Group (N = 7) average grey matter estimates of a) , b) DBV, and c) OEF, with error bars indicating inter-subject standard deviation, for the L model, and 1C and 2C models; (s) indicates spatial regularization. Two-way ANOVA and pair-wise comparisons show that the 1C and 2C models produce similar estimates as the L model, although the DBV estimates are different except in the non-regularized 1C model. The 1C and 2C models with spatial regularization produce estimates of OEF that are not statistically significantly different from those of the L model.