They are within-subject factors.

Our event-related design is a 2x2 factorial. There is a factor of social partner (peer or computer) and type of reply to a questions (agree or away). So there are 4 conditions nested within two factors.

Currently I am taking your previously-suggested approach and extracting the 1st level beta values from the post-hoc contrasts peer-comp.agree and peer-comp.away and then looking at the effect of agree/away at the 2nd level.

My research question primarily revolves around the peer-computer contrast, but I want to account for the other factor in the analysis because I would expect an interaction between partner and reply type.