Updating egocentric representations in human navigation

30 Mar

After two decades of extensive research, the existence of adult neurogenesis (ANg) in the dentate gyrus of the hippocampus is definitely proven.

Accumulating evidence indicates that there is a bidirectional relationship between memory and ANg: how and to which extent learning modifies new neurons connectivity, when new neurons contribute to memory and to which memory processes, how alterations of ANg by early life stress determine age-related memory decline, are extensively debated questions.

Similarly, spatial judgments about an object's location from an imagined perspective are facilitated by a corresponding body movement, even if the movement is performed in a different environment (Rieser, 1989; Rieser et al., 1994).

Spatial updating depends critically on whether the spatial representations are allocentric or egocentric.

Studies of offline consolidation during sleep are providing novel insights into the dynamics of memory storage for multiple types of memory.

Influential models suggest that spatial processing is essential for episodic memory [O'Keefe, J., & Nadel, L. Our results show that retrieval performance was significantly higher when encoding was performed in the egocentric-updated condition. Thus, spatial updating efficiency should depend on set size.We examined which model better accounts for human spatial updating by having people reconstruct the locations of varying numbers of virtual objects either from the original study position or from a changed viewing position.Animals use a variety of perceptual cues to account for self-motion, including optic flow, proprioceptive cues, and vestibular cues (Berthoz, Israel, Georges-Fran├žois, Grasso, & Tsuzuku, 1995; Israel, Bronstein, Kanayama, Faldon, & Gresty, 1996; Kirchner & Braun, 1994; Loomis et al., 1993; Ronacher & Wehner, 1995; Srinivasan, Zhang, Lehrer, & Collett, 1996).This updating process is also continuous, operating both during the outbound journey and on the return journey (Schmidt, Collett, Dillier, & Wehner, 1992).