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Dear Steve, Please forgive my lack of understanding on this subject, but how will Featquery know that i have modeled the rest period, and how will it know which EV corresponds to the rest trials? If i use the %signal change in Featquery, then the baseline will be the time average of filtered_func_data, which will include all the conditions that i do not want to model. thank you very much, paymon On 12/7/2007 5:22 AM, Steve Smith wrote: > Hi, > > You can just use Featquery to get the % signal change as it will take > care of all of these issues for you. > > Cheers. > > > > On 5 Dec 2007, at 17:47, Paymon Hosseini wrote: > >> Hello, >> >> I have an event related study that has 6 experimental conditions a >> lot of control conditions. For analyzing it, i just modeled the 6 >> experimental conditions and the rest period (i.e fixation) and >> ignored the control conditions (for now). >> >> My question is about calculating %signal change for the 6 >> experimental copes (each cope is one experimental condition minus >> fixation). Specifically, i am wondering how i should calculate the >> baseline to get the %signal change relative to fixation. I suspect >> that I cannot use filtered_func_data as baseline, because it includes >> all the control conditions that i have not modeled. A possible >> solution may be to concatenate all the fixation periods of a subject >> into one volume, and then divide the copes by this new volume and >> then multiply by 100 to get the %signal change. Is this correct? >> >> thank you very much for any help, >> paymon > > > --------------------------------------------------------------------------- > > 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 > --------------------------------------------------------------------------- >