What is Declarative Memory?
Declarative memory supports the ability to acquire new facts and events and depends on the integrity of the hippocampus Opens in new window and anatomically related structures in the medial temporal lobe Opens in new window and diecephalon.
Declarative memory is a form of long-term memory Opens in new window that involves knowing something is or was the case. It is devoted to conscious recollection or processing of names, dates, places, facts, events, and so forth. These are entities that are thought of as being encoded symbolically and that thus can be described with language.
Sometimes known as explicit memory, declarative memory includes memory for abstract representations such as facts, rules, concepts and events and as such is characterized by knowing that.
Take for example,
- You know that biology is the study of living things,
- that there are 365 days in a year,
- that the capital of the United States is Washington, D.C.,
- that an elephant is bigger than a flea.
- You also know that your name is not Monty Python,
- that Earth is not flat, and
- that Mickey Mouse is not a real mouse.
According to Terr (1994), declarative memory is essentially a conscious record of learned information, of which it involves thinking and attaching words to what has been learned and then remembered.
In terms of function, declarative memory is specialized for fast processing and learning. New information can be entered into the declarative memory system on the basis of a single trial or experience.
In terms of rules of operation declarative memory is fallible: one forgets names, dates, places, and so forth. Although there are compelling demonstrations of long-term remembering of lessons learned in high school and college (e.g., foreign language vocabulary), a great deal of forgetting from declarative memory occurs literally minutes, hours, and days after an experience.
Declarative memories are declarative knowledge
A lot of the things we are taught in school are declarative knowledge, but you can acquire declarative knowledge through reading magazines and books, browsing the Web, visiting museums, talking to friends, walking around your neighborhood, peering through a microscope, and in a thousand other ways.
The defining characteristic of declarative knowledge is that it can be expressed. Usually it is expressed in words, but it can be expressed in other ways, including pictures and gestures.
Distinctions between Declarative and Nondeclarative Memories
Declarative memory is fast, flexible, and fallible, in that memory traces deteriorate over time and are subject to retrieval failures and high levels of reconstruction. Nondeclarative memory Opens in new window, in contrast, is slow, reliable and inflexible.
Declarative memory enables us to identify a flower or to recall a particular experience in a narrative form and is probably most vulnerable to distortion.
Recollection in nondeclarative memory Opens in new window is not associated with a specific episode, and learning proceeds gradually as a result of repeated practice. See more distinctive features between declarative and nondeclarative memories Opens in new window.
Types of Declarative Memory
Cognitive psychologist Endel Tulving (1972) of the University of Toronto proposed that declarative memories be further subdivided into semantic and episodic memories.
- Episodic Memory
Episodic memory Opens in new window contains memories of personally experienced events and the context in which they occurred. Such memories are stored in a spatiotemporal context.
For example, if an individual remembers being given her first bicycle at her sixth birthday party, then s/he is likely to recall who was at the party, when and where it was held, what the weather was like, the games that were played and the cake that was eaten.
Episodic memory is important for recognizing people, places and events encountered in the past, but it is nevertheless highly susceptible to reconstruction and loss.;
The majority of memory work for clinicians focuses primarily on episodic memory.
- Semantic Memory
Semantic memory, in contrast to episodic memory, contains internal representations of the world, specifically general factual knowledge, concepts, rules and language, independent of context. Thus, an individual may know that the capital of France is Paris, but s/he may have no personal recollection of when, where or how s/he first learned this fact.
According to Tulving (1972), semantic memory Opens in new window is ‘a mental thesaurus, organized knowledge a person possesses about words and other verbal symbols, their meanings and referents’.
Semantic memory appears to be less vulnerable to reconstruction and loss than episodic memory Opens in new window. Despite the distinctive differences between episodic and semantic memory, they are highly interactive and can be seen as part of the declarative memory system.
Some information can be stored in both episodic and semantic memory. It is certainly possible to store in the semantic memory autobiographical details such as the number of siblings one has without having to access and remember whole scenarios about oneself in relation to the siblings and past experiences.
Thus, we can build up a semantic knowledge about an object through our past experiences from which we have abstracted and generalized.
However, when we encounter an object that is personally meaningful, we initially apply generalized and abstracted knowledge to the object at the recognition stage.
Implicated in this are two processes, known as bottom-up and top-down processing Opens in new window. Bottom-up processing refers to the processing of information driven primarily by the actual input, whereas top-down processing is essentially driven by the individual’s previous knowledge of the input.