Hi - I would use the first approach - that's what it's for!
Cheers.



On 17 Feb 2011, at 17:40, Andrej Schoeke wrote:

Hi all,

first, thank you for such a great mailing list. I worked with a lot of software and never had such a helpful mailing list. :)

I ran into a problem and I found two possible solution and I am not sure which one would be the best.
My experiment consists of six blocks with a consequent memory test per session per participant. I want to run an analysis that looks for activation for correct remembered pictures and incorrect/not remembered pictures. I also want to run some contrast on these two EVs.
Now, it happens of course, that for some blocks, people have no correct or incorrect answers. So, the corresponding timing file would be empty, crashes would occur and I would be very sad. Especially, as I want to combine the session blocks in a higher level and I need the copes to be there for every block.

I searched the mailing list and found two ways of dealing with it.
First, I could replace the EV with the empty timing file with an empty EV. (Message-id: <[log in to unmask]>)
Another way might be to replace the empty timing file with a de-weighted entry such as 0 0 0. (<[log in to unmask]>)
Which of these approaches would be "cleaner"? Are there other ways to deal with this issue?

Thank you so much for your help,
Andrej



---------------------------------------------------------------------------
Stephen M. Smith, Professor of Biomedical Engineering
Associate Director,  Oxford University FMRIB Centre

FMRIB, JR Hospital, Headington, Oxford  OX3 9DU, UK
+44 (0) 1865 222726  (fax 222717)
[log in to unmask]    http://www.fmrib.ox.ac.uk/~steve
---------------------------------------------------------------------------