Abstract
This paper introduces a special issue on animal memory and discusses progress made as a result of the present upsurge of interest in the topic, an upsurge that owes much to developments in human cognitive psychology and neuropsychology. Work reported over the last decade has shown that the memory capacity of (at least some) animals is larger—in terms both of number of items stored and of duration of retention—than might previously have been expected. Recent physiological investigations appear to have succeeded in reconciling the effect on memory of hippocampal lesions in humans and non-humans, and further work on the hippocampus may help establish the physical nature of the changes involved in setting up memories. Theoretical accounts of animal memory rely on concepts drawn from cognitive psychology, and various experimental approaches to one particular notion, that animals may rehearse recent information, are discussed. Finally, the research papers of this issue are introduced to show their place in the broad context of memory research.