Hi. I have a problem with setting up FEAT properly. I've read the FEAT manual, and went through FSL course on the FSL website, but I can't get it to work properly with my data. I have a simple block design study, in which the first block is a simple visual fixation for 28 seconds, and the second block is a visual presentation of various words for 28 seconds, one word each 2 seconds. The session I try to analyze has 6 blocks of each condition (12 blocks altogether). I used the model setup wizard in FEAT to set up the analysis, and the results are fine, but it only gave me the results for 1 EV (word presentation). I would like to compare them with the activations from fixation blocks, so I chose full model setup, and that is where the problems started. I chose 2 EVs, square types for basic shapes. For the first EV (fixation) I set up Off to 28 sec, On to 28 sec, and Phase to 0. For the second EV (words) I set up Off to 28 sec, On to 28 sec, and Phase to 28 sec. Then, when I choose to view design I get the warning that the model is deficient, and at least one EV is close to a linear combination of the others, and I should alter the design. Why? I mean, if I understand correctly, I should set Off and On to the length of the block, and Phase value to shift my second EV so that it starts after the first EV ends. What am I doing wrong? I couldn't really find that On/Off/Phase part described in detail in the manual.
Please help.
Hank Owens
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