Discuss (controversial) issues

各位老师，大家好，我的一篇文章大修，是研究基因型与疾病关系的。

我首先用VBM，做了基因型与组间（正常/患病）的方差分析，得到有两个cluster存在交互作用，然后用这两个cluster做全脑的FC，再做FC的方差分析

审稿人除了指出样本和效应量的问题以外，还提出“Is there a bias for picking up ROI seeds correlated with GENE and then evaluating the relationship between GENE with the FC connected to these seed ROIs?'

不知道审稿人的这个问题怎么回答合适？多谢指教！

Dear experts,

I have a question about the paper "Cluster failure: Why fMRI inferences for spatial extent have inflated false-positive rates" and Cox's paper  "AFNI and Clustering: False Po

Dear Experts,

for the analysis of our ALFF/fALFF and Reho values we use the z-maps within a graymatter mask. However the mask was only applied after calculation and standardization of those values for the group contrasts. Is this an unusual procedure? or should I use only the voxel within the mask for creating the z-maps?

Thanx in advance for feedback

Maria

Dear Forum,

I downloaded the rsfMRI baseline from the Parkinson's Progressive Marker Initiave, but the odd thing is that all fMRIs look like the image below. There is a shift motion or slope every 8 slices but there is no information on internet about this kind of acquisition. Also articles using this database doesn't mention this characteristic in their Methods section. I wonder if somebody in this Forum has worked before with this database and faced this problem.

Many thanks, Luis R. Peraza

Hi experts,

Hi experts, 

I'm quite new to REST for the  analysis of  my resting state data. I want to do functional connectivity analysis but i have problems when i want to regress out motion parameters and ROI signales from my data. 

I don't understand the way to arrange my covariates  (rp files and RoiSignals) in a specific folder ; so i can use them in the Regress Out Covariates step. Can you help me with that please ? 

Thank you, 

Best regards, 

Hi all.

I am quite new to REST and SPM, so my question might sound silly.

I want to do statistical analysis on ReHo and ALFF maps. I watched the DPARSF course videos and it says that in order to perform Statistical analyisis (One- Sample t Test), I have to calculate mReHo-1. 

correct me if I am wrong, It means that the null hypothesis would be : mReho-1 = 0. Which in turn means that I would be looking for voxels in which mReho is greater than one. 

I do not quite get the theory behind this... why not compare the results with 0 instead of 1? 

Dear Chaogan,

I need some help from you to response the comments from the reviewer. In the analysis, I used degree centrality to measure the developmental changes in hubs with age, but the reviewer questioned it, and proposed questions like 'Why have the authors used only degree centrality as the measure to identify hubs ? Are the results robust against other graph centrality measures such as the  betweenness centrality ?'

Could you please give me some suggestion on how to response it? Thanks so much.

Best,

Yaqiong

Hi,

I have a group of 90 test subjects and I calculated FC for the left Amygdala. I used the DPABI statistical toolbox and calculated a one-sample t-test for the FC zmaps for the ROI with base 0. The results show very high t-values up to 40 in the seed region itself and up to 20 in other regions (see attached picture). I cannot correct for multiple comparison because any voxel with a t-value that high will be significant even when using FDR. I'm not sure if this is correct or if I did something wrong?

Any helpful comments appreciated

Hi everyone,