Search

International audience; Herein we present electrophysiological evidence of extremely rapid learning of new labels in a second language (L2) for existing concepts, via computerized games. However, the effect was largely constrained by crosslinguistic grammatical gender congruency. We recorded ERPs both prior to exposure with the L2 and following a 4-day training session. Prior to exposure, no modulation of the N400 component was found as a function of the correct Match vs. Mismatch of audio presentation of words and their associated images. Post-training, a large N400 effect emerged for Mismatch compared to Match trials, but only for trials on which the L2 words shared grammatical gender in the learners' L1. Behavioral results showed that all L2 words were learned equally as well, independent of gender congruency across the L1 and the L2. The results demonstrate that crosslinguistic grammatical gender congruency influences lexical activation during the initial stages of establishing a new L2 lexicon

International audience; The way doctors deliver bad news has a significant impact on the therapeutic process. In order to facilitate doctor's training, we have developed an embodied conversational agent simulating a patient to train doctors to break bad news. In this article, we present an evaluation of the virtual reality training platform comparing the users' experience depending on the virtual environment displays: a PC desktop, a virtual reality headset, and four wall fully immersive systems. The results of the experience, including both real doctors and naive participants, reveal a significant impact of the environment display on the perception of the user (sense of presence, sense of co-presence, perception of the believability of the virtual patient), showing, moreover, the different perceptions of the participants depending on their level of expertise.

Background The aim of this pilot study is to investigate the impact of virtual reality exposure therapy (VRET) on brain metabolism and connectivity. Eighteen patients with acrophobia were assessed by an 18F-FDG PET scan sensitized by virtual exposure before treatment, and nine of them were assessed again after eight sessions of VRET. Statistical Parametric Mapping was used to study the correlations between metabolism and pretherapeutic clinical scores and to compare metabolism before and after VRET (p voxel

International audience; Much is known about how different spatial reference frames continually interact to support spatial navigation, but less explored is whether it is more crucial to process object-to-object information or egocentric heading information for effective orientation in a cluttered environment. To address this question, we evaluated the possible influence on spatial performance of an interactive aerial view of different scale (small vs. large) comprising an arrow indicating participants' egocentric heading. Results revealed that the presence of a small interactive aerial view including a visualized larger arrow facilitated the retrieval of stored spatial layout. These data are consistent with recent studies revealing the role of retrosplenial cortex in translating between different spatial reference frames, and may contribute to elucidate the continuous synchronization between the inter-object direction information in the environment with respect to egocentric current heading. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

De par sa forte prevalence, sa chronicite et son impact social, la peur des hauteurs ou acrophobie represente un domaine de recherche important. La therapie comportementale par exposition a la realite virtuelle (TERV) a demontre son efficacite clinique dans le traitement de cette pathologie. Le but de cette etude TEP etait de caracteriser le metabolisme cerebral des patients atteints d’acrophobie et d’etudier l’impact de la TERV sur ce metabolisme cerebral et les modifications associees de connectivite. Methodes Dix-huit patients atteints d’acrophobie, inclus dans l’etude CTRLSTRESS (financee par la Mission pour l’Interdisciplinarite du CNRS), ont eu une TEP au 18F-FDG cerebrale, sensibilisee par une exposition concomitante a la peur du vide par realite virtuelle, avant traitement par TERV. Parmi eux, 9 patients ont de nouveau ete testes en TEP sensibilisee par realite virtuelle apres traitement. La reponse clinique a la TERV a ete evaluee par une echelle visuelle analogique (EVA) et le test comportemental d’evitement (TCE). Des comparaisons de cartes statistiques a l’aide du logiciel SPM ont ete realisees entre les patients et 18 sujets temoins sains apparies selon l’âge et le sexe (p 178). La connectivite metabolique a ete evaluee par analyse de correlation interregionale (p 84). Resultats L’echelle EVA et le test TCE ont ete significativement ameliores chez les patients apres TERV (p = 0,02). Avant TERV, les patients atteints d’acrophobie presentaient une diminution du metabolisme des regions temporales internes bilaterales en comparaison aux sujets sains. Apres TERV, les patients presentaient une augmentation de metabolisme dans les gyri superieurs frontaux et le gyrus precentral gauche, et une augmentation de la connectivite metabolique entre ce meme gyrus precentral gauche et les regions occipitales (coefficient de correlation avant et apres traitement de respectivement 0,24, p = 0,34 et 0,73, p = 0,03). Conclusion Cette etude montre l’implication du systeme limbique chez les patients atteints d’acrophobie. Par ailleurs, l’efficacite de la TERV dans cette pathologie semble liee a une augmentation de la connectivite au sein du systeme visuo-moteur, potentielle cible pour de futurs travaux de rehabilitation chez ces patients.

A particular affordance was used as a potential candidate for behavioral assessment of physical presence in virtual environments. The subjects’ task was to walk through a virtual aperture of variable widths. In the case of presence, the subjects’ body orientation, while walking, was hypothesized to be adapted to the width of the aperture and to their own shoulder width. Results show that most subjects adapted their behavior to both their body architecture and the virtual width constraints. These subjects exhibited a behavioral transition from frontal walking to body rotation while walking through broad to narrow apertures. The same behavioral transition has already been documented in real environments (Warren and Whang in J Exp Psychol Human Percept Perform 13(3):371–383, 1987). This behavioral adjustment is thus assumed to be an objective indication of presence. Beyond these results, the present study suggests that every afforded action could be a potential tool for sensorimotor assessment of physical presence.

Virtual Reality prototyping can be used early in a design process, in order to question observers about the aesthetics of future vehicles, without the need for physical mock-ups. However, it is suspected that numerical display formats and solutions are not all equivalent, concerning the physical dimensions an observer is able to appreciate. This question is particularly acute, if one considers the transferability of conclusions reached using virtual prototyping to the real outcome of the design process.

International audience; Numerous studies highlighted the influence of a tilted visual frame on the perception of the visual vertical ('rod-and-frame effect' or RFE). Here, we investigated whether this influence can be modified in a virtual immersive environment (CAVE-like) by the structure of the visual scene and by the adjustment mode allowing visual or visuo-kinaesthetic control (V and VK mode, respectively). The way this influence might dynamically evolve throughout the adjustment was also investigated in two groups of subjects with the head unrestrained or restrained upright. RFE observed in the immersive environment was qualitatively comparable to that obtained in a real display (portable rod-and-frame test; Oltman 1968, Perceptual and Motor Skills 26 503-506). Moreover, RFE in the immersive environment appeared significantly influenced by the structure of the visual scene and by the adjustment mode: the more geometrical and meaningful 3-D features the visual scene contained, the greater the RFE. The RFE was also greater when the subjective vertical was assessed under visual control only, as compared to visuo-kinaesthetic control. Furthermore, the results showed a significant RFE increase throughout the adjustment, indicating that the influence of the visual scene upon subjective vertical might dynamically evolve over time. The latter effect was more pronounced for structured visual scenes and under visuo-kinaesthetic control. On the other hand, no difference was observed between the two groups of subjects having the head restrained or unrestrained. These results are discussed in terms of dynamic combination between coexisting reference frames for spatial orientation.

International audience; The present study aims to investigate how naturalistic actions in a highly immersive, multimodal, interactive 3D virtual reality (VR) environment may enhance word encoding by recording EEG in a pre- post-test learning paradigm. Both imaging and electrophysiological data have established motor activation during language processing, and behavioral data has shown that coupling word encoding with gestures enhances learning. However, the neural underpinnings of facilitated action language learning have yet to be elucidated. Herein, we couple EEG recording with virtual reality to examine whether “embodied learning”, or learning that occurs using specific physical movements that are coherent with the meaning of new verbs, creates linguistic representations that produce greater motor resonance (mu and beta event-related synchronization/desynchronization), due to stronger motor traces, compared to learning without accompanying specific gestures. We will also investigate whether greater motor resonance while listening to learned action verbs post-learning correlates with improved retention.; Dans la veine des théories de la cognition incarnée, cette étude est un registered report qui vise à déterminer le rôle des processus moteurs dans l’apprentissage d’une deuxième langue. Les participants encoderont des verbes d’action auditifs à l’aide d’un casque de réalité virtuelle, dans un environnement interactive, multimodal et immersif. Ils effectueront des actions spécifiques, en accord avec la signification des verbes pour manipuler un objet virtuel. Dans un design pré-/post-entraînement, l’apprentissage sera évalué avec des mesures EEG et comportementales. Nous comparerons l’effet N400 pre et post-entrainement ainsi que l’activation motrice, au travers de mesures en temps-fréquence, notamment la desynchronization dans les bandes mu (8-13Hz) et beta (13-30Hz), lié aux processus moteurs. Les résultats seront également comparés à ceux résultant d’un entrainement dans lequel les participants effectuent une action non-spécifique, le pointage. Conformément à des études comportementales montrant une facilitation de mémorisation et d’apprentissage linguistique grâce à des actions congruentes au sens des items lexicaux appris, nous nous attendons à trouver un meilleure apprentissage pour les mots appris avec des gestes congruents par rapport aux mots appris avec le pointage. Cet apprentissage sera évalué par la taille de l’effet N400 ainsi que par performance comportementale dans une tâche match-mismatch post-entrainement. Nous nous attendons également à ce que l’activation motrice post-entrainement pour ces mots-ci soit plus importante comparée à celle pour les mots appris dans la condition pointage. Si c’est le cas, ceci pourrait avoir des implications importantes pour des théories sur le traitement et l'apprentissage d'une L2.