Memory



Memory is the ability to store past facts and events.

A simple understanding
In 1989 Peter Burke contributed a theorisation, ‘History as Social Memory’, to Thomas Butler’s collection of essays that were collectively titled Memory; History, Culture and the Mind. Burke introduces his work by reasoning that ‘the traditional view of the relation between history and memory is a relatively simply one. The historian’s function is to be a ‘remembrancer’.

A clever understanding
However, ‘This traditional account of the relation between memory and written history, in which memory reflects what actually happened and history reflects memory, now seems rather too simple’. Burke goes on to comment on the pioneering theorisations of Maurice Halbwachs, published in the 1920s, concerning the ‘social framework of memory’. Whilst the individual ‘remembers’ in a literal sense, ‘it is social groups which determine what is ‘memorable and how it will be remembered.’ The individual will identify with the ways in which their social group chooses to remember what it deems worthy of remembering. This results unavoidably, writes Burke, in individuals and groups remembering ‘a good deal that they have not experienced directly.’

A polemical understanding
When I try to ‘remember’ the Gulf War that took place in the early 1990s, I recall video footage broadcast by news channels, re-enactments in such Hollywood productions as Jar Head and videos games for the Sega Mega Drive like Desert Strike. I will assume that the same can be said of everyone who did not take part in the military engagement; whilst not having experienced the Gulf War directly, we each possess a unique collection of images within our minds depicting certain events that took place during this particular conflict, such as the infamous destruction of a retreating Iraqi Army column; reduced to charred corpses and smoldering heaps of twisted metal by American air forces.

Memory in psychoanalysis
Memory is an important concept in Freudian psychoanalysis. However, this is regarded as pseudoscience by current psychologists. See repressed memory. Freud's idea that most mental activity is unconscious has been vindicated by modern psychology, but his concept of what the unconscious comprised and how memory works is considered to be horrifically wrong by current standards.

Memory in cognitive psychology
Current psychological research has built computational and theoretical models of memory. Memory is divided into these systems and subsystems:
 * Explicit types of memory: Involves direct conscious or verbal recall (sometimes called declarative memory).
 * Episodic/autobiographical: Memory of life experiences.
 * Semantic: Knowledge of language.
 * Implicit types of memory: Involves unconscious types of memory.
 * Procedural: Memory of how to perform a skill or task (not necessarily how to explain it, that would be explicit memory). This usually refers to activities requiring muscle memory such as tying your shoes or playing the piano.
 * Perceptual: Memory of physical stimuli.
 * Priming: The effect whereby a subject recently exposed to a stimulus will recall that stimulus more quickly. Because this can apply to explicit types of memory as well, there is some debate as to where it should be placed within memory models. For this reason, priming is generally considered a "memory mechanism" rather than an independent system on its own.

Memory is further divided into short-term memory and long-term memory. Short-term memory is then sub-divided into types of sensory memory:
 * Iconic: Visual short-term memory, lasting 250-1000 milliseconds.
 * Echoic: Auditory short-term memory, lasting 3-4 seconds.

Working memory is used to refer to models of recall and storage in short-term memory. This term is sometimes conflated with short-term memory. Alan Baddeley's working memory model (pictured at right) is considered to be the standard.

There are two types of amnesia, both of which can occur simultaneously. They are usually caused by some degree of damage to the hippocampus or temporal lobes:
 * Retrograde amnesia: Inability to recall events before brain damage occurred, affects episodic memory for pre-injury memories but new memories can form after the injury.
 * Anterograde amnesia: Inability to form new memories. Pre-injury memories are intact, but episodic memory will often last less than 15-30 minutes, causing confusion. Implicit memory systems are intact and over long periods of time, patients with less severe damage can regain a slight ability to consolidate new episodic memories.

Unlike in cartoons, you can't cure amnesia by thumping people on the head.