Operculum (brain)
Operculum (brain)
The operculum in the brain refers to parts of the cerebral cortex that cover the insula, a region tucked deep inside the brain. The opercula come from the frontal, parietal, and temporal lobes, and some descriptions also mention an occipital operculum.
Together, the opercula act like lids that cover the insula. The insula itself sits like an island (the word insula means island) inside the lateral groove of the brain (the lateral sulcus) and is partly hidden by the opercula.
The frontoparietal operculum covers the upper part of the insula from the front to the back and lies over the precentral and postcentral gyri near the central sulcus. The parietal operculum forms the roof of the lateral sulcus and includes part of the brain’s secondary somatosensory cortex.
Development: The insular opercula form as the brain develops in the womb. The insula begins to invaginate (fold inward) around weeks 14–16 of fetal development, and by full term the opercula have grown to cover the insula. This process is called opercularization and happens roughly between weeks 20 and 22 of pregnancy.
Case reports: Albert Einstein’s brain has been studied to see whether it had parietal opercula. Researchers disagree: some say his brain did have them, others say it did not. Einstein’s lower parietal lobe was reported to be about 15% larger than average, a finding discussed in relation to his cognitive abilities.
See also: Circular sulcus of the insula; Sulcus lateralis.
This page was last edited on 1 February 2026, at 20:49 (CET).