Semantic memory
Information about Semantic memory
Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge unrelated to specific experiences. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory. The counterpart to declarative, or explicit memory, is procedural memory, or implicit memory.[1]
Semantic memory includes generalized knowledge that does not involve memory of a specific event. 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 semantic feature-comparison model, proposed by Smith, Shoben, and Rips, describes memory as being composed of feature lists for different concepts. Some lists will contain features that are required for the specific concept, while other lists will contain features that are typically representative of that concept.
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 encoding of information leading to semantic memory does not have its physiological basis in the hippocampus. (Vargha-Kadem et al.)
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.
Semantic memory includes generalized knowledge that does not involve memory of a specific event. 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.
Organization
The spreading activation model, proposed by Collins and Loftus (1975), describes semantic memory as being organized like a map of connected concepts.The semantic feature-comparison model, proposed by Smith, Shoben, and Rips, describes memory as being composed of feature lists for different concepts. Some lists will contain features that are required for the specific concept, while other lists will contain features that are typically representative of that concept.
Location of semantic memory in the brain
The cognitive neuroscience of semantic memory is a somewhat controversial issue with two dominant views.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 encoding of information leading to semantic memory does not have its physiological basis in the hippocampus. (Vargha-Kadem et al.)
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.
Notes
1. ^ Tulving, E., & Schacter, D.L. (1990). Primary and Human memory systems. Science, 247, 301 – 306.
External Links
- http://www.mtsu.edu/~sschmidt/Cognitive/semantic/semantic.html#VI.%20Conclusions%20on%20Semantic%20Memory
- http://www.newscientist.com/article.ns?id=dn10012&feedId=brain_rss20
Memory | |
|---|---|
| Long-term memory | Procedural memory - Declarative memory (Episodic memory, Semantic memory) |
| other | Working memory - Short-term memory |
In psychology, memory is an organism's ability to store, retain, and subsequently retrieve information. Traditional studies of memory began in the realms of philosophy, including techniques of artificially enhancing the memory.
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Understanding is a psychological process related to an abstract or physical object, such as, person, situation, or message whereby one is able to think about it and use concepts to deal adequately with that object.
An understanding is the limit of a conceptualization.
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An understanding is the limit of a conceptualization.
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Knowledge is defined (Oxford English Dictionary) variously as (i) expertise, and skills acquired by a person through experience or education; the theoretical or practical understanding of a subject, (ii) what is known in a particular field or in total; facts and information or
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Episodic memory refers to the memory of events, times, places, associated emotions, and other conception-based knowledge in relation to an experience. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory.
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Declarative memory is the aspect of human memory that stores facts. It is so called because it refers to memories that can be consciously discussed, or declared. It applies to standard textbook learning and knowledge, as well as memories that can be 'travelled back to' in
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Procedural memory, also known as implicit memory or unconscious memory, is the long-term memory of skills and procedures, or "how to" knowledge (procedural knowledge).
As compared with declarative memory, it is governed by different mechanisms and different brain circuits.
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As compared with declarative memory, it is governed by different mechanisms and different brain circuits.
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Cognitive neuroscience is an academic field concerned with the scientific study of biological mechanisms underlying cognition, with a specific focus on the neural substrates of mental processes and their behavioral manifestations.
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In animals, the brain or encephalon (Greek for "in the skull"), is the control center of the central nervous system, responsible for behavior. The brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing,
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Episodic memory refers to the memory of events, times, places, associated emotions, and other conception-based knowledge in relation to an experience. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory.
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The temporal lobes are part of the cerebrum. They lie at the sides of the brain, beneath the lateral or Sylvian fissure. Seen in profile, the human brain looks something like a boxing glove. The temporal lobes are where the thumbs would be.
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The hippocampus is a part of the forebrain, located in the medial temporal lobe. It forms a part of the limbic system and plays a part in memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain.
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The entorhinal cortex (EC) is an important memory center in the brain. The EC forms the main input to the hippocampus and is responsible for the pre-processing (familiarity) of the input signals.
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REF or Ref is a three-letter abbreviation that may refer to:
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- Reference, something that refers to something else
- Referee, in sports
- Reform Party, in politics
- The Ref, a film
- Row echelon form, a mathematical matrix construct
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The hippocampus is a part of the forebrain, located in the medial temporal lobe. It forms a part of the limbic system and plays a part in memory and spatial navigation. Humans and other mammals have two hippocampi, one in each side of the brain.
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Episodic memory refers to the memory of events, times, places, associated emotions, and other conception-based knowledge in relation to an experience. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory.
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Cognition is a diffuse term, used in different ways by different disciplines. In psychology, it refers to an information processing view of an individual's psychological functions.
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neocortex (Latin for "new bark" or "new rind") is a part of the brain of mammals. It is the top layer of the cerebral hemispheres, 2-4 mm thick, and made up of six layers, labelled I to VI (with VI being the innermost and I being the outermost).
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The primary auditory cortex is the region of the brain that is responsible for processing of auditory (sound) information.
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Function of the Primary Auditory Cortex
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The term visual cortex refers to the primary visual cortex (also known as striate cortex or V1) and extrastriate visual cortical areas such as V2, V3, V4, and V5.
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The anterior end of the hemisphere is named the frontal pole. (See also frontal lobe.)
The posterior end is named the occipital pole. (See also occipital lobe.)
The anterior end of the temporal lobe, the temporal pole. (See also temporal lobe.
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The posterior end is named the occipital pole. (See also occipital lobe.)
The anterior end of the temporal lobe, the temporal pole. (See also temporal lobe.
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Semantic dementia (SD) is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non-verbal domains. The most common presenting symptoms are in the verbal domain however (with loss of word meaning) and it is therefore often
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In psychology, memory is an organism's ability to store, retain, and subsequently retrieve information. Traditional studies of memory began in the realms of philosophy, including techniques of artificially enhancing the memory.
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Long-term memory (LTM) is memory, stored as meaning, that can last as little as 30 seconds or as long as decades. It differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around 30 seconds.
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Procedural memory, also known as implicit memory or unconscious memory, is the long-term memory of skills and procedures, or "how to" knowledge (procedural knowledge).
As compared with declarative memory, it is governed by different mechanisms and different brain circuits.
..... Click the link for more information.
As compared with declarative memory, it is governed by different mechanisms and different brain circuits.
..... Click the link for more information.
Declarative memory is the aspect of human memory that stores facts. It is so called because it refers to memories that can be consciously discussed, or declared. It applies to standard textbook learning and knowledge, as well as memories that can be 'travelled back to' in
..... Click the link for more information.
..... Click the link for more information.
Episodic memory refers to the memory of events, times, places, associated emotions, and other conception-based knowledge in relation to an experience. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory.
..... Click the link for more information.
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Working memory is a theoretical framework within cognitive psychology that refers to the structures and processes used for temporarily storing and manipulating information.
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Short-term memory, sometimes referred to as "primary," "working," or "active" memory, is said to hold a small amount of information for about 20 seconds.
Estimates of short-term memory capacity vary - from about 3 or 4 elements (i.e.
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Estimates of short-term memory capacity vary - from about 3 or 4 elements (i.e.
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