Structural and functional asymmetry in human parietal opercular cortex

Objective: To evaluate interhemispheric differences of responses in the secondary somatosensory cortex (SII) following median nerve (MN) stimulation and their relation to macrostructural asymmetry of the parietal operculum (PO). Methods: In 16 subjects, MRI-based EEG dipole source analysis was performed for SEP components in the 0–150ms poststimulus interval after left and right MN stimulation. In addition, manual morphometry was used to determine the area of PO in both hemispheres. Results: In the 70–150ms latency range, negative scalp potentials were maximal at temporal electrode sites with peaks at 80 and 110…