Differentiate between short-term memory and working memory
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Home / People / Behaviour / Difference Between Working Memory and Short Term Memory Show
Working memory and Short term memory are two terms that often confuse most people, although there is a key difference between the two. Memory has a very complex definition. Due to its complex nature memory is defined and described in different ways. Working memory and short-term memory are two terms that are used synonymously. But it is important to understand that they actually mean two different things. These two terms are mostly used in psychological studies and neuroscience. What is Working Memory?The term “working memory” was introduced by Miller, Galanter and Pribram in 1960. Working memory is a theoretical concept which is used in cognitive psychology and neuroscience. If working memory could be considered as a system, it is the system which holds transitory information and processes which allows this information to be manipulated. Some processes that working memory holds are reasoning and comprehension. The subsystems of working memory may hold verbal memories, visual memories and controllers that allow manipulation. Sometimes working memory is used alternatively with the term short term memory. But these two are different. In fact, short-term memory is a part of working memory. In addition, working memory holds controllers which allow integration, disposal, and retrieval of short-term memory information. These processes are subjected to age. Therefore, working memory tends to decline with age. Several researchers have identified the parts of the brain such as frontal cortex, parietal cortex, anterior cingulate, and basal ganglia that are crucial for working memory’s functions. What is Short Term Memory?Short term memory is a concept that was born with the conscious mind theories of Freudian psychology. It is also known by the names primary memory or active memory. Short term memory is the information that is stored in mind within few seconds to approximately 30 seconds. This is temporary. Most of the information is quickly forgotten, but if the information is rehearsed and used by some process, it can move into the deeper levels of mind known as long-term memory. Short-term memory capacity varies from person to person. Generally it can hold up to seven plus or minus two (5-9) elements. Short term memory is active and readily available to be used during a short duration. Short term memory is a part of the working memory. What is the difference between Working Memory and Short Term Memory?Definitions of Working Memory and Short Term Memory:Working Memory: Working memory is the system which comprises of short-term memory, and also the structures and processes which help in storing and manipulating information temporarily. Short Term Memory: Short term memory is the temporary memory which is spanning in the range of few seconds. Characteristics of Working Memory and Short Term Memory:System: Working Memory: Working memory is a system. Short Term Memory: Short term memory is one of the subsystems of the working memory. Image Courtesy: 1. “NIA human brain drawing” by National Institute for Aging, a branch of NIH. [Public Domain] via Commons 2. “Sleeping while studying” by Psy3330 W10 – Own work. [CC BY-SA 3.0] via Commons Short-term memory acts as a kind of “scratch-pad” for temporary recall of the information which is being processed at any point in time, and has been referred to as "the brain's Post-it note". It can be thought of as the ability to remember and process information at the same time. It holds a small amount of information (typically around 7 items or even less) in mind in an active, readily-available state for a short period of time (typically from 10 to 15 seconds, or sometimes up to a minute).
For example, in order to understand this sentence, the beginning of the sentence needs to be held in mind while the rest is read, a task which is carried out by the short-term memory. Other common examples of short-term memory in action are the holding on to a piece of information temporarily in order to complete a task (e.g. “carrying over” a number in a subtraction sum, or remembering a persuasive argument until another person finishes talking), and simultaneous translation (where the interpreter must store information in one language while orally translating it into another). What is actually held in short-term memory, though, is not complete concepts, but rather links or pointers (such as words, for example) which the brain can flesh out from it's other accumulated knowledge. However, this information will quickly disappear forever unless we make a conscious effort to retain it, and short-term memory is a necessary step toward the next stage of retention, long-term memory. The transfer of information to long-term memory for more permanent storage can be facilitated or improved by mental repetition of the information or, even more effectively, by giving it a meaning and associating it with other previously acquired knowledge. Motivation is also a consideration, in that information relating to a subject of strong interest to a person, is more likely to be retained in long-term memory.
The term working memory is often used interchangeably with short-term memory, although technically working memory refers more to the whole theoretical framework of structures and processes used for the temporary storage and manipulation of information, of which short-term memory is just one component. The central executive part of the prefrontal cortex at the front of the brain appears to play a fundamental role in short-term and working memory. It both serves as a temporary store for short-term memory, where information is kept available while it is needed for current reasoning processes, but it also "calls up" information from elsewhere in the brain. The central executive controls two neural loops, one for visual data (which activates areas near the visual cortex of the brain and acts as a visual scratch pad), and one for language (the "phonological loop", which uses Broca's area as a kind of "inner voice" that repeats word sounds to keep them in mind). These two scratch pads temporarily hold data until it is erased by the next job. Although the prefrontal cortex is not the only part of the brain involved - it must also cooperate with other parts of the cortex from which it extracts information for brief periods - it is the most important, and Carlyle Jacobsen reported, as early as 1935, that damage to the prefrontal cortex in primates caused short-term memory deficits. The short-term memory has a limited capacity, which can be readily illustrated by the simple expedient of trying to remember a list of random items (without allowing repetition or reinforcement) and seeing when errors begin to creep in. The often-cited experiments by George Miller in 1956 suggest that the number of objects an average human can hold in working memory (known as memory span) is between 5 and 9 (7 ± 2, which Miller described as the “magical number”, and which is sometimes referred to as Miller's Law). However, although this may be approximately true for a population of college students, for example, memory span varies widely with populations tested, and modern estimates are typically lower, of the order of just 4 or 5 items.
The type or characteristics of the information also affects the number of items which can be retained in short-term memory. For instance, more words can be recalled if they are shorter or more commonly used words, or if they are phonologically similar in sound, or if they are taken from a single semantic category (such as sports, for example) rather than from different categories, etc. There is also some evidence that short-term memory capacity and duration is increased if the words or digits are articulated aloud instead of being read sub-vocally (in the head). The relatively small capacity of the short-term memory, compared to the huge capacity of long-term memory , has been attributed by some to the evolutionary survival advantage in paying attention to a relatively small number of important things (e.g. the approach of a dangerous predator, the proximity of a nearby safe haven, etc) and not to a plethora of other peripheral details which would only interfere with rapid decision-making. "Chunking" of information can lead to an increase in the short-term memory capacity. Chunking is the organization of material into shorter meaningful groups to make them more manageable. For example, a hyphenated phone number, split into groups of 3 or 4 digits, tends to be easier to remember than a single long number. Experiments by Herbert Simon have shown that the ideal size for chunking of letters and numbers, whether meaningful or not, is three. However, meaningful groups may be longer (such as four numbers that make up a date within a long list of numbers, for example). With chunking, each chunk represents just one of the 5 - 9 items that can be stored in short-term memory, thus extending the total number of items that can be held.
It is usually assumed that the short-term memory spontaneously decays over time, typically in the region of 10 - 15 seconds, but items may be retained for up to a minute, depending on the content. However, it can be extended by repetition or rehearsal (either by reading items out loud, or by mental simulation), so that the information re-enters the short-term store and is retained for a further period. When several elements (such as digits, words or pictures) are held in short-term memory simultaneously, they effectively compete with each other for recall. New content, therefore, gradually pushes out older content (known as displacement), unless the older content is actively protected against interference by rehearsal or by directing attention to it. Any outside interference tends to cause disturbances in short-term memory retention, and for this reason people often feel a distinct desire to complete the tasks held in short-term memory as soon as possible. The forgetting of short-term memories involves a different process to the forgetting of long-term memory. When something in short-term memory is forgotten, it means that a nerve impulse has merely ceased being transmitted through a particular neural network. In general, unless an impulse is reactivated, it stops flowing through a network after just a few seconds. Typically, information is transferred from the short-term or working memory to the long-term memory within just a few seconds, although the exact mechanisms by which this transfer takes place, and whether all or only some memories are retained permanently, remain controversial topics among experts. Richard Schiffrin, in particular, is well known for his work in the 1960s suggesting that ALL memories automatically pass from a short-term to a long-term store after a short time (known as the modal or multi-store or Atkinson-Schiffrin model). However, this is disputed, and it now seems increasingly likely that some kind of vetting or editing procedure takes place. Some researchers (e.g. Eugen Tarnow) have proposed that there is no real distinction between short-term and long-term memory at all, and certainly it is difficult to demarcate a clear boundary between them. However, the evidence of patients with some kinds of anterograde amnesia, and experiments on the way distraction affect the short-term recall of lists, suggest that there are in fact two more or less separate systems. What is the difference between STM and WM?Typical tasks measuring STM are simple span tasks, while WM is commonly measured using complex span tasks. Simple span tasks generally require the participant to maintain a collection of symbols, elements, or spatial positions over a brief period of time (Unsworth and Engle, 2007b).
What are the differences between working memory and longNeuroscience makes a clear distinction between the two. It holds that working memory is related to temporary activation of neurons in the brain. In contrast, long-term memory is thought to be related to physical changes to neurons and their connections.
What is your short term and working memory capacity?Most adults can store between 5 and 9 items in their short-term memory. This idea was put forward by Miller (1956) and he called it the magic number 7. He though that short term memory could hold 7 (plus or minus 2 items) because it only had a certain number of “slots” in which items could be stored.
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