Hi Kristine,

yes, this is true whenever there are changes to the motion correction (creation of rawavg). So far we have used FLIRT and I am not sure how often we propagated any FLIRT updates into the stream. Now using the new robust motion correction tools for the motion correction step will give more accurate averages.

Since these tools are still being improved, it is very likely that in the motion correction will behave differently even in the next few releases.

Now you have three options: 1. redo everything, including edits (I'd recommend this, if you only have a few subjects, only little edits). The edits should not move far, as we resample the rawavg at the 001.mgz space so coordinates should generally not change. 2. keep the old rawavg and old edits and reprocess skipping the motion correction. This can be recommended if you do not add new data to the study as mixing the two motion correction methods within a study is a bad idea. 3. use the flag -flirt-motioncor which reverts back to the old motion correction.

Hope that helps, Martin

On Tue, 2010-09-07 at 12:56 -0400, Bruce Fischl wrote:

Hi Kristine,

you're probably right, but maybe Martin and/or Doug can chime in.

Bruce

On Tue, 7 Sep 2010 k.b.walhovd@psykologi.uio.no wrote:

...

Hi,

I see there's a new motion correction procedure in fs5, meaning that the rawavg is created differently.

When reprocessing data, should we then do everything over, including remaking the rawavg and all edits? I'm asking esp. w/ regards to edits - can they possibly be slightly wrong if kept? And with regard to reprocessing data that have been run w/ the previous versions together with data that have not been previously processed- will such a mix be problematic?

I'd highly appreciate your recommendations!

Best,

Kristine

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