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Semantic memory refers to the memory of meanings, understandings, and other factual knowledge; in contrast to episodic memory. Semantic and episodic memory together make up the broader category of declarative memory, which is one of the two major divisions in memory. The counterpart to declarative, or explicit memory is called nondeclarative, procedural, or implicit memory, depending on which research team is queried. Image File history File links Wiki_letter_w. ... In psychology, memory is the ability of an organism to store, retain, and subsequently recall information. ... Meaning, studied in philosophy and linguistics, as well as being central to the fields of literary theory and critical theory, the philosophical field of epistemology, and some branches of psychoanalysis, is a difficult concept to pin down. ... Look up understanding in Wiktionary, the free dictionary. ... Personification of knowledge (Greek Επιστημη, Episteme) in Celsus Library in Ephesos, Turkey. ... Episodic memory, or autobiographical memory, a sub-category of declarative memory, is the recollection of events. ... It has been suggested that Explicit_memory be merged into this article or section. ... Procedural memory, also known as implicit memory, is the long-term memory of skills and procedures, or how to knowledge. ...

Generalized knowledge that does not involve memory of a specific event is called semantic memory. For instance, you can answer a question like "Are wrenches pets or tools?" without remembering any specific event in which you learned that wrenches are tools.

The cognitive neuroscience of semantic memory is a somewhat controversial issue with two dominant views: The field of cognitive neuroscience concerns the scientific study of the neural mechanisms underlying cognition and is a branch of neuroscience. ...

1. On the one hand, many researchers and clinicians believe that semantic memory is stored by the same brain systems involved in episodic memory. These include the medial temporal lobes (MTL) and hippocampal formation. In this system, the hippocampal formation "encodes" memories, or makes it possible for memories to form at all, and the cortex stores memories after the initial encoding process is completed.
   • Recently, new evidence has been presented in support of a more precise interpretation of this hypothesis. The hippocampal formation includes, among other structures: the hippocampus itself, the entorhinal cortex, and the perirhinal cortex. These latter two make up the "parahippocampal cortices". Amnesics with damage to the hippocampus but some spared parahippocampal cortex were able to demonstrate some degree of intact semantic memory despite a total loss of episodic memory. This strongly suggests that semantic memory has its physiological basis in these parahippocampal cortices. (Vargha-Kadem et al.)
2. Other researchers believe the hippocampus is only involved in episodic memory and spatial cognition. This then raises the question where semantic memory may be located. Some believe semantic memory lives in temporal neocortex. Others believe that semantic knowledge is widely distributed across all brain areas. To illustrate this latter view, consider your knowledge of dogs. Researchers holding the 'distributed semantic knowledge' view believe that your knowledge of the sound a dog makes exists in your auditory cortex, whilst your ability to recognize and imagine the visual features of a dog resides in your visual cortex. Perhaps all these representations are indexed by the left temporal pole, a region particularly vulnerable to damage in semantic dementia.

The cited reference was subsequently withdrawn from print. Please see Science 1997 Aug 22; 277(5329):1117 for erratum. The temporal lobe is part of the cerebrum. ... The hippocampus is located in the medial temporal lobe of the brain. ... The entorhinal cortex (EC) is an important memory center in the brain. ... ref or REF may refer to row echelon form Rapid Equipping Force Reform Party referee Raymond E. Feist, REF is a common nickname for the fantasy author. ... The hippocampus is located in the medial temporal lobe of the brain. ... Episodic memory, or autobiographical memory, a sub-category of declarative memory, is the recollection of events. ... Look up Cognition in Wiktionary, the free dictionary. ... The neocortex (Latin for new bark or new rind) is a part of the brain of mammals. ... The primary auditory cortex the region of the brain which is responsible for processing of auditory (sound) information. ... Visual cortex is the term applied to both the primary visual cortex (also known as striate cortex or V1) and upstream visual cortical areas also known as extrastriate cortical areas (V2, V3, V4, V5). ... Semantic dementia (SD) is a progressive language disorder characterized by fluent, empty speech and loss of word meaning. ...

See also

• Declarative memory
• Procedural memory
• Semantic dementia

It has been suggested that Explicit_memory be merged into this article or section. ... Procedural memory, also known as implicit memory, is the long-term memory of skills and procedures, or how to knowledge. ... Semantic dementia (SD) is a progressive language disorder characterized by fluent, empty speech and loss of word meaning. ...

References

• Vargha-Kadem, F., Gadian D., Watkins, K., Connelly, A., Paesschen, W., Mishkin, M. (1997) Differential effects of early hippocampal pathology on episodic and semantic memory. Science, 277, 376-381.

External links

• Semantic memory pinpointed in the brain
• http://www.mtsu.edu/~sschmidt/Cognitive/semantic/semantic.html#IV.%20Network%20Models%20of%20Semantic%20Memory