Vuarnesson, L. | bioRxiv Science

bioRxiv2025

Bodily perception links memory and self: a case study of an amnesic patient

Episodic autobiographical memory (EAM) is a building block of self-consciousness, involving recollection and subjective re-experiencing of personal past experiences. Any life episode is originally encoded by a subject within a body. This raises the possibility that memory encoding is shaped by bodily self-consciousness (BSC), a basic form of self-consciousness arising from the multisensory and sensorimotor perceptual signals from the body. Recent studies in healthy subjects showed that embodied encoding improves EAM, with the involvement of the hippocampus. However, there are only few imaging studies to date, hippocampal data are not consistent, and the role of hippocampal damage is not understood. We investigated how different BSC states during encoding, modulate later EAM retrieval, in a patient with severe amnesia caused by rare bilateral hippocampal damage. We performed three separate behavioral experiments using immersive virtual reality. The patient showed consistently more difficulties recollecting information encoded in embodied vs. disembodied states, particularly when asked to recall her perspective experienced at encoding. These results contrasted with the usual beneficial effect of BSC on EAM, and significantly differed from controls. These data provide consistent evidence that BSC impacts encoding and later reliving, and shows that the hippocampus is not just a critical structure for EAM, but also for effects of embodiment on memory. Additional fMRI data extend these findings by revealing that hippocampal-parietal connectivity mediates BSC-EAM coupling. Our findings plead for an important role of BSC in EAM, mediated by the hippocampus and its connectivity, leading to embodied memories that are experienced as belonging to the self. HighlightsO_LIWe studied a patient with memory deficits caused by bilateral hippocampal atrophy C_LIO_LIMultisensory stimulation modulated embodiment during episode encoding C_LIO_LIAcross three studies the patient showed stronger memory deficits for embodied episodes C_LIO_LIMultisensory bodily perception impacts bodily self-consciousness and episodic memory C_LIO_LIOur findings link the bodily self to episodic memory and the hippocampus C_LI

neuroscience↗

bioRxiv2024

Meditation in the third-person perspective modulates minimal self and heartbeat-evoked potentials

Experienced meditation practitioners often report altered states of their sense of self, including decentering and distancing the self from the body and ones current concerns. Altered states of the sense of self, such as disembodiment and distancing of the self from the body, have also been induced experimentally using virtual reality (VR) and linked neurally to heartbeat evoked potentials (HEPs). Whereas many studies investigated the related neural correlates of such decentering during meditation, none experimentally modulated the sense of self during meditation practice using VR nor determined the potentially associated behavioral changes of the sense of self. Here we determined HEPs and behavioral measures in 23 participants who performed a guided meditation practice in VR, either from a third-person (3PP) or first-person perspective (1PP) to modulate the sense of self. In the 3PP versus 1PP meditation condition, we report stronger sensations of detachment and disconnection, reduced salience of the perceived body boundary, and reduced self-identification with the body. HEP analysis revealed differential neural responses between conditions, characterized by a more negative HEP amplitude in the 3PP condition, associated with activation of the posterior cingulate cortex and medial prefrontal cortex. Leveraging a new VR-supported meditation platform and methods, these data link the sense of self in meditation practice to the neuroscience of the bodily self, based on subjective, behavioral, and neural measures.

neuroscience↗