Semantic memory

Semantic memory is one of the two types of explicit memory (or declarative memory) (our memory of facts or events that is explicitly stored and retrieved). Semantic memory refers to general world knowledge that we have accumulated throughout our lives. This general knowledge (facts, ideas, meaning and concepts) is intertwined in experience and dependent on culture. Semantic memory is distinct from episodic memory, which is our memory of experiences and specific events that occur during our lives, from which we can recreate at any given point. For instance, semantic memory might contain information about what a cat is, whereas episodic memory might contain a specific memory of petting a particular cat. We can learn about new concepts by applying our knowledge learned from things in the past. The counterpart to declarative or explicit memory is nondeclarative memory or implicit memory. Semantic memory is one of the two types of explicit memory (or declarative memory) (our memory of facts or events that is explicitly stored and retrieved). Semantic memory refers to general world knowledge that we have accumulated throughout our lives. This general knowledge (facts, ideas, meaning and concepts) is intertwined in experience and dependent on culture. Semantic memory is distinct from episodic memory, which is our memory of experiences and specific events that occur during our lives, from which we can recreate at any given point. For instance, semantic memory might contain information about what a cat is, whereas episodic memory might contain a specific memory of petting a particular cat. We can learn about new concepts by applying our knowledge learned from things in the past. The counterpart to declarative or explicit memory is nondeclarative memory or implicit memory. The idea of semantic memory was first introduced following a conference in 1972 between Endel Tulving, of the University of Toronto, and W. Donaldson on the role of organization in human memory. Tulving constructed a proposal to distinguish between episodic memory and what he termed semantic memory. He was mainly influenced by the ideas of Reiff and Scheers, who in 1959 made the distinction between two primary forms of memory. One form was entitled 'remembrances', the other 'memoria'. The remembrance concept dealt with memories that contained experiences of an autobiographic index, whereas the memoria concept dealt with those memories that did not reference experiences having an autobiographic index. Semantic memory reflects our knowledge of the world around us, hence the term 'general knowledge' is often used. It holds generic information that is more than likely acquired across various contexts and is used across different situations. According to Madigan in his book titled Memory, semantic memory is the sum of all knowledge one has obtained—whether it be vocabulary, understanding of math, or all the facts one knows. In his book titled 'Episodic and Semantic Memory', Endel Tulving adopted the term 'semantic' from linguists to refer to a system of memory for 'words and verbal symbols, their meanings and referents, the relations between them, and the rules, formulas, or algorithms for influencing them.' The use of semantic memory is quite different from that of episodic memory. Semantic memory refers to general facts and meanings one shares with others whereas episodic memory refers to unique and concrete personal experiences. Tulving's proposal of this distinction between semantic and episodic memory was widely accepted, primarily because it allowed the separate conceptualization of knowledge of the world. Tulving discusses conceptions of episodic and semantic memory in his book titled Elements of Episodic Memory, in which he states that several factors differentiate episodic memory and semantic memory in ways that include Before Tulving's proposal, this area of human memory had been neglected by experimental psychologists. Since Tulving's inception of these distinctions, several experimenters have conducted tests to determine the validity of his hypothesized differences between episodic and semantic memory. Recent research has focused on the idea that when people access a word's meaning, sensorimotor information that is used to perceive and act on the concrete object the word suggests is automatically activated. In the theory of grounded cognition, the meaning of a particular word is grounded in the sensorimotor systems. For example, when one thinks of a pear, knowledge of grasping, chewing, sights, sounds, and tastes used to encode episodic experiences of a pear are recalled through sensorimotor simulation. A grounded simulation approach refers to context-specific re-activations that integrate the important features of episodic experience into a current depiction. Such research has challenged previously utilized amodal views. The brain encodes multiple inputs such as words and pictures to integrate and create a larger conceptual idea by using amodal views (also known as amodal perceptions). Instead of being representations in modality-specific systems, semantic memory representations had previously been viewed as redescriptions of modality-specific states. Some accounts of category-specific semantic deficits that are amodal remain even though researchers are beginning to find support for theories in which knowledge is tied to modality-specific brain regions. This research defines a clear link between episodic experiences and semantic memory. The concept that semantic representations are grounded across modality-specific brain regions can be supported by the fact that episodic and semantic memory appear to function in different yet mutually dependent ways. The distinction between semantic and episodic memory has become a part of the broader scientific discourse. For example, it has been speculated that semantic memory captures the stable aspects of our personality while episodes of illness may have a more episodic nature.