> What are the maximum and minimum number of trials?
It varies widely, from 1 to 20+ trials. There were even instances where there were zero trials for that condition, but I dropped those subjects. I'm worried about the regressions being unbalanced. Is there any need to weight each regressor? Should I weight by the number of trials somehow? Or do you only need to weight regressors when there are different numbers of + vs -? e.g. +0.333*A + 0.333*B + 0.333*C - 0.5*D - 0.5*E?
Thank you!