I have come across numerous papers thats state that they conducted spatial correlations between two distinct maps, to quantify the spatial correspondence between such maps. From the articles I’ve read, there is usually a single correlation value that is provided for quantifying the correlation between two maps.

However, I am unable to find how this is done in such articles.

Can anyone provide any ideas as to how these correlations are done?

I am confused as to what is being correlated itself. How is a single correlation value being derived from two different maps? I am having trouble understanding the logic behind it all. Any insight would be great!

Let’s say your maps are both 3D (91x109x91 voxels), and your mask is the same size, with 228453 voxels that are “brain”. When you apply the masker to your images, it unravels the data and you end up with two 1D vectors of 228453 values. You then just correlate those two vectors.