Memory, Amnesia, and the Hippocampal System

In this sweeping synthesis, Neal J. Cohen and Howard Eichenbaum bring togetherconverging findings from neuropsychology, neuroscience, and cognitive science that provide thecritical clues and constraints for developing a more comprehensive understanding of memory.Specifically, they offer a cognitive neuroscience theory of memory that accounts for the nature ofmemory impairment exhibited in human amnesia and animal models of amnesia, that specifies thefunctional role played by the hippocampal system in memory, and that provides further understandingof the componential structure of memory.The authors' central thesis is that the hippocampal systemmediates a capacity for declarative memory, the kind of memory that in humans supports consciousrecollection and the explicit and flexible expression of memories. They argue that this capacityemerges from a representation of critical relations among items in memory, and that such arelational representation supports the ability to make inferences and generalizations from memory,and to manipulate and flexibly express memory in countless ways. In articulating such a descriptionof the fundamental nature of declarative representation and of the mnemonic capabilities to which itgives rise, the authors' theory constitutes a major extension and elaboration of the earlierprocedural-declarative account of memory.Support for this view is taken from a variety ofexperimental studies of amnesia in humans, nonhuman primates, and rodents. Additional support isdrawn from observations concerning the neuroanatomy and neurophysiology of the hippocampal system.The data taken from divergent literatures are shown to converge on the central theme of hippocampalinvolvement in declarative memory across species and across behavioral paradigms.Neal J. Cohen isAssistant Professor in the Amnesia Research Laboratory at Beckman Institute for Advanced Science andTechnology, and in the Department of Psychology at the University of Illinois. Howard Eichenbaum isProfessor of Psychology and Neurobiology at the University of North Carolina, Chapel Hill.