Biology subjects

Gauthier, B.

Publications and source records attributed to Gauthier, B..

7 recordsLinked to original sources

bioRxiv2025

Uncovering executive function profiles within interindividual variability: A data driven clustering exploration of design fluency in school-aged children

This study applied unsupervised machine learning to performances on a design fluency task, to identify distinct executive function (EF) profiles among 113 neurotypical Canadian children (62% female, 74% White, aged 7-13). By tracking design, repetition, and strategy production every minute for five minutes, the results revealed two profiles: Profile A generated fewer designs but exhibited a more stable production pattern across time. Profile B, initially more productive, showed a steeper increase in repetition errors and a decline in design production. These findings demonstrate how EF interindividual variability in neurotypical children can be captured through naturally emerging performance patterns, highlighting the value of temporal analysis in differentiating executive functioning profiles.

neuroscience↗

bioRxiv2023

Embodiment in episodic memory through premotor-hippocampal coupling

Episodic memory (EM) allows us to remember and relieve past events and experiences, depending on cortical-hippocampal reinstatement involved during encoding. Although it has been claimed that EM is fundamental to establish a sense of self across time, this has never been shown experimentally. Here we combine immersive virtual reality and fMRI and report stronger hippocampal reinstatement for scenes encoded under preserved sense of self, reflecting later recall performance. We further link the sense of self to EM showing that hippocampal reinstatement is coupled with reinstatement in premotor cortex, a key sense of self region. We extend these findings in a severe amnesic patient (caused by bilateral hippocampal damage), whose memory and re-experiencing lacked the normal dependency on the sense of self. Premotor-hippocampal coupling in EM describes how the self at encoding is neurally reinstated during the retrieval of past episodes, enabling a sense of self across time. TeaserPremotor-hippocampal coupling reveals how the self is reinstated when retrieving past episodes.

neuroscience↗

bioRxiv2023

Changes in spatial self-consciousness elicit grid cell-like representation in entorhinal cortex

Grid cells in entorhinal cortex (EC) encode an individuals location in space and rely on environmental cues and multisensory bodily cues. Body-derived signals are also primary signals for the sense of self as the continuous application of visuo-tactile bodily stimuli elicits illusory drifts in perceived self-location. It is unknown whether illusory changes in self-location are sufficient to elicit grid cell like representation (GCLR) in EC and how this compares to GCLR during conventional virtual navigation. Our results show that illusory changes in perceived self-location (independent of changes in environmental navigation cues and explicit imagined navigation) evoke entorhinal GCLR, correlating in strength with the magnitude of perceived self-location, and characterized by similar grid orientation as during conventional virtual navigation. These data demonstrate that the same grid-like representation is recruited when navigating based on environmental, mainly visual cues, or when experiencing illusory forward drifts in self-location, driven by perceptual multisensory bodily cues.

neuroscience↗

bioRxiv2020

Sense of self impacts spatial navigation and hexadirectional coding in human entorhinal cortex

Grid cells in entorhinal cortex (EC) encode an individuals location in space and rely on environmental cues and self-motion cues derived from the individuals body. Body-derived signals are also primary signals for the sense of self and self-identification with a body. However, it is currently unknown whether self-identification impacts grid cells and spatial navigation. Integrating the online manipulation of bodily signals, to modulate self-identification, into a spatial navigation task and with an fMRI measure to detect grid cell-like representation (GCLR) in humans, we report improved spatial navigation performance and decreased GCLR in EC when participants navigated with enhanced self-identification. These changes were further associated with increased activity in posterior parietal and retrosplenial cortex. Modulating self-identification by controlling online body-derived signals during spatial navigation, these data link the sense of self to spatial navigation and to entorhinal grid cell-like activity within a distributed cortical spatial navigation system.

neuroscience↗

bioRxiv2018

Common recruitment of angular gyrus in episodic autobiographical memory and bodily self-consciousness

Parietal cortex and adjacent parts of the temporal cortex have recently been involved in bodily self-consciousness (BSC) and in episodic autobiographical memory (EAM). However, the neuroanatomical relationship between both fundamental aspects of self-related processing remains currently unexplored. Here we investigated whether regions in the inferior parietal lobule (IPL) that have been involved in BSC (self-location and first-person perspective) are also activate in studies investigating autobiographical memory. To examine this relation, we performed a meta-analytical study based on functional neuroimaging studies on EAM and SAM and compared them with BSC activations. We report an anatomical overlap bilaterally in the angular gyrus (AG), but not in other parietal or temporal lobe structures between BSC and EAM. Moreover, there was no overlap between BSC and SAM, suggesting that the bilateral AG is a key structure for the conscious re-experiencing of past life episodes (EAM) and the conscious on-line experience of being located and experiencing the world in first-person (BSC).

neuroscience↗

bioRxiv2018

Viewing one’s body during encoding boosts episodic memory

Episodic autobiographical memories (EAMs) are recollections of contextually rich and personally relevant past events. EAM has been linked to the sense of self, allowing one to mentally travel back in subjective time and re-experience past events. However, the sense of self has recently been linked to online multisensory processing and bodily self-consciousness (BSC). It is currently unknown whether EAM depends on BSC mechanisms. Here, we used a new immersive virtual reality (VR) system that maintained the perceptual richness of life episodes and fully controlled the experimental stimuli during encoding and retrieval, including the participants body. We report that the present VR setup permits to measure recognition memory for complex and embodied 3D scenes during encoding and retrieval, that recognition memory depends on delay and number of changed elements, and that viewing ones body as part of the virtual scene (as found in BSC studies) enhances delayed retrieval. This body effect was not observed when no virtual body or a moving control object was shown. These data show that embodied views improve recognition memory for 3D life-like scenes, thereby linking the sense of self, and BSC in particular, to episodic memory and the re-experiencing of specific past events in EAM.

neuroscience↗

bioRxiv2017

The psychological arrow of time and the human brain dynamics of event ordering

When navigating the real-world, the spatiotemporal sequencing of events is intrinsically bound to ones physical trajectory; when recollecting the past or imagining the future, the temporal and spatial dimension of events can be independently manipulated. Yet, the rules enabling the flexible use of spatial and temporal cognitive maps likely differ in one major way as time is directional (oriented from past-to-future) whereas space is not. Using combined magneto- and electroencephalography, we sought to capture such differences by characterizing time-resolved brain activity while participants mentally ordered memories from different mental perspectives in time (past/future) or space (west/east). We report two major neural dissociations underlying the mental ordering of events in time and in space: first, brain responses evoked by the temporal order and the temporal distance of events-to-self dissociated at early and late latencies, respectively whereas spatial order and distance of events-to-self elicited late brain responses simultaneously. Second, brain responses distinguishing self-position in time and the temporal order of events involved sources in the hippocampal formation; spatial perspective, order and distance did not. These results suggest that the neural dynamics evoked by the temporal ordering of a series of events retrieved from long-term memory, i.e. the psychological time arrow, entails dedicated cognitive processes in the hippocampal formation that are fundamentally distinct from the mapping of spatial location.

neuroscience↗