also, if I only do one EV as search RT - 3 column specification- how can FSL know whether each RT is linked to a valid or invalid trial? I guess this is simply because the first column for the onset of the valid and invalid events matches - or should I do 2 EVS instead one for search valid RT and another for search invalid RT - but perhaps this does not make any differenceYes you definitely need separate EVs for the separate conditions.
lastly, how about the memory RTs? Can I just ignore these in the model specification. My main aim s to compare Valid>Invalid activity and this is not related to the memory RT but may only be related to the search RT---on the other hand, it is true after the search response, there followed a memory response, and perhaps this should be included in the model?
hope this is not much of a hassle;
best wishes!
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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
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