Semantic memory
Semantic memory is a type of long-term memory that involves the encoding, storage, and retrieval of factual knowledge, concepts, and definitions, distinguishing it from episodic memory, which pertains to personal experiences and events. This system of memory allows individuals to remember information such as names, dates, and facts without recalling the specific circumstances in which they learned them. Introduced by psychologist Endel Tulving in the early 1970s, the distinction between semantic and episodic memory has led to significant research in understanding cognitive processes and how the brain functions during memory retrieval.
Semantic memory is often likened to a "mental thesaurus," as it encompasses organized knowledge about language and symbols, their meanings, and relationships. Unlike episodic memory, semantic memory is less prone to involuntary loss during retrieval and is thought to be stored in different brain regions, although the exact mechanisms remain debated among researchers. Furthermore, studying semantic memory can enhance our understanding of various cognitive disorders, such as Alzheimer's disease and semantic dementia, potentially aiding in the development of effective treatments for memory impairments. Researchers continue to explore the complexities of this memory system to better understand human learning and retention of knowledge.
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Subject Terms
Semantic memory
Semantic memory is a system of memory involving the encoding, storage, and retrieval of facts, definitions, concepts, and other forms of cognitive knowledge. Semantic memory is often contrasted with episodic memory, the memory of what, where, and when a discrete event happened in one’s own past experience. It is also distinguished from procedural memory, the knowledge of how to accomplish a task.
Scientists study semantic memory and other types of memory to further our understanding of how the brain works and how humans and animals learn and retain knowledge. Studies of how semantic memory is formed, retained, and retrieved may also help researchers develop treatments and therapies for conditions that involve cognitive memory loss, such as Alzheimer’s disease, dementia, amnesia, and traumatic brain injury.
Overview
Estonian Canadian psychologist and neuroscientist Endel Tulving first distinguished episodic memory from semantic memory in 1972 in “Episodic and Semantic Memory,” a chapter in Organization of Memory, which he edited with Wayne Donaldson. At the time, Tulving wrote that he was making the distinction to facilitate discussion, not because he necessarily believed that the two systems were structurally or functionally separate.
According to Tulving, episodic and semantic memory differ in terms of the nature of the information they store, whether the reference is autobiographical or cognitive, the conditions and consequences of retrieval, how much they depend on each other, and their susceptibility to transformation and erasure of stored information by interference. Tulving theorized that semantic memory is essential for language use and likened it to a “mental thesaurus” because it deals with an individual’s organized knowledge of words and symbols, what they mean, what they refer to, and how they are related and used. Unlike episodic memory, semantic memory encodes cognitive information rather than specific personal events; one can remember a fact such as a telephone number without necessarily remembering when and where one learned it. Semantic memory is less vulnerable than episodic memory to involuntary loss or change of information during the act of retrieval. The encoding and storage of information in sensory memory is independent of episodic memory.
Tulving further expounded on episodic and semantic memory in his much-cited 1983 book Elements of Episodic Memory. In this work, he asserts, among other things, the then-controversial theory that episodic memory and semantic memory are functionally distinct. Various experiments have supported Tulving's theory, demonstrating that semantic and episodic tasks are distinct. Since then, neuroimaging models have shown that episodic memory retrieval and semantic memory retrieval involve different parts of the brain. However, researchers remain divided as to whether semantic memory is still stored in some part of the hippocampal formation, as with episodic memory; involves a fully different area of the brain, such as the temporal neocortex; or is distributed among different regions.
There are a variety of disorders that impact semantic memory. Most notable are Alzheimer's disease and semantic dementia, both of which are studied to better understand semantic memory processes. Conversely, research into semantic memory may prove useful in treating or curing these and other memory disorders.
Bibliography
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