Unsolved Mysteries: The Hippocampus

Abstract

The continuing explosion of scientific interest in the hippocampus began in the 1950s, initiated in large part by the recognition of the importance of the observations of hippocampectomized monkeys made by Klüver and Bucy and the remarkable memory loss of patient H. M. following temporal lobe surgery. Subsequent to these studies, research and theories about the hippocampus grew exponentially in number and diversity. As yet, no theory of hippocampal function explains all of the phenomena discovered in the clinic or laboratory. In this article, experimental results that have been forgotten or ignored in most theories are presented. Adequate theories of hippocampal function must account for known, reliable postsurgical behavioral observations and consider the conditions under which anomalies are noted. Comprehensive theories will require new approaches in which the interactions of the hippocampus with the central nervous system are understood.