Enhanced Learning Protects Brain against Effects of Amnesic Treatments

The vast majority of experiments dealing with the effects on memory of interference with normal activity of the brain support the century-old theory of memory consolidation because of the consistent finding that administration of a variety of treatments shortly after a learning experience produces amnesia. This detrimental effect diminishes as the interval between learning and treatment increases, until the treatments become ineffective. Evidence has accumulated, however, that does not fit the consolidation theory. Treatments that produce amnesia of learning mediated by positive and negative reinforcers become innocuous when the same learning is overtrained. This effect has been found independently of the amnesic agents used and the mode of their administration.

Based on the kind of data reviewed in this chapter, two models have been proposed to help explain the protective effect of enhanced training against amnesic treatments. More experiments are under way to test the validity of these models. If the new data are consistent with the predictions that can be derived from these models, then it will be possible to think about the brain as having at least two different ways to store learned information, depending on whether it is dealing with normal or enhanced learning.