Back To Index Previous Article Next Article Full Text Supplement


Statistica Sinica 18(2008), 1553-1568





HYBRID PERMUTATION TEST WITH APPLICATION

TO SURFACE SHAPE ANALYSIS


Chunxiao Zhou and Yongmei Michelle Wang


University of Illinois at Urbana-Champaign
Abstract: This paper presents a new statistical surface analysis framework that aims to accurately and efficiently localize regionally specific shape changes between groups of 3D surfaces. With unknown distribution and small sample size of the data, existing shape morphometry analysis involves testing thousands of hypotheses for statistically significant effects through permutation. In this work, we develop a novel hybrid permutation test approach to improve the system's efficiency by approximating the permutation distribution of the test statistic with a Pearson distribution series that involves the calculation of the first four moments of the permutation distribution. We propose to derive these moments theoretically and analytically without any permutation. Detailed derivations and experimental results using two different test statistics are demonstrated using simulated data and brain data for shape morphometry analysis. Furthermore, an adaptive procedure is utilized to control the False Discovery Rate (FDR) for increased power of finding significance.



Key words and phrases: FDR, MRI, Pearson distribution, permutation test, ROI, shape analysis, surface morphometry.

Back To Index Previous Article Next Article Full Text Supplement