Navigational skills correlate with hippocampal fractional anisotropy in humans

Individuals vary widely in their ability to orient within the environment. We used diffusion tensor imaging to investigate whether this ability, as measured by navigational performance in a virtual environment, correlates with the anatomic structural properties of the hippocampus, i.e., fractional anisotropy. We found that individuals with high fractional anisotropy in the right hippocampus are (a) faster in forming a cognitive map of the environment, and (b) more efficient in using this map for the purpose of orientation, than individuals with low fractional anisotropy. These results are consistent with the role of the hippocampus in navigation, and suggest that its microstructural properties may contribute to the intersubject variability observed in spatial orientation. (C) 2008 Wiley-Liss, Inc.