Figure 3. fMRI experiments results.

On the left, two overlaid SPMs maps (yellow and red) are presented on a T1 template image of a single subject. Yellow indicate areas showing significant main effects of featural changes; red indicates areas showing significant correlations of brain responses to second-order spatial relational change with the impact of such changes on individual participants’ behavioral person-discriminations, in a separate behavioral study (see main text). In the middle column, the corresponding SPMs are overlaid on a sagital T1 template image, depicting each effect separately. For presentation purposes all SPM maps are thresholds at P < 0.005. In the right columns, plots of parameters estimates taken from the maxima (MNI coordinates given in central column) are plotted for each of the four experimental conditions; and scatter plots are shown for the effects of second-order spatial-relation changes on fMRI activity (coordinates above) against the behavioral impact of such changes on person-discrimination (in red circles). For comparison, responses in relation to the behavioral impact of featural change on the fMRI response to featural change (no correlation found) are also plotted for the same maxima (black pluses). A. Separate featural and second-order spatial-relation effects in posterior occipital cortices (LOS, IOG, respectively). B. Convergence of featural and second-order spatial-relation effects (latter related to individual differences in behavioral impact of relational changes) in right FFG. Key to acronyms: 2^nd.diff, changes of second-order relations; 2^nd.rep, repetition of second-order relations; Feat − feature.