Hello, I am stuck with two error messages in the Basic Model. 1). For the one-sample t-test, I selected one subject1_con_0001.img, but got the following error message in Matlab: SPM99: spm_spm_ui (v2.33) 16:54:13 - 22/11/2002 ======================================================================= ??? Index exceeds matrix dimensions. Error in ==> c:\spm99\spm_spm_ui.m On line 810 ==> bFI = [bL(1),bL(2:3)&~bL(4),bL(4),bL([2,3])&bL(4)]; ??? Error while evaluating uicontrol Callback. 2). For the two sample t-test, I selected subject1_con_0001.img and subject2_con_0001.img, and I entered [1 -1] for the "[2]group" But, I got the following error: SPM99: spm_spm_ui (v2.33) 16:55:13 - 22/11/2002 ======================================================================= ??? Error using ==> spm_spm_ui unestimable condition effects ??? Error while evaluating uicontrol Callback. Any idea what's going on? Any suggestion will be greatly appreciated! Yuki Chen