 |
 |
Dear SPM, I wonder if I may mix contrasts from two studies I will clarify myself: -I have two experiments that are the same except for one difference in the emotional stimuli: Experiment1=fear, Experiment2=anger -I conduct a one way ANOVA with 2 groups (5 males of Experiment1, 5 other males of Exp2, 5 females of Exp. 1, 5 of Exp. 2). -I select the .con images of all females of fear vs neutral AND anger vs neutral for Group1 and the .con images of all males of fear vs neutral AND anger vs neutral for Group2 So, the male-group, for example, consists of participants of both Experiment1, and 2. -I put the beta-values in SPSS and conduct a t-test to test male-female differences in emotional processing. I'm interested in emotional effects and not so much fear- or anger-specific. That's why I want to pull them together. Is this a viable method to do? If so, do I need to equalize the number of subjects per experiment/sex or can I simply keep all my subjects no matter if I have for example more males than females? best wishes, Mariska