Dear David:
Thanks for your answers and Question 3 is now solved. As for Questions
1 and 2, I think there is some misunderstanding and I apologize for
that. These two questions refer to the FEAT output rather than the
MELODIC output. I need you to confirm if the data points of the
time-series plot in the FEAT output are beta weights, z or others?
Thanks again.
Best,
Wei-Ta
2013/2/1 David V. Smith <[log in to unmask]>:
> Hi Wei-Ta,
>
> I'm not sure how you have output from FEAT if you're using MELODIC ICA and
> dual regression. In any case, the report.html probably won't be of much use
> to you since you're doing dual regression, but here's some feedback on your
> questions:
> 1) They're not beta weights. Assuming you're using concat, the displayed
> time course is an approximation of all inputted datasets (see
> http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/MELODIC for a better description).
> 2) Sorry, I'm not sure about this one, but perhaps it is explained in the
> documentation or prior posts on the listserv.
> 3) Those numbers reflect the center of gravity of each cluster in MNI space
> (usually only done with FEAT output, so are you sure you're using ICA and
> dual regression?). The max COPE and max z-stat do not have to be the same
> voxel -- e.g., a high COPE value with a high variance will have a low
> z-stat.
>
> Hope that helps.
>
> Cheers,
> David
>
>
> On Feb 1, 2013, at 4:54 AM, ³¯³¹F wrote:
>
> Dear David:
>
> Yes. I am using dual regression. Sorry I did not mention that previously.
>
> Do you have any clue or references for my questions? Thanks in advance.
>
> Best,
>
> Wei-Ta
>
>
>
> 2013/2/1 David V. Smith <[log in to unmask]>:
>
> If you're interested in group differences in networks estimated with ICA,
>
> then you should use dual regression:
>
> http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/DualRegression
>
>
> David
>
>
> On Feb 1, 2013, at 12:37 AM, ³¯³¹F wrote:
>
>
> Hi FSL experts:
>
>
> I am analyzing resting-state functional connectivity data using ICA
>
> and cluster-based thresholding. Two groups are studied (patients
>
> [n=18] vs. controls [n=23]). When I check the higher level FEAT
>
> results (report.html), there are time-series plots (of the peak Z
>
> voxel) for each contrast (control group, patient group,
>
> control-patient, patient-control, 4 contrast in total for my study).
>
>
> My questions are:
>
> 1. What are the y values of the Time-series plots? Are they beta
>
> weights or z values? As I know, the x value (0-50) is the numbers of
>
> the subject.
>
> 2. When I click the plots for each contrast, two plots of full-model
>
> fit will pop up. Then I click the "raw data", a four-colume text file
>
> will pop up. In this text file, I think the values of the most left
>
> colume are the y values of the time-series plot (as question 1).
>
> Columes 2 and 3 seems to be contrast-specific values. But I have no
>
> idea what are the values in the most right columes.
>
> 3. When I click on a cluster of activation on the color rendered FEAT
>
> stats, a webpage of "cluster List" table will appear. I would like to
>
> ask what are the values of Z COG X (mm), Z COG Y and Z COG Z? Another
>
> question is: why the Z MAX coordinate and COPE MAX coordinate are
>
> different?
>
>
> Thanks!!
>
>
> Best,
>
>
> Wei-Ta Chen, MD, PhD
>
> Taipei Veterans General Hospital
>
>
>
> --------------------------------------------
>
> David V. Smith, Ph.D.
>
> Postdoctoral Fellow, Delgado Lab
>
> Department of Psychology
>
> Rutgers University
>
> Newark, NJ 07102
>
> --------------------------------------------
>
>
>
> --------------------------------------------
> David V. Smith, Ph.D.
> Postdoctoral Fellow, Delgado Lab
> Department of Psychology
> Rutgers University
> Newark, NJ 07102
> --------------------------------------------
>
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