I have a rather naïve question....

I have made some corrections in the form of adding CPs and erasing few dural inclusions into pial surface. Now after savingCPs, main vol and aux volume, if I run

recon-all -autorecon2-cp -autorecon2-pial -autorecon2-wm -autorecon3 -subjid somename

- will this give me the result I need? Or should I run the cp edits, pial edits and wm edits step by step (one at a a time)

Cheers LKP

On 08/12/2009 18:36, "Douglas N Greve" greve@nmr.mgh.harvard.edu wrote:

I think I would just optimize with one condition and then do the post-hoc sorting into 5. It should be ok if the subject is responding randomly. I don't have a tool for power, but optseq will give the variance reduction factor, which goes in the denominator of the t-test. This assumes you are testing an omnibus contrast, though. I think FSL might have something to test power.

doug

Kathrine Shepherd wrote:

...

Hello--

I'm designing an event-related task that does not have predefined conditions. instead, I plan to do some post-hoc sorting based on performance and stimuli characteristics. I expect that after sorting, I will have 5 conditions- but it could be more or less. Is it advisable to determine the stim presentation schedules in optseq as if I had already specified predefined conditions? Or is it optimal to just completely randomize the jitter without making any assumptions about the response function?

Also is there a tool available to estimate the stat power of my schedules after I've defined them?

Many thanks for your advice, -Kathrine _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

_______________________________________________________ Lena Palaniyappan Clinical Lecturer & Honorary StR | Division of Psychiatry ( University of Nottingham) South Block 'A' floor| Queens Medical Centre | Nottingham | NG7 2UH

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Hi Lena,

you should only need -autorecon2-cp -autorecon3, since -autorecon2-cp runs all the steps that the -wm and the -pial run (plus some more)

cheers Bruce On Tue, 8 Dec 2009, Lena Palaniyappan wrote:

I have a rather naïve question....

I have made some corrections in the form of adding CPs and erasing few dural inclusions into pial surface. Now after savingCPs, main vol and aux volume, if I run

recon-all -autorecon2-cp -autorecon2-pial -autorecon2-wm -autorecon3 -subjid somename

• will this give me the result I need?

Or should I run the cp edits, pial edits and wm edits step by step (one at a a time)

Cheers LKP

On 08/12/2009 18:36, "Douglas N Greve" greve@nmr.mgh.harvard.edu wrote:

...

I think I would just optimize with one condition and then do the post-hoc sorting into 5. It should be ok if the subject is responding randomly. I don't have a tool for power, but optseq will give the variance reduction factor, which goes in the denominator of the t-test. This assumes you are testing an omnibus contrast, though. I think FSL might have something to test power.

doug

Kathrine Shepherd wrote:

...

Hello--

I'm designing an event-related task that does not have predefined conditions. instead, I plan to do some post-hoc sorting based on performance and stimuli characteristics. I expect that after sorting, I will have 5 conditions- but it could be more or less. Is it advisable to determine the stim presentation schedules in optseq as if I had already specified predefined conditions? Or is it optimal to just completely randomize the jitter without making any assumptions about the response function?

Also is there a tool available to estimate the stat power of my schedules after I've defined them?

Many thanks for your advice, -Kathrine _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

---

Lena Palaniyappan Clinical Lecturer & Honorary StR | Division of Psychiatry ( University of Nottingham) South Block 'A' floor| Queens Medical Centre | Nottingham | NG7 2UH

This message has been checked for viruses but the contents of an attachment may still contain software viruses which could damage your computer system: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer