Fig 1.
Main effect of condition (testable vs. non-testable).
Left medial and left lateral view of clusters which showed a significant effect of condition. Colors represent F-values (blue in regions where activation was greater for non-testable propositions and yellow and orange in regions where activation was greater for testable propositions). Areas activated by testable propositions included dorsolateral prefrontal cortex (DLPFC) and posterior cingulate cortex. Areas activated by non-testable propositions included inferior frontal gyrus, superior temporal gyrus, and an anterior region of the superior frontal gyrus.
Table 1.
Significant Clusters for All Analyses.
Fig 2.
Main effect of rejection of a proposition.
Left medial view of clusters which were significantly activated when a proposition was rejected. Colors represent F-values. Areas which were more active when rejecting a proposition include the dorsal anterior cingulate cortex (ACC). No areas were significantly more active when accepting a proposition.
Fig 3.
Interaction between acceptance of a proposition and condition (testable vs. non-testable).
(A) Left lateral view. Colors represent F-values. (B) Activation levels of inferior frontal gyrus cluster shown in Fig 3A. This region was most active when rejecting a non-testable proposition. Error bars represent standard error of the mean.
Fig 4.
Colors represent F-values. Regions which were more active when a proposition was deemed certainly true or false (“Definitely” or “Not at all”) included medial prefrontal cortex, caudate, posterior cingulate gyrus, and a region of the temporal lobe near the temporo-parietal junction. No areas were more active during uncertainty.
Fig 5.
Interaction between certainty and condition (testable vs. non-testable).
(A) Left lateral view. Colors represent F-values. All areas were more active during certainty that a non-testable proposition was true or false. (B) Activation levels of insula cluster as shown in Fig 5A. This region was more active when a non-testable proposition was deemed certainly true or certainly false. Error bars represent standard error of the mean.
Testable Propositions
Non-Testable Propositions