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Dear Guillaume, Thanks for your help, it's very helpful! I know why I can't do any contrast in flexible factorial design, I thought I don't need to input a value for each column. Best regards, Chih-Hao ________________________________ 寄件者: Guillaume Flandin <[log in to unmask]> 寄件日期: 2017年1月11日 下午 10:39:50 收件者: 連 志浩 副本: [log in to unmask] 主旨: Re: [SPM] No contrast(s) in flexible factorial design Dear Chih-Hao, Thanks - glad to hear you have more subjects! With 18 subjects in group 1 and 8 in group 2, the contrast is: [1 0 0 0 0 0 0 0 ones(1,18)/18 zeros(1,8)] but you'd be better off doing a one-sample t-test with the 18 images for condition 1 of subjects of group 1. Best regards, Guillaume. On 11/01/17 14:00, 連 志浩 wrote: > Dear Guillaume, > > > Thanks for your advice! > > > I input more data to run my 2nd-level model, but the same situation > happens again. > > > I selected "Specify All" option, and input followed matrix in Factor matrix: > > [ 1 1 1 1 > 2 1 1 2 > 3 1 1 3 > 4 1 1 4 > 5 2 1 1 > 6 2 1 2 > 7 2 1 3 > 8 2 1 4 > .... > ...... > 97 25 2 1 > 98 25 2 2 > 99 25 2 3 > 100 25 2 4 > 101 26 2 1 > 102 26 2 2 > 103 26 2 3 > 104 26 2 4 ] > > In Main effects & Interaction option, I created a main effect (1) and a > interaction (2 3). > > > Did I do anything wrong? > > > Best regards. > > Chih-Hao > > > ------------------------------------------------------------------------ > *寄件者:* Guillaume Flandin <[log in to unmask]> > *寄件日期:* 2017年1月11日 下午 08:50:07 > *收件者:* 連 志浩 > *副本:* [log in to unmask] > *主旨:* Re: [SPM] No contrast(s) in flexible factorial design > > Dear Chih-Hao, > > This is to be expected for a model that includes subject effects. The > corresponding estimable contrast is [1 0 0 0 0 0 1/3 1/3 1/3 0 0 0] but > you are essentially trying to do a one-sample t-test with three subjects > so you should acquire data from more subjects before running a second > level model. > > Best regards, > Guillaume. > > > On 11/01/17 06:55, 連 志浩 wrote: >> Dear experts, >> >> >> I have a problem when I tried to use flexible factorial design. >> >> >> All the bars below the design matrix are gray, and I can't do any contrast. >> >> >> GUI showed "no contrast(s)" when I open SPM contrast manager, and showed >> "!invalid contrast" when I try to input any contrast. >> >> >> It's a 2 x 4 flexible factorial design with a Group factor with 2 level >> and a Condition factor with 4 level, and I set 3 factors in my model: >> >> >> Factor 1: Subject, Independence: Yes, Variance: Equal >> >> Factor 2: Group, Independence: Yes, Variance: Unequal >> >> Factor 3: Condition, Independence: No, Variance: Equal >> >> >> I would appreciate for any help. >> >> >> Thanks for your reading. >> >> >> Best, >> >> Chih-Hao >> >> >> >> >> >> >> > > -- > Guillaume Flandin, PhD > Wellcome Trust Centre for Neuroimaging > University College London > 12 Queen Square > London WC1N 3BG -- Guillaume Flandin, PhD Wellcome Trust Centre for Neuroimaging University College London 12 Queen Square London WC1N 3BG