title: Bootstrap Enhanced Penalized Regression for Variable Selection with Neuroimaging Data.
abstract: Recent advances in fMRI research highlight the use of multivariate methods for examining whole-brain connectivity. Complementary data-driven methods are needed for determining the subset of predictors related to individual differences. Although commonly used for this purpose, ordinary least squares (OLS) regression may not be ideal due to multi-collinearity and over-fitting issues. Penalized regression is a promising and underutilized alternative to OLS regression. In this paper, we propose a nonparametric bootstrap quantile (QNT) approach for variable selection with neuroimaging data. We use real and simulated data, as well as annotated R code, to demonstrate the benefits of our proposed method. Our results illustrate the practical potential of our proposed bootstrap QNT approach. Our real data example demonstrates how our method can be used to relate individual differences in neural network connectivity with an externalizing personality measure. Also, our simulation results reveal that the QNT method is effective under a variety of data conditions. Penalized regression yields more stable estimates and sparser models than OLS regression in situations with large numbers of highly correlated neural predictors. Our results demonstrate that penalized regression is a promising method for examining associations between neural predictors and clinically relevant traits or behaviors. These findings have important implications for the growing field of functional connectivity research, where multivariate methods produce numerous, highly correlated brain networks.
authors: Department of Psychology, University of Minnesota Minneapolis, MN, USA.
authors: Samantha V
authors: SV
authors: Abram
authors: Department of Psychology, University of MinnesotaMinneapolis, MN, USA; School of Statistics, University of MinnesotaMinneapolis, MN, USA.
authors: Nathaniel E
authors: NE
authors: Helwig
authors: Department of Psychology, Stanford University Stanford, CA, USA.
authors: Craig A
authors: CA
authors: Moodie
authors: Department of Psychology, University of Minnesota Minneapolis, MN, USA.
authors: Colin G
authors: CG
authors: DeYoung
authors: Department of Psychology, University of MinnesotaMinneapolis, MN, USA; Department of Psychiatry, University of MinnesotaMinneapolis, MN, USA.
authors: Angus W
authors: AW
authors: MacDonald
authors: Department of Psychology, University of Minnesota Minneapolis, MN, USA.
authors: Niels G
authors: NG
authors: Waller
keywords: bootstrap; fMRI; functional connectivity; independent component analysis; individual differences; penalized regression