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I am using nilearn and nipy package for python processing FMRI data. When computing mask, it says:

Compute and write the mask of an image based on the grey level This is based on an heuristic proposed by T.Nichols: find the least dense point of the histogram, between fractions m and M of the total image histogram.

and

This is based on an heuristic proposed by T.Nichols: find the least dense point of the histogram, between fractions lower_cutoff and upper_cutoff of the total image histogram.

In both masking functions of nilearn and nipy. Who is T.Nichols? I wasn't able to google him/her out.

here are the links to the functions:

http://nipy.org/nipy/stable/api/generated/nipy.labs.mask.html

https://nilearn.github.io/building_blocks/generated/nilearn.masking.compute_epi_mask.html

Josh
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fast tooth
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1 Answers1

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I know very little about fmri, but as @strongbad points out, surely it is Professor Thomas Nichols at Warwick.

I'm not sure what the authoritative reference is, but Luo and Nichols (2003) might be worth a look. They state:

We construct a histogram based on all non-tail data (10th to 90th percentile) and use the location of the minimum bin as the antimode estimate.

Luo, W. L., & Nichols, T. E. (2003). Diagnosis and exploration of massively univariate neuroimaging models. NeuroImage, 19(3), 1014-1032. http://www-personal.umich.edu/~nichols/Docs/fMRIvis.pdf

Jeromy Anglim
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