Z score of the results of a F test give negative values

[Remi-Gau]

I was looking results in https://nilearn.github.io/stable/auto_examples/04_glm_first_level/plot_first_level_details.html#volume-censoring

Specifically at this image of the results of the F test:

From this section https://nilearn.github.io/dev/auto_examples/04_glm_first_level/plot_first_level_details.html#adding-a-time-derivative-to-the-design

So technically the image shows the Z score of the F test results, but I do find it strange to find negative values in there.

[bthirion]

Yes, we should be explicit on the transform. The point is that it is difficult to interpret F values.