LLN, le 18/04/08
If your scanner stopped, it is usually not recommended to compare
directly 2 conditions coming from the 2 sessions. It would be better
if you could compare them "indirectly". Something like: (1A minus
something_from_session1)minus(2A minus something_from_session2).
Hope this helps,
>>Lets say I have 2 scanning sessions. In both sessions there are
>>conditions A and B resulting in: 1A 1B 2A 2B
>>Between the scanning sessions I need to give the participants a
>>different set of instructions for how to act during the session e.g.
>>Instruction A, start scanning 1A 1B, stop scanning, Instruction B,
>>start scanning 2A 2B.
>>My question is: when I set up my GLM model can I have 4 columns (1A
>>1B 2A 2B) and compare 1A to 2A (and vice versa)?
>That's what I would do - and this is fine
>Obviously there is a 'session effect' which is kind of random on the
>signal and if any special direction from 1 --> 2 by counterbalancing
>this should do the trick
>Maybe (I'm not) sure normalization within/between sessions could
>also influence the result but I can't tell in which direction ...
>maybe somebody out there has an idea?
>Hope this helps
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