Neurobiology of an Attribute Model of Memory: Role of Prefrontal Cortex
Raymond P. Kesner Pamela Jackson-Smith University of Utah
There are many theoretical schemata one can select to organize the neurobiological basis of the structure of memory. On a psychological level these schemata can vary from a single to a multiple task analysis, from a single or dual to a multiple memory analysis, and/or from a single to a multiple attribute analysis. On a neurobiological level these schemata can vary from a synapse, a single cell, or a neural region to the brain as a whole. We have decided that the best representation of memory might be in the form of multiple attributes, and that its neurobiological mediation is to be analyzed at the level of a neural region. Thus, the psychological unit of analysis is an attribute (e.g., space) and the neural unit of analysis is a neural region (e.g., hippocampus).
Based on earlier suggestions by Underwood ( 1969) and Spear ( 1976), I have proposed that any specific memory is composed of a set of features or attributes that are specific and unique for each learning experience ( Kesner, 1980). In most animal experiments there are a set of at least five salient attributes that characterize mnemonic information. In humans one would also add a linguistic attribute. These are labeled space, time, affect, sensory perception, and response. A spatial attribute within this framework involves the coding and storage of specific stimuli representing places or relationships between places, which are usually independent of the subject's own body schema. It is exemplified by the ability to encode and remember maps and to localize stimuli in external space.
A temporal attribute involves the encoding and storage of specific stimuli or sets of spatially or temporally separated stimuli as part of an episode marking or tagging its occurrence in time, that is, separating one specific episode from previous or succeeding episodes.