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

Grid cells in the entorhinal cortex, which encode location in space using environmental and bodily cues, also respond to illusory shifts in self-location caused by multisensory bodily stimulation, even without actual movement or visual navigation. In this fMRI study, participants experienced controlled illusory forward drifts in self-location through visuo-tactile stimulation while their visual viewpoint remained fixed. The entorhinal cortex showed grid cell-like representations that correlated with the magnitude of the perceived self-location and had the same grid orientation as during conventional virtual navigation. This indicates that the same neural representation is recruited for navigation based on environmental cues and for self-location changes driven by bodily signals.

Study at a glance

Abstract

Grid cells in the entorhinal cortex (EC) encode an individual's location in space, integrating both environmental and multisensory bodily cues. Notably, body-derived signals are also primary signals for the sense of self. While studies have demonstrated that continuous application of visuo-tactile bodily stimuli can induce perceptual shifts in self-location, it remains unexplored whether these illusory changes suffice to trigger grid cell-like representation (GCLR) within the EC, and how this compares to GCLR during conventional virtual navigation. To address this, we systematically induced illusory drifts in self-location toward controlled directions using visuo-tactile bodily stimulation, while maintaining the subjects' visual viewpoint fixed (absent conventional virtual navigation). Subsequently, we evaluated the corresponding GCLR in the EC through functional MRI analysis. Our results reveal that illusory changes in perceived self-location (independent of changes in environmental navigation cues) can indeed evoke entorhinal GCLR, correlating in strength with the magnitude of perceived self-location, and characterized by similar grid orientation as during conventional virtual navigation in the same virtual room. 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.