Ah yes - apologies for the confusion, my fault: in the text file
associated with the peristimulus plots, each line contains a different
original data timepoint: the first column is the "peristimulus time" (time
relative to the start of each event), the second column is the data, the
third column is the partial model fit for the contrast, the fourth column
is the full model fit and the fifth column is the reduced data for the
contrast. So yes as you go down the file you run through the timings for
each different event (of the same type). In order to get an average shape
you would need to either fit some function to the data (as the plots in
the report webpages do) or reconstruct the shape from the model and the
PEs. Hope this helps?
Cheers, Steve.
On Wed, 27 Apr 2005, HA Allen wrote:
> Thanks Steve
>
> Oh dear, I think I have misunderstood something basic somewhere. I dont
> think I really understand what is written in the output raw data text
> file underlying the peristimulus plots.
>
> My confusion comes from the entries in the first column of the 5 column
> text file. I understand this to be time, as show on the x axis of the
> plot. There are multiple entries of each time value (e.g. there are
> several rows that have e.g. 1.1 in the first column). What does this
> mean? Does each represent a separate trial/event? Or not?
>
> Thank you
>
> Harriet
>
--
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe 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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