Hi Hu, you can find a good explanation of how to set up your contrasts in the flexible factorial design here: http://www.sbirc.ed.ac.uk/cyril/download/Contrast_Weighting_Glascher_Gitelman_2008.pdf Best Cyril ________________________________ From: SPM (Statistical Parametric Mapping) <[log in to unmask]> on behalf of Hu Yinying <[log in to unmask]> Sent: 15 August 2016 14:08:30 To: [log in to unmask] Subject: [SPM] Flexible factorial design contrast Dear spm Experts, I am desperately looking for help. I'm wondering if I set Flexible factorial design contrast rightly. The experiment design is 2(group: patients, controls)*2(task: memory, perception) 1 Flexible factorial design 1) variance: subject (independence-yes, variance-equal); group (independence-yes, variance-unequal); task (independence-no, variance-equal); Specify subjects: condition- [1 1; 1 2] / [2 1; 2 2] Main effects & Interactions: Main effect, subject, 1; Main effect, group, 2£»Main effect, task, 3; Interaction, [2 3] 2) Contrast£ºF-contrast Main effect group: 1 -1 0 0 0.5 0.5 -0.5 -0.5 Main effect task: 0 0 1 -1 0.5 -0.5 0.5 -0.5 Interaction group*task: 0 0 0 0 1 -1 -1 1 G1T1: 1 0 1 0 1 0 0 0 G2T1: 0 1 1 0 0 0 1 0 G1T1-G2T1: 1 -1 0 0 1 0 -1 0 G2T1-G1T1: -1 1 0 0 -1 0 1 0 G1T1-G1T2: 0 0 1 -1 1 -1 0 0 G2T1-G2T2: 0 0 1 -1 0 0 1 -1 I have referred to the paper (Glascher & Gitelman, 2008) two groups, design 2. Am I right? Thank you for your patience. Best regards! Hu Yinying School of Psychological and Cognitive Science East China Normal University, Shanghai, China