general_image_conjunction#

qx_mri.general.general_image_conjunction(imgf, maskf, method, effect, q, data, psign)#

general_image_conjunction(imgf, maskf, method, effect, q, data, psign)

Reads image file, computes conjunction using general_conjunction and saves results. Accepts image of significance estimates and computes conjunction for 1 <= u <= n. Results at each step are thresholded using FDR q.

Based on Heller et al. (2017). NeuroImage 37, 1178–1185. (https://doi.org/10.1016/j.neuroimage.2007.05.051).

Parameters

--imgf (str):

Input file, a z-score image file of concatenated individual files.

--maskf (str, default 'nonzero'):

Optional mask image

  • missing or empty ... takes all non-zero voxels

  • 'nonzero' ... takes all non-zero voxels

  • 'all' ... takes all voxels.

--method (str, default 'Fisher'):

Method of calculating conjunction p:

  • 'Simes' ... pooling dependent p-values (eq. 5)

  • 'Stouffer' ... pooling independent p-values (eq. 6)

  • 'Fisher' ... pooling independent p-values (eq. 7).

--effects (str, default 'all'):

The effect of interest:

  • 'pos' ... positive effect only (one tailed test)

  • 'neg' ... negative effect only (one tailed test)

  • 'all' ... both effects (two tailed test).

--q (float, default 0.05):

The FDR q value at which to threshold.

--data (str, default 'z'):

The values in image

  • 'z' ... z-values

  • 'p' ... p-values.

--psign (str | matrix | cell array | nimage, default ''):

In case of two-tailed test for p-values input, an image that includes signs for the effect direction if p-values are not signed. It can be signed z-scores image.

Output files

'_Conj_p'

Conjunction results, p-values for u = 1 to u = n.

'_Conj_z'

Conjunction results, z-scores for u = 1 to u = n.

'_Conj_FDR_p_<q>'

p-values thresholded with FDR.

'_Conj_FDR_z_<q>'

Z-scores thresholded with FDR.

'_Conj_FDR_c_<q>'

Image of frequency of passing threshold.

Notes

For the rest of arguments see general_conjunction.m