Le 01/12/2022 de 15:00 à 16:30
The Neural Bases of Egocentric Spatial Representation for Extracorporeal and Corporeal Tasks: An fMRI Study
stéphanie Leplaideur challois (Rennes, France), Annelise Moulinet-Raillon (Rennes, France), Quentin Duché (Rennes, France), Lucie Chochina (Ploemeur, France), Karim Jamal (Rennes, France), Jean-Christophe Ferré (Rennes, France), Elise Bannier (Rennes, France), Isabelle Bonan (Rennes, France)
Objective : Humans use reference frames to elaborate the spatial representations needed for all space-oriented behaviors such as postural control, walking, or grasping. We investigated the neural bases of two egocentric tasks: the extracorporeal subjective straight-ahead task (SSA) and the corporeal subjective longitudinal body plane task (SLB) in healthy participants using functional magnetic resonance imaging (fMRI). This work was an ancillary part of a study involving stroke patients.
Material / Patients and Methods : Seventeen healthy participants underwent a 3T fMRI examination. During the SSA, participants had to divide the extracorporeal space into two equal parts. During the SLB, they had to divide their body along the midsagittal plane.
Results : Both tasks elicited a parieto-occipital network encompassing the superior and inferior parietal lobules and lateral occipital cortex, with a right hemispheric dominance. Additionally, the SLB > SSA contrast revealed activations of the left angular and premotor cortices. These areas, involved in attention and motor imagery suggest a greater complexity of corporeal processes engaging body representation.
Discussion - Conclusion : This was the first fMRI study to explore the SLB-related activity and its complementarity with the SSA. Our results pave the way for the exploration of spatial cognitive impairment in patients.
Keywords : Cognition spatiale, AVC, IRM, représentation spatiale