You might want to have a look at the papers by Mechelli (UCL, Friston group)
and Visscher (WashU) both in NeuroImage; also check out Laurienti in J
Neurosci Methods, and I remember a recent application by the group of
Villringer (Hum Brain Mapping?)
as for the modeling, you have to include separate regressors for both the
state (block) and event-related responses;
also search the archives I remember there was a discussion about this a
while (long time?) ago, in particular concerning how to make regressors
orthogonal
hope this helps
Claus
************
Dr. Claus Lamm
Research Associate
Social Cognitive Neuroscience
Department of Psychology
The University of Chicago
5848 S. University Avenue, Chicago, IL 60637
Phone: (773) 702-4661 Fax: (773) 702-0886
EMail: [log in to unmask]
Web: http://scnl.org/claus.html
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On
Behalf Of yapeng WANG
Sent: Thursday, November 08, 2007 3:24 PM
To: [log in to unmask]
Subject: [SPM] how to separate state and item related brain regions
hello, spmers,
I just conducted a mixed bolcked-ER fmri research, in which I tried to
explore the neural mechanisms of task switching. My task included single
task(Bolcked condition task A or B)and mixed task block(task A/B repeat,
Task A/B Switching). So there are Blocked
single task A, B, base-line ,task A/B repeat, task A switch to Task B and
Task B switch to Task A.
Now, I try to seperate state-related(Block) and item-related (ER)brain
regions, but I don't know how to define contrasts that can be used to
separate state(sustained)-related and item (transient)related brain regions.
Can anybody offer me some suggestions on this? Thank you in advance.
Yapeng Wang
Yapeng Wang, Ph.D.
I-LABS
University of Washington in seattle
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