spm_list: spm_list
In jpellman/spmR: Statistical Parametric Mapping in R

Description Usage Arguments See Also

spm_list characterizes SPMs (thresholded at u and k) in terms of excursion sets (a collection of face, edge and vertex connected subsets or clusters). The corrected significance of the results are based on set, cluster and voxel-level inferences using distributional approximations from the Theory of Gaussian Fields. These distributions assume that the SPM is a reasonable lattice approximation of a continuous random field with known component field smoothness.

The p values are based on the probability of obtaining c, or more, clusters of k, or more, resels above u, in the volume S analysed = P(u,k,c). For specified thresholds u, k, the set-level inference is based on the observed number of clusters C, = P(u,k,C). For each cluster of size K the cluster-level inference is based on P(u,K,1) and for each voxel (or selected maxima) of height U, in that cluster, the voxel-level inference is based on P(U,0,1). All three levels of inference are supported with a tabular presentation of the p values and the underlying statistic:

Set-level - c = number of suprathreshold clusters - P = prob(c or more clusters in the search volume)

Cluster-level - k = number of voxels in this cluster - Pc = prob(k or more voxels in the search volume) - Pu = prob(k or more voxels in a cluster) - Qc = lowest FDR bound for which this cluster would be declared positive

Peak-level - T/F = Statistic upon which the SPM is based - Ze = The equivalent Z score - prob(Z > Ze) = prob(t > T) - Pc = prob(Ze or higher in the search volume) - Qp = lowest FDR bound for which this peak would be declared positive - Pu = prob(Ze or higher at that voxel)

Voxel-level - Qu = Expd(Prop of false positives among voxels >= Ze)

x,y,z (mm) - Coordinates of the voxel

The table is grouped by regions and sorted on the Ze-variate of the primary maxima. Ze-variates (based on the uncorrected p value) are the Z score equivalent of the statistic. Volumes are expressed in voxels.

Clicking on values in the table returns the value to the Matlab workspace. In addition, clicking on the co-ordinates jumps the results section cursor to that location. The table has a context menu (obtained by right-clicking in the background of the table), providing options to print the current table as a text table, or to extract the table data to the Matlab workspace.

Summary list of local maxima for entire volume of interest:
TabDat = spm_list('List',SPM,hReg,[Num,Dis,Str])

List of local maxima for a single suprathreshold cluster:
TabDat = spm_list('ListCluster',SPM,hReg,[Num,Dis,Str])