Re: [HCP-Users] How to threshold the task data?

It was created by submitting the results for all 440 subjects into a "Level 3" group-level analysis.  Basically the same as one would be doing in a group analysis in SPM or FSL, but applied to the CIFTI data.  If you aren't familiar with this process, I'd suggest that you review the FSL FEA

Re: [HCP-Users] How to threshold the task data?

Dear Michael, Thank you for the explaination. The maximum value is around 30 in one averaged motor task map across 440 subjects, but if 30 over 440 is around 0.07, then this value is a bit of low as the individual-level. How was the averaged activation map created? average across individual activa

Re: [HCP-Users] Documentation for 100 and 400+-subject group-average datasets

Hi Estrid, The documentation on the processing for the group average fMRI data is in the Reference Manual , on pages 78-83. If you have questions beyond what is there, repost to the list and we can answer

Re: [HCP-Users] How to threshold the task data?

Yes, there are going to be some large z-stats in a analysis involving 440 subjects! Currently, we don't have a tool yet for running a cluster level correction on the surfaces (or even more specifically, the full CIFTI grayordinate space, including both surface vertices and subcortical voxels

Re: [HCP-Users] How to threshold the task data?

Dear Michael, Thank you for your reply! I loaded right hand motor task data into Matlab and see the range of z score is from ~-20 to ~29. If I convert those high z scores, the p value will be just 0. Is that normal? also how can I run a cluster-level correction on the surface map? Best, Xiangyu

Re: [HCP-Users] How to threshold the task data?

Hi, The file has "zstat" in its name, so it is the z-statistic from the Level 3 group model across 440 related subjects ("R440").  You could compute a p-value from a standard normal distribution, but those p-values will not be fully accurate, because as we note in the data release manual, th

[HCP-Users] How to threshold the task data?

Dear all, I tried to run statistical analysis on the task data, for instance, HCP_Q1-Q6_R440_tfMRI_ALLTASKS_level3_zstat1_hp200_s2.dscalar.nii. However I don't know if the data contained z score or beta score, and how to calculate the p value from the task data. Thank you in advance for helping!