A Functional Magnetic Resonance Imaging Investigation Into the Neural Correlates of Allocentric and Egocentric Spatial Memory Using Virtual Reality.

Abstract:
A virtual reality human analogue of the Morris Water Maze (the ARENA task) was developed to investigate the neural correlates of spatial memory using functional magnetic resonance imaging (fMRI). In an allocentric condition, the subjects were required to encode the position of a 'pole' in relation to abstract patterns depicted on an arena wall, subsequently moving to this location in a retrieval condition, but from a different starting place. In an egocentric condition, they were required to encode the position of a pole in relation to their own body, subsequently moving the position from the same starting location. Appropriate visual control tasks were used, with random arrangements of the arena patterns presented in a passive fashion for inspection. Activation was obtained in a network of neural structures relating to spatial memory functioning. In all conditions, the superior parietal region was activated, with bilateral hippocampal activation associated with allocentric encoding specifically. The study supports previous work implicating the hippocampus in allocentric spatial memory processing.