To evaluate the fMRI paradigm, we assessed whether, similar to a recent study of mental imagery by Maguire and colleagues [30], the DMN regions would show more activity during the imagined events (Int-Enc) than during the externally-presented events (Ext-Enc). As shown in Figure 2 and Table 3, a memory (successful/unsuccessful)×orientation (internal/external) repeated measures ANOVA indicated that the DMN regions, except for HF and mPFC, all showed a significant main effect of orientation, reflecting higher overall activity for Int-Enc than Ext-Enc. Together with the previous findings by Maguire and colleagues, these results clearly indicate that participants were performing the Int-Enc/Ext-Enc task as instructed.
