Hi,
I know the issue of having empty EVs for run subjects run has been addressed
but still cannot figure out my case
Each subject received a single fMRI run and the trials are classified in 3 EVs
as function of the subjective visibility of the visual target (1- not seen, 2 maybe, 3- sure).
I want to do a linear contrast eg. -1 0 1 across the EVs.
The thing is that some subjects dont have one of the EVs. Given there is a single fMRI run
this is a bit worrying...
Would still be OK to use the empty EVs ? would the higher level analyses with the linear contrast
still work in FEAT?
I was thinking or re-labelling my EVs in 2 levels rather than 3 but this is not ideal....
any other sugestions please? would perhaps randomise offer a better approach?
Thanks for any input,
regards, David
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