Ising Prior in fMRI detection

1. Ising Prior in fMRI detection • Junmo Kim • John Fisher • Eric Cosman • Wanmei Ou • Polina Golland

2. GLM / Ising Exact MAP Activity Detection in fMRI Using a GLM with an Ising Spatial Prior Eric Cosman, Jr., Wanmei Ou, John Fisher, William Wells

3. GLM / Ising… • Alternative model for noise reduction • Ising MRF prior model • In GLM / Hypothesis Test • Fast exact solution: Portius, Grieg • Result is F-statistic (threshold at)

5. GLM / Ising Results Eric Cosman, Jr., Wanmei Ou

6. GLM / Ising… • Wanmei Ou • MIT MS Project with Polina Golland • Empirical Characterization of fMRI detectors • Larry Panych data • GLM / MI • MARKOV spatial models • Exact • Approximate

7. GLM / Ising: Empirical Results • ROC analysis on realistic synthetic data • Low SNR regime: Gaussian Blur is Better • High SNR regime: Ising Prior is Better Eric Cosman, Jr., Wanmei Ou

8. GLM Combined with Ising Model • Eric Cosman et al. MICCAI 04 • Extends GLM hypothesis testing approach to include Ising Prior model on activations

9. Synthetic Comparison with Gaussian Smoothing

10. MI-Based fMRI Activation Detection • Standard Modeling Assumptions (GLM): • Activating Voxel intensities are proportional to protocol with added Gaussian Noise • MI approach: • A Voxel is declared active if it is not statistically independent of protocol • As Measured by MI • Andy Tsai

11. Kim MS: MI with Ising Prior on Activations • Demonstrate that MI is optimal test statistic for Likelihood Ratio Test of independence • Use Likelihood to facilitate combination with Ising prior model on activation • Show that estimator can be solved in polynomial time

12. Verb-Association Test Results Provided by Eric Cosman,Jr.

13. Representative Voxels Provided by Eric Cosman,Jr.

14. Bayesian Population Inference for the Multivariate Autoregressive Process IPMI 05?, PhD 05 Eric Cosman 1/19/05

15. The end