> is there a reason for having the TINY-parameter set the way it is, i.e. is
> the a downside of resetting it the way you have previously adviced for
> obtaining more data from the realignment? I am also running an experiment
> with very few slices and was considering to redefine TINY. Notably, when I
> do exclude about half of 3200 images in my time series to reduce the motion
> in it, I get less data (i.e. fewer voxels) surviving in the r*-images. Has
> somebody seen something like that before, how can you explain it? (I may
> provide more detailed information and images to illustrate my point.)
Images have a certain view, and the TINY parameter in the SPM code is there
so that data that is fractionally outside the FOV can be sampled. It was
initially included so that the edge slices were not lost from the data.
If one tries to sample too far outside the image, then the results will not
be particularly accurate.
Best regards,
-John
--
Dr John Ashburner.
Wellcome Department of Cognitive Neurology.
12 Queen Square, London WC1N 3BG, UK.
tel: +44 (0)20 78337491 or +44 (0)20 78373611 x4381
fax: +44 (0)20 78131420
http://www.fil.ion.ucl.ac.uk/~john
mail: [log in to unmask]
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