Learning and Memory


An organism's chances for survival are greatly impacted by its ability to learn from previous experience and form memories to modify future behaviour. The search for the engram, the physical trace of a memory in the brain, has resulted in a wealth of data beginning to uncover how memories are stored at the molecular‐cellular level. Despite terminology that suggests a unitary nature, modern definitions of memory support the idea of multiple memory systems, unique in both structure and function. Experiments utilising a multitude of techniques support a structural distinction between different types of memory in humans and animals. The method of memory formation appears to be conserved across memory systems, each following a pattern of encoding, storage and retrieval. Though individual memory capabilities do vary slightly across the population, extreme cases have been observed in either direction, such as hyperthymesia (superior autobiographical memory) and amnesia associated with neurological damage (e.g. Alzheimer's disease).

Key Concepts:

  • Modern neuroscience accepts multiple brain–memory systems.

  • Memory can be defined in terms of temporal longevity, quality of information, or brain circuits required in its formation and storage.

  • The medial temporal lobe is a critical system in the formation and storage of declarative memories about facts and events.

  • Amnesiacs with bilaterally damaged medial temporal lobe system have intact procedural memories.

  • Understanding the mechanisms of learning and memory is vital to developing treatments for cognitive declines that occur with aging and neurological diseases such as Alzheimer's dementia.

Keywords: learning; memory; declarative memory; nondeclarative memory; conditioning; multiple memory systems

Figure 1.

Temporal divisions of memory. Information enters short‐term memory through a process of learning. Through consolidation, which often requires some rehearsal of the information, information can enter long‐term memory. A memory can be be retrieved or recalled, from either short‐ or long‐term memory.

Figure 2.

Contemporary memory taxonomy based on information content and circuitry.



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Further Reading

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Reilly, Melissa A, and Kim, Jeansok J(Jan 2013) Learning and Memory. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0000172.pub2]