TY - JOUR T1 - Cognitive Strategies Dependent on the Hippocampus and Caudate Nucleus in Human Navigation: Variability and Change with Practice JF - The Journal of Neuroscience JO - J. Neurosci. SP - 5945 LP - 5952 DO - 10.1523/JNEUROSCI.23-13-05945.2003 VL - 23 IS - 13 AU - Giuseppe Iaria AU - Michael Petrides AU - Alain Dagher AU - Bruce Pike AU - VĂ©ronique D. Bohbot Y1 - 2003/07/02 UR - http://www.jneurosci.org/content/23/13/5945.abstract N2 - The human brain activity related to strategies for navigating in space and how it changes with practice was investigated with functional magnetic resonance imaging. Subjects used two different strategies to solve a place-learning task in a computer-generated virtual environment. One-half of the subjects used spatial landmarks to navigate in the early phase of training, and these subjects showed increased activation of the right hippocampus. The other half used a nonspatial strategy and showed, with practice, sustained increased activity within the caudate nucleus during navigation. Activation common to both groups was observed in the posterior parietal and frontal cortex. These results provide the first evidence for spontaneous variability and shift in neural mechanisms during navigation in humans. ER -