Seeing your own body in Virtual Reality impacts episodic memory
© B. Gauthier / 2020 EPFL
How does the experience of seeing our own body impact our memory? In order to address this question Baptiste Gauthier and colleagues used resting-state fMRI to measure activity changes related to the experience of one’s own body as compared to seeing no body, using immersive virtual reality. They found body view-induced increased connectivity within the right medial temporal lobe (MTL) and MTL-neocortical connectivity changes correlating with the subjective experience of remembering, providing neural evidence linking the bodily self and episodic memory.
Abstract Episodic memory (EM) is classically conceived as a memory for events, localized in space and time, and characterized by autonoetic consciousness (ANC) allowing to mentally travel back in time and subjectively relive an event. Building on recent evidence that the first-person visual co-perception of one's own body during encoding impacts EM, we used a scene recognition task in immersive virtual reality (VR) and measured how first-person body view would modulate peri-encoding resting-state fMRI, EM performance, and ANC. Specifically, we investigated the impact of body view on post-encoding functional connectivity in an a priori network of regions related either to EM or multisensory bodily processing and used these regions in a seed-to-whole brain analysis. Post-encoding connectivity between the right hippocampus (rHC) and right parahippocampus (rPHC) was enhanced when participants encoded scenes while seeing their body. Moreover, the strength of connectivity between the rHC, rPHC and the neocortex displayed two main patterns with respect to body view. The connectivity with a sensorimotor fronto-parietal network, comprising primary somatosensory and primary motor cortices, correlated with ANC after - but not before - encoding, depending on body view. The opposite change of connectivity was found between rHC, rPHC and the medial parietal cortex (from being correlated with ANC before encoding to an absence of correlation after encoding), but irrespective of body view. Linking immersive VR and fMRI for the study of EM and ANC, these findings suggest that seeing one's own body during encoding impacts the brain activity related to EM formation by modulating the connectivity between the right hippocampal formation and the neocortical regions involved in the processing of multisensory bodily signals and self-consciousness.
- Gauthier, B., Bréchet, L., Lance, F., Mange, R., Herbelin, B., Faivre, N., Bolton, T. A. W., Ville, D. V. D., & Blanke, O. (2020). First-person body view modulates the neural substrates of episodic memory and autonoetic consciousness : A functional connectivity study. NeuroImage, 223, 117370. https://doi.org/10.1016/j.neuroimage.2020.117370
This work was supported by the Bertarelli Foundation, the Human Neuroscience Platform, Fondation Campus Biotech Geneva (FCBG), Geneva, Switzerland, the University of Geneva (UniGe), the Hôpitaux Universitaires de Genève (HUG) and by the Institute of Translational Molecular Imaging (ITMI), and by JST ERATO Grant Number JPMJER1801, Japan.