The Hippocampus Each brain hemisphere contains a hippocampus, a small region that looks like a sea horse tucked in the medial temporal lobe. Its primary function is to remember novel events. Since sensory information flows through the neocortex, it is up to the neocortex to determine that an experience is novel in order to present it to the hippocampus. It does so either by failing to recognize a particular set of features (for example, a new face) or by realizing that an otherwise familiar situation now has unique attributes (such as your spouse’s wearing a fake mustache).

