Hello Everyone,I am analyzing repeated measures data for the first time in SPM8, and I just wanted to verify that I am doing so properly. We are scanning subjects 3 times using the same task, and are interested in what areas show differential responses as a function of time (e.g. Are responses greater at time 1 than at time 2 and 3?).In order to test this question, I am using the Second Level: Full Factorial option.
I specify one factor with three levels (time, at visit one, two, and three). Under “Independence” I select “No” because it is a within-subject design. I then specify three cells, and enter the contrast images from my first level analyses for time 1 into the Level 1 cell, the con images from time 2 into the Level 2 cell, and the con images from time 3 into the Level 3 cell.After design specification, and estimation, I create the following contrasts:In order to test what areas show a main effect of task across all 3 times, I create an F contrast:1 0 00 1 00 0 1
In order to test which areas show a significantly different response at different times, I create an F contrast:2 -1 -1-1 2 -1-1 -1 2
Am I analyzing the data correctly in order to test my question? Also, are the F contrasts I am creating appropriate for those questions? Any feedback you would be able to provide would be appreciated. Thanks in advance.Annchen Knodt~~~~~~~~~~~~Annchen KnodtGraduate StudentComputational Biology & Bioinformatics ProgramLaboratory of NeurogeneticsDuke University