"For example: I have contrast images giving me the difference of condition A
against an implicitly modeled baseline for 25 subjects. Now I want to know
whether all those contrasts are above null."

Isn't that exactly what a multi-subject fixed-effect conjunction will tell you?

Jeff

----- Original Message -----
From: Claus Lamm <[log in to unmask]>
Date: Tuesday, May 8, 2007 3:02 pm
Subject: [SPM] rfx conjunction across subjects
To: [log in to unmask]

> dear all:
>
> I was wondering whether there is a simple way to do a rfx
> conjunction across
> subjects for a single contrast (i.e., not a conjunction between
> groups or
> conditions, but basically a conjunction across all the subjects in
> my sample).
>
> For example: I have contrast images giving me the difference of
> condition A
> against an implicitly modeled baseline for 25 subjects. Now I want
> to know
> whether all those contrasts are above null.
>
> I know that this can be set up using a fixed-effects model but is
> it also
> possible on the second level?
>
> Thanks in advance!
> Claus
>