navigation is the ability to get from point A to point B in large-scale space.
Humans and animals use a variety of strategies to solve this problem. One such
strategy is landmark-based wayfinding, which is the use of fixed landmarks to
determine one’s location and orientation in the world. Functional resonance
magnetic imaging (fMRI) studies have identified a network of brain regions
involved in landmark-based wayfinding, including parahippocampal cortex,
retrosplenial cortex, and the medial temporal lobe (entorhinal cortex and hippocampus). However, the distinct computational functions
supported by each component of this network are still unknown. One approach to
this problem is to identify the representational distinctions made within each
brain region. I will discuss recent work that uses advanced neuroimaging techniques
to identify neural codes that support the coding of landmarks and locations
within a familiar campus environment.
Results from these experiments suggest that
parahippocampal and retrosplenial cortices encode information that allows
individual scenes and landmarks to be distinguished. The medial temporal lobe, on the other hand,
appears to encode a map-like representation of spatial coordinates that allows
distances between locations to be calculated.