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Hi, well, this is truly beyond my reach. I cannot tell why your results might be insignificant. Might be due to an error in the analysis, might be due to a lack of power, or might be just because there is no effect. I would advise you to get back to your supervisor and ask for local help. When you say you have 14 people: is that a single population, or do you have two groups you want to compare adding up to a total of 14 people? And finally (excuse me for asking): are you sure you know what dual regression is doing for you? All the best, Cornelius On Thu, Jul 7, 2011 at 12:48 PM, Rosalia Dacosta Aguayo <[log in to unmask]> wrote: > > Hello Cornelius, > > I have gotten only one cluster,...is insignificant....but I only have a > sample of 14 subjects....what can I do? I have to present my work of Master > and I would like doing correlations..... > > Correlations with FSL or with SPSS? > > I am really decepcionated and lost.... > > Could you help me or give me and advice? > > Thanks. > > Rosalia. > 2011/7/7 Rosalia Dacosta Aguayo <[log in to unmask]> >> >> Hi Cornelius! >> >> Done it!! >> >> Cluster, mask of results and activation values!! only with corrp data. >> >> Thank you very much! >> >> Keep in touch, please. >> >> Rosalia. >> >> 2011/7/7 Cornelius Werner <[log in to unmask]> >>> >>> Hi, >>> >>> there might be a typo (oooo vs 0000, for example). Don't copy my exact >>> term, look inside your directory how the files are called (or get some >>> local help with someone proficient at shell commands). >>> Cheers, >>> Cornelius >>> >>> On Thu, Jul 7, 2011 at 10:51 AM, Rosalia Dacosta Aguayo >>> <[log in to unmask]> wrote: >>> > >>> > Hi Cornelius, >>> > >>> > I have a problem: >>> > >>> > report_DMNP]$ cluster -i dr_stage3_icoooo_tfce_corrp_stat1 -t 0.949 -o >>> > clustered_image_dr_stage3_ic0000_tstat1.nii.gz >>> > ** ERROR (nifti_image_read): failed to find header file for >>> > 'dr_stage3_icoooo_tfce_corrp_stat1' >>> > ** ERROR: nifti_image_open(dr_stage3_icoooo_tfce_corrp_stat1): bad >>> > header >>> > info >>> > Error: failed to open file dr_stage3_icoooo_tfce_corrp_stat1 >>> > Cannot open volume dr_stage3_icoooo_tfce_corrp_stat1 for reading! >>> > [neuropsico1@UB16-336-161116099027 report_DMNP]$ >>> > >>> > 2011/7/7 Cornelius Werner <[log in to unmask]> >>> >> >>> >> Hi, >>> >> >>> >> an uncorrected threshold of 0.01 will yield too many false-positives, >>> >> in my opinion. If none of the uncorrected differences survive >>> >> correction for multiple testing, then that's a fact. I would not try >>> >> and force the matter unnecessarily. For the underlying final >>> >> statistics, familiarize yourself with the "randomise" command. The >>> >> dual_regression script itlself is also not too complicated for someone >>> >> apt at shell scripting. >>> >> >>> >> To get the cluster statistics: >>> >> type "cluster -i dr_stage3_ic00001_corrp_tstat1 -t 0.949 -o >>> >> clustered_image_ic00001.nii.gz" >>> >> This produces an image containing only clusters significant at p<0.05 >>> >> corrected for component 2 (!) of the web page report >>> >> (ic00000=component 1, ic00001=component 2 and so on). >>> >> To get images containing only single clusters type "fslmaths >>> >> clustered_image_ic00001.nii.gz -thr 1 -uthr 1 >>> >> cluster1_image_ic00001.nii.gz" for cluster number 1, "fslmaths >>> >> clustered_image_ic00001.nii.gz -thr 2 -uthr 2 >>> >> cluster2_image_ic00001.nii.gz" and so forth. Hope that helps. >>> >> >>> >> Best wishes, >>> >> Cornelius >>> >> >>> >> On Wed, Jul 6, 2011 at 7:07 PM, Rosalia Dacosta Aguayo >>> >> <[log in to unmask]> wrote: >>> >> > Yes, Cornelius, >>> >> > But I have differences with all my networks with uncorrected data, >>> >> > and I >>> >> > would like including them to see what happens...with a threshold of >>> >> > 0.99, I >>> >> > think it's good, but I don't know if it's generally accepted in the >>> >> > literature. And, I don't know how to do this...I have been reading >>> >> > Randomise but I am just a begginer and in another language I have >>> >> > arrived to >>> >> > do dual_regression...but I need some more helping. Could you help >>> >> > me, >>> >> > please? >>> >> > >>> >> > Best regards, >>> >> > Rosala. >>> >> > 2011/7/6 Cornelius Werner <[log in to unmask]> >>> >> >> >>> >> >> If you have run an unmodified version of the script, the "corrp" >>> >> >> output IS already cluster thresholded (using TFCE) corrected for >>> >> >> multiple comparisons. That's why it is called "corrp" = corrected >>> >> >> p. >>> >> >> TFCE has the advantage that no a priory cluster forming threshold >>> >> >> needs to be specified, and it is quite sensitive. If you took the >>> >> >> notion of correcting for multiple testing really seriously, you >>> >> >> probably needed to divide your p-value by the number of components >>> >> >> and >>> >> >> the number of directional tests for each component...Therefore, >>> >> >> there >>> >> >> is no need (and probably no use) in cluster correcting the >>> >> >> uncorrected >>> >> >> data. You could apply a FDR correction, however. See the online >>> >> >> manual >>> >> >> on how to do it. On a side note: it is not expected for every map >>> >> >> to >>> >> >> behave differentially across groups. >>> >> >> >>> >> >> Cheers, >>> >> >> Cornelius >>> >> >> >>> >> >> On Wed, Jul 6, 2011 at 6:30 PM, Rosalia Dacosta Aguayo >>> >> >> <[log in to unmask]> wrote: >>> >> >> > Hi, >>> >> >> > I have done dual_regression and I have seen with fslview >>> >> >> > dr_stage3 >>> >> >> > corrp_stat1 and 2 and pstat1 and 2. >>> >> >> > I have seen that with a threshold of 0.95 (corrp_stat1 and 2) >>> >> >> > with >>> >> >> > only >>> >> >> > 14 >>> >> >> > subjects I have ssen activation in only two or three networks. >>> >> >> > But, >>> >> >> > with >>> >> >> > pstats1 and 2, with a threshold of 0.99, all my components show >>> >> >> > activation >>> >> >> > in the different networks. Now, I have to do the clustering, but >>> >> >> > I >>> >> >> > don't >>> >> >> > know how to do it...someone could help me, please? >>> >> >> > Thank you. >>> >> >> > Rosalia. >>> >> >> >>> >> >> >>> >> >> >>> >> >> -- >>> >> >> Dr. med. Cornelius J. Werner >>> >> >> Department of Neurology >>> >> >> RWTH Aachen University >>> >> >> Pauwelsstr. 30 >>> >> >> 52074 Aachen >>> >> >> Germany >>> >> > >>> >> > >>> >> >>> >> >>> >> >>> >> -- >>> >> Dr. med. Cornelius J. Werner >>> >> Department of Neurology >>> >> RWTH Aachen University >>> >> Pauwelsstr. 30 >>> >> 52074 Aachen >>> >> Germany >>> > >>> > >>> >>> >>> >>> -- >>> Dr. med. Cornelius J. Werner >>> Department of Neurology >>> RWTH Aachen University >>> Pauwelsstr. 30 >>> 52074 Aachen >>> Germany >> > > -- Dr. med. Cornelius J. Werner Department of Neurology RWTH Aachen University Pauwelsstr. 30 52074 Aachen Germany