記憶の二過程

Abstract

It has been suggested that a short term store of the information received by an organism is vulnerable and a period of consolidation is necessary before a memory trace is established in a stable form. In animal studies, the period required for the fixation of the memory was evaluated from the extent of the retrograde amnesia produced by an electroconvulsive shock after a training trial. The temporal gradient, however, was found to vary with problems used, which raised a question about the fixation time. Contemporary evidence suggested that the retrograde amnesic effect induced by a convulsive treatment might reveal a retrieval failure rather than a consolidation disturbance. It was based on the fact of memory recovery by an exposure to reminder cues, selective amnesic effect associated with a similar motivational state, and a memory disruption evoked by a reactivation with presentation of a cue stimulus followed by an convulsive treatment. The present interpretation on the two-phase of the memory was reviewed, and a hippocampal function in particular was discussed with special reference to rehearsal process related to reinforcement.