In memory of consolidation

How an animal learns, remembers, and uses information to guide adaptive behavior remains one of the most challenging questions in science today. Much progress was made in the twentieth century, and new tools available to neurobiological investigators have accelerated progress in the new century. Nevertheless, the road has been rocky and progress sometimes impeded by periodic polemic debates at a conceptual level. Retrospective examination of the nature of the divisive issues and how they were (or were not) resolved could help steer a new generation of investigators away from similar pitfalls and impasses. The same applies to scientists from other disciplines, recently joining in the “search for the engram,” who might not be aware of the vast literature generated, mainly by psychologists, in the middle decades of the last century. Our purpose here is not to furnish a complete review of this literature, but to provide a historical perspective for …