Is there any way to safely delete contrasts in SPM5? Naively, I would just load SPM then do SPM.xCon = []; then save SPM SPM but I'm a little leary of this because (a) I'm new to SPM5, (b) there's this new stuff using matlab classes.(*) (*) One weirdness (here, SPM.mat is after estimating a second level model, but before running any second level contrasts): - If I load SPM.mat without putting SPM5 in my matlab path, I get an "unknown object class error." If I go ahead and type save SPM SPM the resulting file is much smaller. - If I have SPM5 in the matlab path, and then load SPM, I no longer get the unknown class error. But if I save SPM to SPM.mat, it's still much smaller than it was before I loaded it.