Dear SPMers
Need helps regarding flexible factorial. One groups of subjects, two sessions
S1,S2, in each session two conditions C1 C2.
So..
for subject variance - equal independent- yes
factor A (S1,S2) - varience - equal independent- yes
factor B (C1,C2) - varience -equal independent -no
is this correct?
Thanks in advance
________________________________
From: Haris Styliadis <[log in to unmask]>
To: [log in to unmask]
Sent: Tue, March 8, 2011 7:54:16 AM
Subject: [SPM] Beamformers / 2nd level analysis SPM / SnPM
Dear SPMers,
I have performed a beamformer analysis (SAM) for an MEG study. Our experimental
design has two independent variables that have 2 levels(high-low). So I want to
do a factorial 2x2 design. Originally, I aimed to use SnPM but I found the
plugins offered not enough for a 2x2 factorial design. Maybe it is due to lack
of understanding SnPM's potential in such a design. So I used the 2nd level
statistics in SPM and created a factorial design with two variables as factors.
There it was possible to set the levels of these factors. Finally, I got the
main effects for the two variables.
I have the following questions
1. I did not find studies on MEG using 2nd level analysis. Instead I found MEG
studies using SnPM. Does anyone know whether it is methodologically correct to
perform 2nd level analysis in in SPM for SAM images. Any papers?
2. SnPM is offered as an alternative to SPM. How do they correlate? Although I
could not perform a factorial design, should I expect same results for a one
sample test, or a paired t test implemented in both SnPM and SPM?
Any answer is kindly appreciated
Haris
