Figure 3.

(A) Three-Way interaction of an ANOVA (conditions vs. baseline), including the factors Mode (forward/backward speech), Speech rate (8/18 syl/s), and Training (pre-/post-training) exemplified for two single subjects—the one with no residual vision and the normal sighted, both with comparable training success [p < 0.005 uncorrected, k = 10 voxels]. Variance was calculated across five runs per subject and training stage. (B) Hemodynamic effects within one selected cluster from the ANOVA regarding each session (pre-, post-training as well as the intermediate measurement): (i) the right primary visual area (V1) of the blind individual and (ii) the right temporal pole (Tp) of the sighted subject. Values of percent signal change are shown separately for the moderately fast (8 syl/s) and ultra-fast (18 syl/s) condition vs. baseline (left plot) as well as separately for the conditions and the null-event vs. the implicit baseline each (right plot). In the blind subject, right V1 activation during the ultra-fast speech condition increased after the training, whereas the reversed condition showed a decrease (note that also the null-event increased). Since no V1 activation or deactivation was found at pre-training measurements, functional reorganization is suggested. By contrast, since the Tp activation of the sighted person already existed in the pre-training stage during moderately fast speech processing and increased post-training during ultra-fast speech perception, redistribution is assumed to be the neuro-plastic mechanism.