History in the Study of Learning and Memory

Abstract

Learning is the acquisition of information, knowledge, and experiences from natural environments as well as social interactions. Memory is termed to be the storages and the subsequent retrievals of these acquired messages through recall, recollection and representation. The acquisition of exogenous signals is mainly based on associative learning despite an assumption of non-associative learning. The storage of associated signals is integrative in nature, which is essential for cognitive events and emotional reactions. In the meantime, the processes of cognition, emotion and behavior can be memorized. Associative memory includes the integrative storage of exogenous and endogenous associated signals. Learning and memory have been studied many centuries. Neuronal substrates potentially relevant to learning and memory have been presented in the following names, such as memory trace, engram, cell assemblies, associative memory cells, and so on. In terms of mechanisms underlying these processes, most of the studies indicate that these neuronal substrates are widely distributed in the cerebral brains. Although the natures of memory traces or engrams have not well been documented, cell assemblies are hypothetically to be interconnected neurons. Recently, associative memory cell has been detected. Associative memory cells are neurons with mutual synapse innervations in coactivated brain regions and are able to encode multiple signals carried by these innervations. The recruitment of associative memory cells as well as the refinement of these interconnected neurons and their synapses are thought to be basically for memory formation. In this chapter, author intends to review the histories in the study of learning and memory as well as the trend of revealing neural substrates for information storage and memory retrieval.