Allocentric egocentric updating spatial memories
Since Tolman, the idea that most species, including humans, posses multiple mechanisms for navigating, including one dependent on information about the position of the self relative to the environment (egocentric) and another regarding the position of other objects position relative to each other in the environment (allocentric), is generally well accepted, with some caveats we will discuss. In contrast, the exact nature of these representations, when and in what manner the two representational systems manifest and interact, and what brain areas are critical for them, particularly in humans, remains less clear. We then attempt to define a network-based model of spatial navigation addressing some of these potential short-comings. Hippocampal lesions disrupt navigation based on cognitive maps but not heading vectors. doi: 10.1038/23941 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text | Google Scholar Philbeck, J. Before we begin our discussion, it is helpful to define and clarify some of the basic assumptions and ideas we will be working with throughout. Although humans have a bias toward using visual information, the others are often processed as well, and they may all contribute (either in a combined fashion or independently) to extracting information about the environment (e.g., its shape and scale), the location of items, and our own location within it. doi: 10.1037/0278-73184.108.40.206 Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text | Google Scholar O’Keefe, J., and Dostrovsky, J. While navigating, we become familiar with the environment and acquire knowledge about it, thereby extracting information from it and storing this information in our memory so that we can recall it later for a variety of purposes.
Instead, an allocentric representation emerges from computations partially shared across numerous interacting brain regions.
The use of an allocentric representation will most often be pronounced at decisions points, and in particular, when we make judgments about the relative position of objects based on our memory of the location where they have previously been encountered.