The parietal lobe was the part of the brain that was located in the middle of the cerebral hemispheres. It aided in integrating sensory information.
Doctor Crusher found a small structural defect in Picard's parietal lobe in 2370 that could lead to a number of neurological disorders, including Irumodic syndrome. The defect was so small it required a level-4 neurographic scan to be located. (TNG: "All Good Things...")
When the Pah-wraith-possessed Keiko O'Brien fell down from the upper level of the Promenade in 2373, she suffered a broken femur and a hairline fracture of the right parietal lobe. (DS9: "The Assignment")