Fig. 5.

Summaries of the group-level spatial parameters encoding different aspects of variability across subjects. The panels are (a) mode overlap; (b) variability in mode strength; (c) variability in mode memberships. Mode overlap is defined as the posterior memberships averaged across all modes, $\frac{1}{M}{\sum }_{\forall m}{\pi }_{vm}$. Variability in mode strength is captured by the weighted average of the posterior standard deviations, $\left({\sum }_{\forall m}{\pi }_{vm}{\sigma }_{vm}\right)/\left({\sum }_{\forall m}{\pi }_{vm}\right)$. Finally, variability in mode memberships is given by the average entropy, in bits, of the membership distributions, $\frac{1}{M}{\sum }_{\forall m}H\left({\pi }_{vm}\right)$.