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Journal of Aging Research
Volume 2012 (2012), Article ID 939285, 11 pages
http://dx.doi.org/10.1155/2012/939285
Research Article

Caudate Nucleus Volume Mediates the Link between Cardiorespiratory Fitness and Cognitive Flexibility in Older Adults

1Department of Psychology, Carnegie Mellon University, Pittsburgh, PA 15213, USA
2Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA
3Department of Psychology, University of Pittsburgh, 3107 Sennott Square, 210 South Bouquet Street, Pittsburgh, PA 15260, USA
4Department of Psychology, University of Iowa, Iowa city, IA 52242, USA
5Department of Psychology, The Ohio State University City, Columbus, OH 43210, USA
6Department of Psychology, University of Illinois, Champaign-Urbana at Champaign, IL 61820, USA
7Beckman Institute for Advanced Science and Technology, University of Illinois at Champaign-Urbana, Champaign, IL, USA
8Department of Psychology, The University of Texas at Dallas, Dallas, TX 75080, USA
9Department of Kinesiology and Community Health, University of Illinois, Champaign-Urbana at Champaign, IL 61820, USA

Received 31 March 2012; Accepted 3 June 2012

Academic Editor: Denis Gerstorf

Copyright © 2012 Timothy D. Verstynen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The basal ganglia play a central role in regulating the response selection abilities that are critical for mental flexibility. In neocortical areas, higher cardiorespiratory fitness levels are associated with increased gray matter volume, and these volumetric differences mediate enhanced cognitive performance in a variety of tasks. Here we examine whether cardiorespiratory fitness correlates with the volume of the subcortical nuclei that make up the basal ganglia and whether this relationship predicts cognitive flexibility in older adults. Structural MRI was used to determine the volume of the basal ganglia nuclei in a group of older, neurologically healthy individuals (mean age 66 years, N=179). Measures of cardiorespiratory fitness (VO2max), cognitive flexibility (task switching), and attentional control (flanker task) were also collected. Higher fitness levels were correlated with higher accuracy rates in the Task Switching paradigm. In addition, the volume of the caudate nucleus, putamen, and globus pallidus positively correlated with Task Switching accuracy. Nested regression modeling revealed that caudate nucleus volume was a significant mediator of the relationship between cardiorespiratory fitness, and task switching performance. These findings indicate that higher cardiorespiratory fitness predicts better cognitive flexibility in older adults through greater grey matter volume in the dorsal striatum.