For the brain activation data, group effects were computed using a random effects model, and the significance threshold was set at 0.001 (uncorrected for multiple comparisons). To control for false positives, we also adopted a AG 013736 mouse cluster size limitation of >10 voxels (Forman et al. 1995). In addition to directly comparing conditions, we performed the post hoc ROI analysis based on mean beta values to explore how the detected regions represented differences among the task × particle interaction. We defined the significantly activated clusters
in the comparisons as ROIs. Mean parameter estimates in each ROI for each subject within each condition were calculated. As we observed statistically significant differences in behavioral data among Inhibitors,research,lifescience,medical particles (see Results), we performed the ROI analysis using the ANCOVA with behavioral data as a covariate to test whether observed brain activity was affected by behavioral differences. In addition, post hoc multiple comparisons were performed (Bonferroni correction). Results Behavioral data Table Table11 summarizes accuracy rates Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical and reaction times (RTs). Accuracy rates did not differ significantly between the particle judgment task and the phonological judgment task and among the three particles as analyzed by the two-way repeated-measures
ANOVA (rANOVA) [task: F1,24 = 0.325, P = 0.574; particle: F2,23 = 1.944, P = 0.166]. Analysis of RTs using the two-way rANOVA revealed a main effect of particle, but no significant difference between the particle judgment task and the phonological judgment task Inhibitors,research,lifescience,medical [task: F1,24 = 1.602, P = 0.218; particle: F2,23 = 6.532, P = 0.003]. The post hoc test showed that the RTs for ga were significantly shorter than those for the other particles (Bonferroni, P < 0.05, “ga < ni,” “ga < o”). Table 1 Behavioral data for target conditions Imaging data Results showed greater activity in the middle frontal gyrus (MFG), the right inferior frontal gyrus (IFG), and the left inferior temporal gyrus (ITG) during the Inhibitors,research,lifescience,medical particle task than the phonological
task (Fig. (Fig.11 and Table Table2).2). Significantly greater activation was not associated with ga, ni, and o during the phonological judgment task than the particle judgment task. Next, we tested for specific areas of brain activity associated with case particle processing. We performed Ketanserin the ANOVA to assess a potential task × particle interaction ([ga in particle task > ga in phonological task] vs. [ni in particle task > ni in phonological task] vs. [o in particle task > o in phonological task]). Results showed that each of the three types of case particle processing were associated with different patterns of activity in the left MFG and the right and left IFG (Table (Table33 and Fig. Fig.22). Table 2 Imaging results for a positive effect of particle task Table 3 Imaging results of a task × particle interaction Figure 1 Brain activity associated with the Particle Judgment task.