When single subjects are given multiple runs of the same trial, I understand the recommendation
from FMRIB to be that the runs should not be concatenated directly unless there was extremely
little motion. Instead, the recommendation is to bring the repeated trials of the individual to a
second and third level analysis using FLAME.
My question is: wouldn't doing so imply a mixed (random) effects treatment of the repeated trials,
which should be a fixed effect? Would it not make sense to co-register the COPEs and VARCOPEs,
average the COPE's and take the r.m.s. average of the VARCOPES (or some other transformation on
the variances) to come up with summary stats on these single subjects to propagate to the next
level analysis? This would have the added benefit of much reduced computation time.