Questions about ALFF

Submitted by yaosir on

Dear Chao-Gan,

I have read some ALFF papers, and found that only ALFF with positive  value was shown in the statistical map of one-sample t-test. Does ALFF with negative value make no sense? If so, should I use the mask containing voxels with positive value while analyzing data?

Thank you in advance.

Best,

Vincent

 

YAN Chao-Gan

Thu, 05/28/2015 - 19:34

Hi Vincent,

In one-sample t-test, they are only interested for those have ALFF significantly than the brain mean. If you are interested for those have ALFF significantly lower than brain mean, you can pay attention to the negative values.

No, including the brain will be more informative. The group difference may occur at the regions without high ALFF.

Best,

Chao-Gan