Motor resonance during linguistic processing as shown by EEG in a naturalistic VR environment.

Embodied cognition studies have shown motor resonance during action language processing, indicating that linguistic representations are at least partially multimodal. However, constraints of this activation linked to linguistic and extra-linguistic context, function and timing have not yet been fully explored. Importantly, embodied cognition binds social and physical contexts to cognition, suggesting that more ecologically valid contexts will yield more valid measures of cognitive processing. Herein, we measured cortical motor activation during language processing in a fully immersive Cave automatic virtual environment (CAVE). EEG was recorded while participants engaged in a Go/No-Go task. They heard action verbs and, for Go trials, performed a corresponding action on a virtual object. ERSP (event-related spectral perturbation) was calculated during verb processing, corresponding to the pattern of power suppression (event-related desynchronization - ERD) and enhancement (event-related synchronization - ERS) relative to the reference interval. Significant ERD emerged during verb processing in both the µ (8-13 Hz) and beta band (20-30 Hz) for both Go and No-Go trials. µ ERD emerged in the 400-500 msec time window, associated with lexical-semantic processing. Greater µ ERD emerged for Go compared to No-Go trials. The present results provide compelling evidence in a naturalistic setting of how motor and linguistic processes interact.

The Neural Correlates of Embodied L2 Learning: Does Embodied L2 Verb Learning Affect Representation and Retention?

We investigated 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. While behavior data have shown that coupling word encoding with gestures congruent with word meaning enhances learning, the neural underpinnings of this effect have yet to be elucidated. We coupled EEG recording with VR to examine whether embodied learning improves learning and creates linguistic representations that produce greater motor resonance. Participants learned action verbs in an L2 in two different conditions: specific action (observing and performing congruent actions on virtual objects) and pointing (observing actions and pointing to virtual objects). Pre- and post-training participants performed a match-mismatch task as we measured EEG (variation in the N400 response as a function of match between observed actions and auditory verbs) and a passive listening task while we measured motor activation (mu [8-13 Hz] and beta band [13-30 Hz] desynchronization during auditory verb processing) during verb processing. Contrary to our expectations, post-training results revealed neither semantic nor motor effects in either group when considered independently of learning success. Behavioral results showed a great deal of variability in learning success. When considering performance, low performance learners showed no semantic effect and high performance learners exhibited an N400 effect for mismatch versus match trials post-training, independent of the type of learning. Taken as a whole, our results suggest that embodied processes can play an important role in L2 learning.

Brain metabolism and related connectivity in patients with acrophobia treated by virtual reality therapy: an 18F-FDG PET pilot study sensitized by virtual exposure.

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 < 0.005, corrected for cluster volume). Metabolic connectivity was evaluated through interregional correlation analysis. RESULTS: Before therapy, a positive correlation was found between scores on the behavioural avoidance test and left occipital metabolism (BA17-18). After VRET, patients presented increased metabolism in the left frontal superior gyri and the left precentral gyrus, which showed increased metabolic connectivity with bilateral occipital areas (BA17-18-19), concomitant with clinical recovery. CONCLUSIONS: This study highlights the exciting opportunity to use brain PET imaging to investigate metabolism during virtual exposure and reports the involvement of the visual-motor control system in the treatment of acrophobia by VRET.

Being Present In Space: The Role Of Allocentric And Egocentric Reference Frames.

The general aim of the present study was to investigate the effect of an interactive aerial view of the experienced environment during the encoding and retrieving of spatial information on the feeling of presence. Our findings showed that this real-time interactive aerial view (both small and large) during the encoding and retrieval of spatial information seems to led to a greater sense of presence. It is argued that the use of this aerial view, which provides a real-time allocentric viewpoint-dependent spatial representation, would ease the translation of a stored allocentric representation into an egocentric one, and this process, consequently, would help individuals to feel present in space.

Do not get lost in translation: The role of egocentric heading in spatial orientation.

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.

Interaction between reference frames during subjective vertical estimates in a tilted immersive virtual environment.

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.