eelbrain.xhemi(ndvar, mask=None, hemi='lh', parc=True)

Project data from both hemispheres to hemi of fsaverage_sym

Project data from both hemispheres to the same hemisphere for interhemisphere comparisons. The fsaverage_sym brain is a symmetric version of fsaverage to facilitate interhemisphere comparisons. It is included with FreeSurfer > 5.1 and can be obtained as described here. For statistical comparisons between hemispheres, use of the symmetric fsaverage_sym model is recommended to minimize bias 1.

  • ndvar (NDVar) – NDVar with SourceSpace dimension.

  • mask (bool) – Remove sources in “unknown-” labels (default is True unless ndvar contains sources with “unknown-” label).

  • hemi ('lh' | 'rh') – Hemisphere onto which to morph the data.

  • parc (bool | str) – Parcellation for target source space; True to use same as in ndvar (default).


  • lh (NDVAr) – Data from the left hemisphere on hemi of fsaverage_sym.

  • rh (NDVar) – Data from the right hemisphere on hemi of fsaverage_sym.

See also


lower level function for morphing


Only symmetric volume source spaces are currently supported.



Greve D. N., Van der Haegen L., Cai Q., Stufflebeam S., Sabuncu M. R., Fischl B., Brysbaert M. A Surface-based Analysis of Language Lateralization and Cortical Asymmetry. Journal of Cognitive Neuroscience 25(9), 1477-1492, 2013.