Dear SPM members,
I am running an event-related fmri data analysis and have some questions on the modeling of using Fourier basis set.
Fisrt, I have no idea about to what extent my event-related responses will fit the HRF, thus i get the suggetion that the Fourier basis set will be better to detect this kind of signal reponse. Is this right? And, what order number should i use in the model?
Second, when I used the default order of 4, I found that there were 9 columns for each condition in my matrix. I wonder what is the meaning of each column? And, how can i define the contrast (for example, i have two conditions A & B, thus 19 columns in the matrix, including one white baseline, i want to examine brain activations related to A, B, and A-B)? Should i use t-contrast or f-contrast?
thanks and best
----------------------------
Hengyi Rao, Ph.D.
[log in to unmask]
Department of Neurology
University of Pennsylvania
3 W Gates
3400 Spruce Street
Philadelphia, PA, 19104
----------------------------
|