This included the left IFG, pre-supplementary motor area (preSMA), and extensive portions of the STG bilaterally. For Reversed Speech, the TYP group produced activation in regions associated with auditory processing namely bilateral activity along the STG. The contrast of Speech greater than Reversed Speech selleck kinase inhibitor highlighted a clearly left-lateralised pattern of activation involving the left IFG and preSMA (see Fig. 3). For the SIB group (N = 6),
patterns of activation for all contrasts were similar to those seen in the TYP group (see Supplementary Tables for SIB activation descriptions); the extent of activations above the statistical threshold was somewhat reduced in the SIB compared to the TYP group, which may be due to the smaller number of participants in the former (N = 6) compared to the latter (N = 13). For the SLI group (N = 8), however, the extent of activity above the statistical threshold was severely reduced such that for Speech there were no supra-threshold voxels in the left IFG and the clusters of activity in the STG bilaterally were reduced in extent and the height of the statistic (see Supplementary Tables NU7441 molecular weight for SLI activation descriptions). In sum, within-group patterns of activation for the three contrasts (see Fig. 2 and Fig. 3, and Supplementary Tables) are indicative of functionally similar patterns between all groups, suggesting that the groups did not differ in their general
response to the conditions. However, the average intensity of activation did differ between groups, with activation in the SLI group mostly sub-threshold.1 The differences in patterns of activation among the three groups described above were tested directly by statistical contrasts between them. Compared to the TYP group, the SLI group had significantly reduced activity in the left IFG (pars orbitalis) during the Speech condition (see Fig. 4) and in the left STG and right putamen for the contrast
of Speech greater than Reversed (see Fig. 5 and Table 3 for all between-group comparisons). Activity Thymidine kinase in the SLI group was also reduced relative to the TYP group in the left IFG for the Speech greater than Reversed contrast; however, this difference did not pass our inclusion criterion with an extent of only 8 voxels. Compared to the SIB group, the SLI group had significantly reduced activity in the IFG and STG bilaterally for both the Speech and the Speech greater than Reversed Speech contrasts (see Fig. 4 and Fig. 5). Overall, these results indicate a reduced speech-specific response in this SLI group. The comparison of the SIB and TYP groups revealed greater activation in the SIB group in the right cerebellar lobule VI during the Speech condition (see Fig. 4 and Table 3). There were no significant differences between the SIB and TTP groups in the other contrasts. There were no significant group differences in the Reversed Speech contrast. Laterality indices based upon the frontal and temporal lobes for the three contrasts are presented in Fig. 6.