**Description **

Based random field
theory, multiple comparisons can be done. The *p*-value after multiple comparisons
correction is usually referred as the corrected *p*-value. It computes
p-values on triangular meshes that is topologically equivalent to a sphere. It
has been applied to both the human cortex and the human hippocampus surface.

**MATLAB Codes
**(MATLAB 6.1. implementation)

This is modified from Keith Worsley's original fMRIstat package.

- surf_tstat_threshold.m
computes the t random field based thresholding corresponding to a given
corrected
*p*-value.

The corrected p-value can be computed on the following sample cortical surface.

- [tri,coord,nbr,normal]=mni_getmesh('outersurface.obj');
- trisurf(tri, coord(1,:),coord(2,:),coord(3,:));

- mni_getmesh.m loading polygonal mesh data into MATLAB.
- Outsurface.obj sample cortical surface mesh (MNI mesh).

**Documentation **

- Chung, M.K., Robbins,S., Dalton, K.M., Davidson, Alexander, A.L., R.J., Evans, A.C. 2005. Cortical thickness analysis in autism via heat kernel smoothing. NeuroImage 25:1256-1265.
- Chung,
M.K., Robbins, S., Evans, A.C. 2005. Unified
statistical approach to cortical thickness analysis. Information
Processing in Medical Imaging (IPMI).
Lecture Notes in Computer Science. Springer. (acceptance rate < 26%). in
press.
- Worsley,
K.J., Marrett, S., Neelin, P., Vandal, A.C., Friston, K.J., and Evans, A.C.
1996. A
unified statistical approach for determining significant signals in images
of cerebral activation.
*Human Brain Mapping*,**4**:58-73. - Shen, L., Saykin, A., McHugh, T., West, J., Rabin, L., Wishart, H., Chung, M.K., Makedon, F. 2005. Morphometric analysis of 3D surfaces: appliction to hippocampal shape in mild cognitive impairment. 6th International conference on computer vision, pattern recognition and image processing in conjunction with 8th joint cocnference on information sciences (CVPRIP). 2005.
- Pantazis, D., Leachy, R.M., Nichols, T.E., Styner, M. 2004. Statistical surface-based morphometry using a non-parametric approach. IEEE International Symposium on Biomedical Imaging (ISBI).

Last update 05/9/2005.