Dear Karl,
As I do not consider myself an expert I hope somebody will correct me
if I am wrong. But to me it seems that you simply are scanning
different sessions within subject. So after every time you stop the
scanner a new session starts, which can be included in SPM as such.
Kind regards,
Simone Reinders.
King's College London
Institute of Psychiatry (IoP)
De Crespigny Park
United Kingdom
On Mon, Apr 7, 2008 at 3:32 PM, Karl Koschutnig <[log in to unmask]> wrote:
> Dear experts,
>
> We wonder whether you can give us a clue on how to handle the analysis of the following fMRI design:
>
>
> 1 block consists of (1 scan = TR = 2sec)
>
> - 2 scans: fixation
>
> - 2 scans: trial instruction
>
> - 7 scans: working on the task
>
> - Then we stop the scanner for 10 seconds to record the oral responses
>
> After each block, the next block starts with the fixation.
>
>
>
>
> There are 4 conditions and we present every condition 8 times.
>
>
>
> Because of different steady state effects we throw away the first two scans (fixation). What we are interested in is the activation related to working on the task. We think the best way is to give SPM the onset of this working task and use an event-related design.
>
> The problem is we do not know how SPM handles such scanner breaks.
>
>
>
> Thanks a lot in advance for your help.
>
>
>
> Best regards,
>
> Roland & Karl
>
>
>
> ETH Zurich
>
> Dr. Roland H. Grabner
>
> Research on Learning and Instruction
>
> Institute for Behavioral Sciences
>
> Universitaetsstrasse 6, CAB G 83.2
>
> CH-8092 Zurich, Switzerland
>
>
>
> [log in to unmask]
>
> http://www.ifvll.ethz.ch
>
>
>
> +41 44 632 50 53 phone
>
> +41 44 632 12 19 fax
>
>
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