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International Journal of Biomedical Imaging
Volume 2012 (2012), Article ID 574971, 14 pages
http://dx.doi.org/10.1155/2012/574971
Research Article

Extending Local Canonical Correlation Analysis to Handle General Linear Contrasts for fMRI Data

1Department of Physics, University of Texas at Arlington, Arlington, TX 76019, USA
2Department of Radiology, School of Medicine, University of Colorado Denver, Aurora, CO 80045, USA
3Departments of Biostatistics and Psychology, UCLA, Los Angeles, CA 90095, USA
4Department of Psychology and Neuroscience, University of Colorado at Boulder, Boulder, CO 80309, USA

Received 1 July 2011; Revised 25 September 2011; Accepted 28 September 2011

Academic Editor: Weihong Guo

Copyright © 2012 Mingwu Jin 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

Local canonical correlation analysis (CCA) is a multivariate method that has been proposed to more accurately determine activation patterns in fMRI data. In its conventional formulation, CCA has several drawbacks that limit its usefulness in fMRI. A major drawback is that, unlike the general linear model (GLM), a test of general linear contrasts of the temporal regressors has not been incorporated into the CCA formalism. To overcome this drawback, a novel directional test statistic was derived using the equivalence of multivariate multiple regression (MVMR) and CCA. This extension will allow CCA to be used for inference of general linear contrasts in more complicated fMRI designs without reparameterization of the design matrix and without reestimating the CCA solutions for each particular contrast of interest. With the proper constraints on the spatial coefficients of CCA, this test statistic can yield a more powerful test on the inference of evoked brain regional activations from noisy fMRI data than the conventional t-test in the GLM. The quantitative results from simulated and pseudoreal data and activation maps from fMRI data were used to demonstrate the advantage of this novel test statistic.