Pour savoir comment effectuer et gérer un dépôt de document, consultez le « Guide abrégé – Dépôt de documents » sur le site Web de la Bibliothèque. Pour toute question, écrivez à corpus@ulaval.ca.
 

Personne :
Hétu, Sébastien

En cours de chargement...
Photo de profil

Adresse électronique

Date de naissance

Projets de recherche

Structures organisationnelles

Fonction

Nom de famille

Hétu

Prénom

Sébastien

Affiliation

École de psychologie, Faculté des sciences sociales, Université Laval

ISNI

ORCID

Identifiant Canadiana

ncf11879322

person.page.name

Résultats de recherche

Voici les éléments 1 - 8 sur 8
  • PublicationAccès libre
    Approche écologique et multi-modale pour étudier l'observation d'actions
    (2014) Hétu, Sébastien; Jackson, Philip L.; Mercier, Catherine
    Lors de l’observation de mouvements, le système perception-action permet le couplage entre les représentations visuelle et motrice du mouvement observé. Ce couplage produit des effets de facilitation motrice qui pourraient être utilisés pour entraîner le système moteur chez différentes populations cliniques. Cette thèse se propose comme un pont entre la recherche fondamentale et l’utilisation clinique de l’observation d’actions. Son objectif principal était de vérifier si les effets produits par l’observation de mouvements simples pouvaient être reproduits en utilisant des mouvements de la vie courante. Pour ce faire, les effets de l’observation d’actions ont été étudiés chez des sujets sains à l’aide d’approches tenant compte des intérêts de la réadaptation. Cette thèse devait également fournir des données sur les différences dans la réponse à l’observation d’actions entre les individus et entre les méthodes utilisées pour la mesurer. Les résultats suggèrent que le système perception-action est surtout recruté lors de l’observation de mouvements peu familiers. Aussi, nos données indiquent que l’observation de mouvements de la vie courante peut produire des patrons de facilitation anatomiquement congruents avec les mouvements observés. Nos données montrent également que la magnitude et le patron de réponse sont très variables entre les individus. De plus, les effets mesurés peuvent dépendre de la méthode utilisée pour étudier l’observation d’actions. Ainsi, il ne semble pas y avoir de relation directe entre les marqueurs comportementaux et physiologiques de la facilitation motrice induite par l’observation d’actions. À l’instar de ce qui avait été montré lors d’études utilisant des mouvements simples, l’observation de mouvements de la vie courante peut produire un patron de facilitation où la représentation du mouvement observé est associée à sa représentation dans le répertoire moteur de l’observateur. Les importantes différences inter-individuelles dans les effets suggèrent que certains individus répondent plus facilement que d’autres à l’observation d’actions. Par conséquent, identifier quels patients sont susceptibles de bénéficier le plus de l’observation d’actions en réadaptation pourrait permettre une utilisation plus efficiente de cette approche. Nous proposons qu’une étape importante du passage de l’observation d’actions vers la réadaptation sera l’identification des marqueurs qui peuvent le mieux prédire les améliorations cliniques.
  • PublicationRestreint
    Measuring how genetic and epigenetic variants can filter emotion perception
    (Clinical Neuroscience Publishers, 2015-10-01) Hétu, Sébastien; Jackson, Philip L.; Taschereau-Dumouchel, Vincent; Chagnon, Yvon C.
    Emotion perception has been extensively studied in cognitive neurosciences and stands as a promising intermediate phenotype of social cognitive processes and psychopathologies. Exciting imaging genetic studies have recently identified genetic and epigenetic variants affecting brain responses during emotion perception tasks, but characterizing how these variants interact and relate to higher-order cognitive processes remains a challenge. Here, we integrate works in parallel fields and propose a new psychophysical conceptualization to address this issue. This approach proposes to consider genetic variants as ‘filters’ of perceptual information that can interact to shape different perceptual profiles. Importantly, these perceptual profiles can be precisely described and compared between multivariate genetic groups using a new psychophysical method. Crucially, this approach represents a potentially powerful novel tool to address gene-by-gene and gene-by-environment interactions, and provides a new cognitive perspective to link social perceptive and social cognitive processes in the context of psychiatric disorders.
  • PublicationAccès libre
    BDNF Val66Met polymorphism is associated with self-reported empathy
    (Public Library of Science, 2016-02-22) Hétu, Sébastien; Jackson, Philip L.; Taschereau-Dumouchel, Vincent; Chagnon, Yvon C.; Bagramyan, Anaït; Labrecque, Alexandre; Racine, Marion
    Empathy is an important driver of human social behaviors and presents genetic roots that have been studied in neuroimaging using the intermediate phenotype approach. Notably, the Val66Met polymorphism of the Brain-derived neurotrophic factor (BDNF) gene has been identified as a potential target in neuroimaging studies based on its influence on emotion perception and social cognition, but its impact on self-reported empathy has never been documented. Using a neurogenetic approach, we investigated the association between the BDNF Val66Met polymorphism and self-reported empathy (Davis’ Interpersonal Reactivity Index; IRI) in a sample of 110 young adults. Our results indicate that the BDNF genotype is significantly associated with the linear combination of the four facets of the IRI, one of the most widely used self-reported empathy questionnaire. Crucially, the effect of BDNF Val66Met goes beyond the variance explained by two polymorphisms of the oxytocin transporter gene previously associated with empathy and its neural underpinnings (OXTR rs53576 and rs2254298). These results represent the first evidence suggesting a link between the BDNF gene and self-reported empathy and warrant further studies of this polymorphism due to its potential clinical significance.
  • PublicationRestreint
    Variability in the effector-specific pattern of motor facilitation during the observation of everyday actions : implications for the clinical use of action observation
    (Elsevier, 2010-07-13) Hétu, Sébastien; Jackson, Philip L.; Mercier, Catherine; Gagné, Martin
    Action observation is increasingly considered as a rehabilitation tool as it can increase the cortical excitability of muscles involved in the observed movements and therefore produce effector-specific motor facilitation. In order to investigate the action observation mechanisms, simple single joint intransitive movements have commonly been used. Still, how the observation of everyday movements which often are the prime target of rehabilitation affects the observer cortical excitability remains unclear. Using transcranial magnetic stimulations, we aimed at verifying if the observation of everyday movements made by the proximal or distal upper-limb produces effector-specific motor facilitation in proximal (arm) and distal (hand) muscles of healthy subjects. Results suggest that, similar to simple intransitive movements, observation of more complex everyday movements involving mainly the proximal or distal part of upper limb induces different patterns of motor facilitation across upper limb muscles (P=0.02). However, we observed large inter-individual variability in the strength of the effector-specific motor facilitation induced by action observation. Yet, subjects had similar types of response (strong or weak effector-specific effects) when watching proximal or distal movements indicating that the facilitation pattern was highly consistent within subjects (r=0.83-0.88, P<0.001). This suggests that some individuals are better than other at precisely mapping the observed movements on their motor repertoire and that this type of response holds for various types of everyday actions.
  • PublicationAccès libre
    Modulation of the response to a somatosensory stimulation of the hand during the observation of manual actions
    (Springer, 2010-11-03) Hétu, Sébastien; Rodrigues, Erika C.; Jackson, Philip L.; Mercier, Catherine; Voisin, Julien; Vargas, Claudia D.; Malouin, Francine.; Chapman, C. Elaine
    Observation of hand movements has been repeatedly demonstrated to increase the excitability of the motor cortical representation of the hand. Little attention, however, has been devoted to its effect on somatosensory processing. Movement execution is well known to decrease somatosensory cortical excitability, a phenomenon termed ‘gating’. As executed and observed actions share common cortical representations, we hypothesized that action observation (hand movements) should also modulate the cortical response to sensory stimulation of the hand. Seventeen healthy subjects participated in these experiments in which electroencephalographic (EEG) recordings of the somatosensory steady-state response (SSSR) were obtained. The SSSR provides a continuous measure of somatosensory processing. Recordings were made during a baseline condition and five observation conditions in which videos showed either a: (1) hand action; (2) passive stimulation of a hand; (3) static hand; (4) foot action; or (5) static object. The method employed consisted of applying a continuous 25 Hz vibratory stimulation to the index finger during the six conditions and measuring potential gating effects in the SSSR within the 25 Hz band (corresponding to the stimulation frequency). A significant effect of condition was found over the contralateral parietal cortex. Observation of hand actions resulted in a significant gating effect when compared to baseline (average gating of 22%). Observation of passive touch of the hand also gated the response (17% decrease). In conclusion, the results show that viewing a hand performing an action or being touched interferes with the processing of somatosensory information arising from the hand.
  • PublicationRestreint
    Stimulating the brain to study social interactions and empathy
    (Elsevier, 2012-03-24) Hétu, Sébastien; Jackson, Philip L.; Taschereau-Dumouchel, Vincent
    Empathy is a multi-dimensional concept allowing humans to understand the emotions of others and respond adaptively from a social perspective. This mental process, essential to social interactions, has attracted the attention of many scholars from different fields of study but the blooming interest for empathy in cognitive neurosciences has rekindled this interest. This paper reviews the growing literature stemming from studies using brain stimulation techniques that have investigated directly or indirectly the different components of empathy, including resonance, self-other discrimination, and mentalizing. Some studies have also ventured toward the modulation of this complex process and toward the investigation of different components in populations that show reduced empathic skills. We argue that brain stimulation techniques have the potential to make a unique contribution to the field of empathy research with their exclusive capacity, compared to other brain imaging techniques, to modulate the neural systems involved in the distinct components of this process. Provided the development of innovative ecological paradigms that will put people in actual social interactions as well as comprehensive and adaptive models that can integrate research from different domains, the ultimate goal of this research domain is to devise protocols that can modulate empathy in people with developmental, neurological and psychiatric disorders.
  • PublicationAccès libre
    Modulation of brain activity during action observation : influence of perspective, transitivity and meaningfulness
    (Public Library of Science, 2011-09-12) Eugène, Fanny; Hétu, Sébastien; Jackson, Philip L.; Mercier, Catherine; Michon, Pierre-Emmanuel
    The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process.
  • PublicationRestreint
    The neural network of motor imagery : an ALE meta-analysis
    (Elsevier, 2013-06-01) Eugène, Fanny; Hétu, Sébastien; Jackson, Philip L.; Saimpont, Arnaud; Coll, Michel-Pierre; Grégoire, Mathieu; Michon, Pierre-Emmanuel
    Motor imagery (MI) or the mental simulation of action is now increasingly being studied using neuroimaging techniques such as positron emission tomography and functional magnetic resonance imaging. The booming interest in capturing the neural underpinning of MI has provided a large amount of data which until now have never been quantitatively summarized. The aim of this activation likelihood estimation (ALE) meta-analysis was to provide a map of the brain structures involved in MI. Combining the data from 75 papers revealed that MI consistently recruits a large fronto-parietal network in addition to subcortical and cerebellar regions. Although the primary motor cortex was not shown to be consistently activated, the MI network includes several regions which are known to play a role during actual motor execution. The body part involved in the movements, the modality of MI and the nature of the MI tasks used all seem to influence the consistency of activation within the general MI network. In addition to providing the first quantitative cortical map of MI, we highlight methodological issues that should be addressed in future research.