[Freesurfer] Power analysis

External Email - Use Caution I performed a two tailed t-test analysis using stats data and after the analysis, results were corrected for multiple comparisons using FDR. Now, I want to perform a power analysis and I have some doubts: 1. Gammavar is the variance or the standard d

Re: [Freesurfer] Power analysis

e] Mdc: [3×3 double] volres: [1 1 1] tkrvox2ras: [4×4 double] But I do not know which field corresponds to the mean for the effect size. Regards, Laura > El 11 dic 2018, a las 18:21, Laura Ferrero > escribió: > > Dear Douglas, > > I performed the statistical analy

Re: [Freesurfer] Power analysis

rested in (or do for all > vertices). > You can use fast_glm_power.m in the FSFAST toolbox to compute the power > (requires stats toolbox). > > > On 12/11/18 6:39 AM, Laura Ferrero wrote: >> External Email - Use Caution >> >> Hi, >> I want to perf

[Freesurfer] Power analysis

External Email - Use Caution Hi, I want to perform a power analysis and I read that I need 3 of 4 things: 1. Effect size (mean/std) 2. False positive rate 3. Number of subjects 4. True positive rate I also read that the effect size can be calculated using gamma.mgh and gammavar.

[Freesurfer] FDR correction

External Email - Use Caution Hi, I performed an statistical analysis comparing autism group with control group using volume/area and thickness measures. I found significant differences in some regions but they were not significant after FDR correction. The majority of p-values a

[Freesurfer] aseg.stats

Dear FS team, I would like to obtain Total Brain Volume using metrics provided in aseg.stats. I have the idea of obtaining it as a result of white matter + grey matter. WM is provided in CorticalWhiteMatter and GM could be obtained with: TotalGreyMatter - RightCerebellumCor

[Freesurfer] Multiple comparisons

Dear FS team, I was doing a statistical analysis using metrics that are provided in stats files like volume of different regions, so I am not doing a voxel based morphometry. It is necessary to correct for multiple comparisons or as I am only comparing the measures of the regions betwe

[Freesurfer] Error reading FSGD file

Dear FS team, I was trying to do an analylisis using mri_glmfit command. The analysis consists of two groups of patients and I wanted to know if there was an interaction between age and group. I wrote the following lines: mri_glmfit --table table1.txt --fsgd Descriptor.txt --C C1.txt

Re: [Freesurfer] Multicenter studies

Thank you for the information. I just want to be sure if I have understood it properly. If I had two groups and two sites, my design matrix would be like: GroupDescriptorFile 1 Class PatientsGroup1 Class PatientsGroup2 Class ControlsGroup1 Class ControlsGroup2 If I want to test for the

[Freesurfer] Multicenter studies

Dear FS team, In case I have data from different centers and I would like to do a group analysis between Patients and Controls, how different centers effects could be regressed out? Should I have to analyze if there is an interaction between center and group? I have seen examples of continu

Re: [Freesurfer] Statistical analysis

ntact Susana Carmona > susannacarm...@gmail.com > > Op 7 mei 2017 19:17 schreef "Laura Ferrero Montes" : > >> >> Dear FS team, >> >> Thank you very much for your help. Just a few more questions. >> >> I want to perform a statistical ana

[Freesurfer] Statistical analysis

Dear FS team, Thank you very much for your help. Just a few more questions. I want to perform a statistical analysis between two groups:controls and patients, using age and IQ as covariates. First I have to test if there is an interaction between group and covariate using DODS. My questions

Re: [Freesurfer] Statistical analysis

Dear FS team, Thank you very much for your help. Just a few more questions. I want to perform a statistical analysis between two groups:controls and patients, using age and IQ as covariates. First I have to test if there is an interaction between group and covariate using DODS. My questions

Re: [Freesurfer] Statistical analysis

n > it with DOSS (different offset, same slope). The "same slope" means that > the difference will be the same regardless of the value of the > covariate. You will need to make a different contrast. See > https://surfer.nmr.mgh.harvard.edu/fswiki/DodsDoss > > for more in

Re: [Freesurfer] Statistical analysis

Dear FS team, I would like to make an analysis between a Patients Group and a Control Group. This study is focused on identifying if there are differences in volume between both groups. I want to regress out the effects of gender, age and IQ. My designed matrix has the following st

[Freesurfer] Multiple comparisons

Dear FS team, I would like to correct for multiple comparisons after I run command-line GLM analysis on stats tables. I would like to make a second level analysis between a control group and an autism group. I would like to know if there is a command-line in FreeSurfer or if there i