Diffusion tensor imaging (DTI) techniques have made it possible to investigate white matter plasticity in humans. Changes in DTI measures, principally increases in fractional anisotropy (FA), have been observed following training programs as diverse as juggling, meditation, and working memory. Here, we sought to test whether three months of reasoning training could alter white matter microstructure. We recruited participants (n = 23) who were enrolled in a course to prepare for the Law School Admission Test (LSAT), a test that places strong demands on reasoning skills, as well as age- and IQ-matched controls planning to take the LSAT in the future (n = 22). DTI data were collected at two scan sessions scheduled three months apart. In trained participants but not controls, we observed decreases in radial diffusivity (RD) in white matter connecting frontal cortices, and in mean diffusivity (MD) within frontal and parietal lobe white matter. Further, participants exhibiting larger gains on the LSAT exhibited greater decreases in MD in the right internal capsule. In summary, reasoning training altered multiple measures of white matter structure in young adults. While the cellular underpinnings are unknown, these results provide evidence of experience-dependent white matter changes that may not be limited to myelination.
Keywords: cognitive training, fluid reasoning, plasticity, diffusion-weighted imaging, test preparation
Citation: Mackey AP, Whitaker KJ and Bunge SA (2012) Experience-dependent plasticity in white matter microstructure: reasoning training alters structural connectivity. Front. Neuroanat. 6:32. doi: 10.3389/fnana.2012.00032
Received: 30 March 2012; Accepted: 22 July 2012;
Published online: 22 August 2012.
Edited by:Daniel S. Margulies, Max Planck Institute, Germany
Reviewed by:Bogdan Draganski, University of Lausanne, Switzerland
Copyright © 2012 Mackey, Whitaker and Bunge. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Allyson P. Mackey, Helen Wills Neuroscience Institute, University of California at Berkeley, 132 Barker Hall MC 3190, Berkeley, California, USA. e-mail: firstname.lastname@example.org