Active Brain Regions in Reasoning These images from an fMRI study show that different types of reasoning activate different brain regions. (a) Areas within the parietal lobe were especially active during logical reasoning that is not influenced by prior beliefs (belief-neutral reasoning), whereas (b) an area within the left temporal lobe showed enhanced activity during reasoning that was influenced by prior beliefs (belief-laden reasoning). This suggests that people approach each type of reasoning problem in a different way.