Biology subjects

Gauthier, B.

Publications and source records attributed to Gauthier, B..

3 recordsLinked to original sources

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↗