Navigation-related structural change in the hippocampi of taxi drivers

TLDR

Structural MRI scans of London taxi drivers were compared to non‑driver controls. Taxi drivers have larger posterior hippocampi and smaller anterior hippocampi than controls, with hippocampal volume correlating positively with driving time in the posterior region and negatively in the anterior, supporting the view that the posterior hippocampus expands with spatial experience and that adult human brains can undergo local structural plasticity.

Abstract

Structural MRIs of the brains of humans with extensive navigation experience, licensed London taxi drivers, were analyzed and compared with those of control subjects who did not drive taxis. The posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects. A more anterior hippocampal region was larger in control subjects than in taxi drivers. Hippocampal volume correlated with the amount of time spent as a taxi driver (positively in the posterior and negatively in the anterior hippocampus). These data are in accordance with the idea that the posterior hippocampus stores a spatial representation of the environment and can expand regionally to accommodate elaboration of this representation in people with a high dependence on navigational skills. It seems that there is a capacity for local plastic change in the structure of the healthy adult human brain in response to environmental demands.