Dimensionality estimation for group fMRI data reduction at multiple levels

Sharon Chen; Thomas J. Ross; Keh-Shih Chuang; Elliot A. Stein; Yihong Yang; Wang Zhan

doi:10.1117/12.710046

10 May 2007 Dimensionality estimation for group fMRI data reduction at multiple levels

Sharon Chen; Thomas J. Ross; Keh-Shih Chuang; Elliot A. Stein; Yihong Yang; Wang Zhan

Author Affiliations +

Proceedings Volume 6511, Medical Imaging 2007: Physiology, Function, and Structure from Medical Images; 651116 (2007) https://doi.org/10.1117/12.710046
Event: Medical Imaging, 2007, San Diego, CA, United States

Abstract

Current techniques substantially overestimate the dimensionality of group fMRI data, and this problem worsens when principle component analysis (PCA) based data reductions are applied at multiple levels. In this paper, the mechanism of the overestimation is investigated, and a new method is developed for more reliable dimensionality estimation for group fMRI data at multiple levels. Simulation suggests that small variation of the signal components within a group is a major cause of dimensionality overestimation. To obtain an improved estimation, appropriate colored noise is added into the group fMRI data in order to blur the signal component variations. The noise parameters are estimated from the original fMRI data, and the improved dimensionality is determined by applying a first-order autoregressive (AR(1)) noise fitting technique to the PCA spectrum. The proposed method was tested on group resting-state fMRI datasets acquired from 14 normal human subjects in 5 different sessions. The PCA-based data reductions were performed at 3 levels in either "individual-session-subject" or "individual-subject-session" order. Results indicate that the proposed method significantly reduces the dimensionality overestimation for multiple level data reductions. Consistency of the estimated dimensionalities is observed with different group orders of the data reduction.

Citation Download Citation

Sharon Chen, Thomas J. Ross, Keh-Shih Chuang, Elliot A. Stein, Yihong Yang, Wang Zhan, "Dimensionality estimation for group fMRI data reduction at multiple levels", Proc. SPIE 6511, Medical Imaging 2007: Physiology, Function, and Structure from Medical Images, 651116 (10 May 2007); doi: 10.1117/12.710046; https://doi.org/10.1117/12.710046

ACCESS THE FULL ARTICLE

PERSONAL SIGN IN
Full access may be available with your subscription

Email or Username Forgot your username?

Password Forgot your password?

Show

Remember Email/Username on this computer

Remember Password

No SPIE account? Create an account
or Institutional Sign In via Shibboleth

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $14.40

Non-members: $18.00 ADD TO CART

Show All Keywords

Keywords/Phrases

Search In:

Publication Years