, indicating that active sociocognitive processing enhances neural alignment between partners. These findings demonstrate that inter-brain dynamics provide a neural signature of both interaction valence and mentalizing engagement during real-world social interactions, putting forward inter-brain synchronization as a sensitive marker of sociocognitive coordination.
2026-10-02
Social Cognitive and Affective Neuroscience (publié)
doi.org
Quantum computing for neuroscience: opportunities beyond classical limits
Annemarie Wolff
Alexandre Choquette
Georg Northoff
Atsushi Iriki
Guillaume Dumas
2026-09-23
Nature Reviews Neuroscience (publié)
doi.org
Recovery from disorders of consciousness: Lesions and GABAergic modulation in a biologically inspired spiking neural network
Francesco Achilli
Antoine Cautru
Jean‐Pierre Changeux
Guillaume Dumas
The effects of positive allosteric modulators (PAMs) of the GABA A receptor in disorders of consciousness (DoC)—such as the hypnotic zolpi… (voir plus)dem in coma—are frequently reported but remain poorly understood. Although several hypotheses have been proposed to explain their paradoxical effect, biologically plausible computational models that test why only a subset of patients with DoC respond to inhibitory-enhancing medications may clarify this phenomenon and guide therapeutic strategies. We extended a spiking neural network model to mechanistically investigate inhibitory neuron enhancement in DoC. The model featured biologically inspired elements, including a ratio of 80:20 excitatory-to-inhibitory neurons and 12 Hz of spontaneous intrinsic activity. Neurons were spatially organized, and the network performed a trace conditioning task to investigate conscious access. We implemented localized and diffuse lesions affecting excitatory and inhibitory neuron populations, individually and in combination. The positive allosteric modulation of GABA A receptors was simulated by increasing inhibitory synaptic weights. Experiments revealed distinct recovery patterns depending on damage type and lesion distribution. Spontaneous recovery was more impaired by excitatory than inhibitory lesions, with local lesions generally affecting performance more than diffuse ones. Inhibitory postsynaptic potentiation produced dose-dependent recovery after inhibitory lesions, with therapeutic windows varying by lesion type. Our findings suggest that the paradoxical effect of GABA A receptor PAMs arises from the restoration of excitatory–inhibitory balance when inhibitory networks are moderately disrupted. This computational framework offers a testable account in which insufficient inhibitory regulation represents a common pathway underlying DoC cases responsive to GABA A receptor PAMs across diverse etiologies.
2026-09-21
Proceedings of the National Academy of Sciences (publié)
doi.org
Time to redefine psychosis: completing an integral conceptualization
Emmanuel Stip
Alexandre Hudon
Guillaume Dumas
Alexandre Dumais
To the Editor,We read with great interest the article An Integral Conceptualization of Psychosis (Benning, 2026). By integrating biological,… (voir plus) psychological, phenomenological, cultural, and social pe...
2026-09-09
Psychosis (publié)
doi.org
Heterogeneity of brain dynamics in genetic and psychiatric conditions
Adrien E. E. Dubois
Sarah Lippé
Charles-Olivier Martin
Inga Sophia Knoth
Valerie Fontaine
Anne-Marie Bélanger
Pascale Abadie
Melissa T. Carter
Mélanie Couture
Mayada Elsabbagh
Alan Evans
Carl Ernst
Baudouin Forgeot d’Arc
Ridha Joober
Guy Rouleau
Julie Scorah
Christine Tardif
Ma'n H Zawati
Grace Westerkamp
Ernest V. Pedapati … (voir 11 de plus)
Craig Erickson
Borja Rodríguez‐Herreros
Nadia Chabane
Kenza Latreche
Marie Schaer
Aline Lefebvre
Richard Delorme
Sara Jane Webb
James C. McPartland
Sébastien Jacquemont
Guillaume Dumas
Abstract Whether the heterogeneity of psychiatric conditions converges on shared neurophysiological alterations or translates into distinct … (voir plus)signatures remains unclear. We assembled high-density electroencephalogram (hd-EEG) resting-state recordings from 4,812 individuals aged 5 months to 66 years across 11 psychiatric conditions, a broad spectrum of rare genetic variants, and typically developing (TD) individuals. We established normative developmental trajectories of source-space EEG across spectral organization, connectivity, and signal complexity. Psychiatric conditions showed small deviations, revealing a shared transdiagnostic profile. In contrast, single rare variants showed substantially larger, distinct and sometimes mirror-opposite signatures that collapsed toward the psychiatric profile when pooled. Autism Spectrum Disorder showed some of the smallest group-level effects yet the largest individual deviations, indicating substantial but directionally inconsistent alterations. EEG deviations followed a cortical gradient, with larger effects in sensorimotor regions. We demonstrate that sample sizes in the hundreds are required for robust associations with psychiatric diagnoses. This interactive open resource provides normative scores to benchmark future results.
2026-09-07
bioRxiv (accepté)
doi.org
Temporal coupling as a design principle for social AI
Annemarie Wolff
Vincent Chamberland
Guillaume Dumas
Despite their ability to emulate social reasoning, current AI systems consistently fail at the dynamic, real-time coordination that defines … (voir plus)human social interaction. We argue this failure reflects a missing aspect in their design, not a limitation of scale or training data. Current AI systems model their partner from the outside and train on the data from interactions. Social intelligence, however, is not a property of an individual. It emerges when two coupled individuals interact and is developed through that coupling. We here argue that social AI should be built, and evaluated, as a coupled system with a human which targets an optimal, rather than maximal, alignment. This argument is based on two principles from research in social neuroscience. First, the training objective must change from predicting their interacting partner to a directed coupling that optimizes synchrony. Second, optimizing synchrony requires an embodied and organized temporal architecture which separates faster interactive generation with slower contextual comprehension. We show how coupling can be measured against benchmarks of human interaction and argue that this framing is a safety requirement. Together, these principles offer a neurobiologically grounded pathway toward AI systems capable of real-time social coordination with human partners.
2026-08-30
Zenodo (prépublication)
doi.org
Outcomes of patients with Waldenström macroglobulinemia in ICU: a retrospective multicentric study
Camille Barraud
Aalliayah Velletrie
Stéphanie Harel
Frédéric Pène
Julien Charpentier
Antoine Guillon
Elie Azoulay
Michael Darmon
Emmanuel Canet
Anne-Sophie Moreau
Guillaume Dumas
Lucie Biard
Lara Zafrani
BACKGROUND Waldenström macroglobulinemia (WM) is a rare lymphoplasmacytic lymphoma, that can lead to life-threatening complications requiri… (voir plus)ng intensive care unit (ICU) admission. This study aimed to describe the clinical characteristics, WM-specific complications, and outcomes of WM patients admitted to the ICU. METHODS We conducted a multicenter retrospective study in 6 French ICUs including all patients with WM admitted between 2010 and 2024. The primary outcome was ICU mortality, analyzed using Ridge logistic regression. One-year mortality and associated risk factors were also assessed after ICU admission. RESULTS A total of 151 patients with WM were admitted to the ICU over the 14-year period. ICU mortality was 20% (n = 30), with infections being the leading cause of death. The main reason for admission was acute respiratory failure, and nearly half of the patients presented with sepsis at admission. The most WM-specific complications included hyperviscosity syndrome (n = 29, 19%) and other IgM-related vascular complications (n = 27, 18%). In Ridge logistic regression, a higher SOFA score (β = 0.099) and autoimmune haemolytic anemia (β = 0.058) were most strongly associated with ICU mortality, whereas, hyperviscosity syndrome (β = -0.045) showed the strongest negative association. The one-year mortality rate was 40% (n = 58) and remission at one year was achieved in 47% (n = 56) of treated patients. CONCLUSION This is the first large retrospective cohort of critically ill patients with WM. SOFA score and autoimmune cytopenias were most strongly associated with ICU mortality, highlighting the importance of both disease-specific complications and baseline severity, and supporting the need for tailored prognostic tools and individualized management strategies.
2026-08-28
Journal of Critical Care (publié)
doi.org
Emotion reconfigures neuronal coordination across brains to control social choice
Francesco Papaleo
Federica Antonelli
Anna Monai
Fabrizio Bernardi
Atesh Koul
Nicola Marie Engel
Ilaria Carta
Francesca Managò
Arianna Benedetti
Anna Maria Borruto
LUDOVICO SPATTINI
Federica Maltese
Chunzhi Yi
Gian Marco Leggio
Guillaume Dumas
Stefano Panzeri
Giacomo Novembre
2026-08-27
Research Square (publié)
doi.org
Green light exposure reduces central sensitization in cats with osteoarthritis-associated somatosensory impairment
Aliénor Delsart
Aude Castel
Guillaume Dumas
Frédéric Sauvé
Colombe Otis
Bertrand Lussier
Franck Péron
Marc Hébert
Nicolas Lapointe
Nicolas Quaegebeur
Pierre Grandjean
Maxim Moreau
Johanne Martel-Pelletier
Jean‐Pierre Pelletier
Eric Troncy
In humans, chronic pain is associated with multisensory hypersensitivity, which can be modulated by sensorial exposure. Although cats experi… (voir plus)ence chronic pain, their sensorial perception under this condition has never been investigated. Adult neutered healthy ( n = 6) or osteoarthritic ( n = 32) cats were assessed for functional alteration, central sensitization, and sensorial (olfactory and auditory) tolerance. The effects of specific light wavelengths were tested for neuromodulation via visual exposure. Hypersensitized cats displayed stronger unpleasant odor avoidance and lower sensitivity to repeated repulsive sounds. Odor avoidance correlated with delta and theta band proportions, inverse markers of endogenous inhibitory control. Functional alteration correlated with beta activity, a pain marker. After green light exposure, neuro-sensitization decreased for 80% of the less sensitized cats, and delta and theta band proportions increased further (no longer requiring inhibition), while beta and gamma band proportions decreased. Neuro-sensitization appears central in feline osteoarthritis pain, is associated with sensorial modifications, and is modulable by non-pharmacological approaches.
2026-08-26
iScience (publié)
doi.org
Social interactions between people of same and different generations shape longitudinal changes in interpersonal neural synchrony, loneliness, and social connection
Ryssa Moffat
Guillaume Dumas
Emily S. Cross
Loneliness is globally acknowledged as a severe and burgeoning health risk, fueling interest in helping people of all ages form meaningful s… (voir plus)ocial connections. One promising approach consists of intergenerational social programs. While behavioral and qualitative evidence derived from such programs promise health and wellbeing benefits, the physiological consequences of repeated intergenerational encounters remain unknown. Insight into physiological changes will shed light on the mechanisms of social connection. We charted longitudinal changes in interpersonal neural synchrony (INS) in 31 intergenerational (older/younger adult) and 30 same-generation (younger adult) dyads across a six-session creative drawing program. At each session, dyads completed self-report measures, drew together and alone, and had their cortical activation recorded with fNIRS. In both groups, INS was greater while dyads drew together than alone. Across sessions, intergenerational dyads' INS decreased and same-generation dyads' INS increased. INS in RIFG~RTPJ and RIFG~RIFG were predictive of loneliness levels and feelings of social closeness, respectively. This exploratory longitudinal research reinforces the multi-faceted nature of INS dynamics as social connections are forged.
2026-08-19
PLOS Biology (publié)
doi.org
Tuning in together: LSD enhances inter-brain synchrony and felt connectedness in romantic couples
Natasha L. Mason
Artur Czeszumski
Iva Totomanova
Filip Trbusek
Mauro Cavarra
Steph Ashton
Stefan Toennes
Eef Theunissen
Johannes Reckweg
P. L. Lockwood
Marieke DeWitte
Katrin Preller
Kim Kuypers
Guillaume Dumas
Pablo Mallaroni
Jan Ramaekers
Abstract Social connection is fundamental to human wellbeing. Serotonergic psychedelics such as lysergic acid diethylamide (LSD) acutely hei… (voir plus)ghten subjective connectedness, yet their effects on real-time social connection remain poorly understood. Using EEG hyperscanning in a randomized, double-blind, placebo-controlled crossover study, we recorded neural activity simultaneously from both members of healthy romantic couples (N=25) who received LSD (50 μg) or placebo together, across resting and interactive states. LSD increased subjective connectedness, including feelings of love, closeness, trust, and being “in sync,” while reducing loneliness, compared to placebo. This affiliative shift dissociated from the drug’s pharmacokinetic time-course, remaining elevated as subjective intensity and plasma concentration declined. In parallel, LSD increased inter-brain synchrony during shared rest, carried specifically by theta-band amplitude-envelope coupling. Importantly, this effect survived two complementary controls. First, it exceeded coupling between unrelated individuals and second the effects depended on contemporaneous neural alignment rather than shared drug-induced dynamics. Exploratory analyses showed that romantic partners with greater resting synchrony reported greater feelings of connectedness. These findings provide the first evidence that a psychedelic enhances brain-to-brain coupling between people, linking a pharmacologically induced state of felt connection to a measurable signature shared across interacting brains.
2026-08-17
bioRxiv (prépublication)
doi.org