Nicole. Typing "1" will give you a positive correlation and typing "-1"
will give you a negative correlation.
Nelly
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
On Behalf Of Nicole David
Sent: Tuesday, September 06, 2005 9:23 AM
To: [log in to unmask]
Subject: [SPM] basic models: regression (correlation)
Hi all,
I have a question about the 2nd level basic-models
regression/correlation
option.
Say I have two conditions A & B and I want to look at A-B and covary
with
accuracy. So, I take the first level con-img for A-B and enter my
accuracy
vector. In the contrast manager, I make a "1" contrast. Am I correct to
assume that the resulting activation is in brain regions that vary with
accuracy, e.g. the better people are the more they recruit these
ragions?
Is there a direction of this correlation, postive or negative?
What if I type "-1" in the contrast manager, do I then get a negative
correlation or do I get results for B-A? I assume it is the latter...
Thanks,
Nicole
|