Hello,

I've come across something in my resting state analysis that I think seems kind of strange. I ran 3dfim+ with the Correlation setting using the average in a seed region as the reference, and I used 3dcalc to use the fisher transform for z scores. However I noticed that the z scores I'm getting seem extremely low. In the seed region, it's only a z score of 1.6. Hm...I was expecting something higher. The equation I'm using for the fisher transform is: log((1+a)/(1-a))/2

However after some google searching, apparently FSL uses the following for the fisher transform: sqrt(N-3)*log((1+a)/(1-a))/2, where N is the number of images. But that doesn't make a whole lot of sense to me either because in my case N = 1500, and that hugely inflates the numbers.

Does anybody have any thoughts? Thanks.