The hippocampus is a subcortical structure that receives input from the perirhinal cortex, has been identified as a vital locus of memory formation for associations, transitive learning, spatial mapping, and other complex representations. It also appears to be central to our ability to reconstruct the past through recall, as opposed to our ability to experience the simple familiarity of items in our current environment, for which the perirhinal cortex is sufficient. Patients with circumscribed hippocampal damage may be specifically impaired in tests of recall, while their recognition memory of single items is found to be relatively preserved.