
(a) HMM loglikelihood map 


(b) Gaussian loglikelihood map 


(c) HMM likelihood ratio test map 

Figure 2: (a) HMM loglikelihood map—2state HMM model is applied to all voxels. The active voxels with obvious 2state on/off patterns will have relative high likelihood given this model; (b) Gaussian loglikelihood map—“off”state Gaussian model is applied to all voxels. The nonactive voxels with obvious 2state on/off patterns will have relative high likelihood given this model; (c) HMM likelihood ratio test map—subtraction of HMM loglikelihood map and Gaussian loglikelihood map equivalent to general likelihood ration test, and it enhances the contrast for activation map. 
