Chapter 2: Sensory, Short-Term/Working, and Long-Term Memory

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“Minds are like parachutes – they only function when open”
– Thomas Dewar

Memory (psychology) – processes by which people and other organisms encode, store, and retrieve information. Encoding refers to the initial perception and registration of information. Storage is the retention of encoded information over time. Retrieval refers to the processes involved in using stored information. Whenever people successfully recall a prior experience, they must have encoded, stored, and retrieved information about the experience. Conversely, memory failure-for example, forgetting an important fact-reflects a breakdown in one of these stages of memory.

Memory is critical to humans and all other living organisms. Practically all of our daily activities-talking, understanding, reading, socializing-depend on our having learned and stored information about our environments. Memory allows us to retrieve events from the distant past or from moments ago. It enables us to learn new skills and to form habits. Without the ability to access past experiences or information, we would be unable to comprehend language, recognize our friends and family members, find our way home, or even tie a shoe. Life would be a series of disconnected experiences, each one new and unfamiliar. Without any sort of memory, humans would quickly perish.

Without memory we would be wanderers in a world that was perpetually new and unfamiliar. There are two methods psychologists use to study memory. The first is through self-reporting (introspection), and this approach involves asking participants to record the way they remember and forget. The second method is naturalistic study, and is often experimental in nature. Naturalistic experiments attempt to reproduce events that are more representative of real life, and participants are often asked to remember natural material such as stories, films, events, maps or other visualised material, instead of lists of letters, nonsense syllables or digits

Click on the Link Below:

The Modal Model of Memory1.ppt

The basic characteristics of the model include:

  1. the existence of several linked processing systems;
  2. stage-by-stage processing of information;
  3. a unidirectional flow of information.

The modal model, or multistore model, of memory has become one of the most well-known theoretical memory models. The creators of this approach hypothesize that all parts of the memory system can be divided into two main categories: the control processes and the permanent structure. The control processes are the procedures that one performs in order to encode, maintain, and retrieve memories. The permanent structure includes the different memory stores, which are described in detail below.

The Sensory Store

The sensory store, or the register, records information that comes in through the senses. The information only remains in this store for a few seconds after the stimulus is gone.

The two senses that have been studied the most in terms of their role in memory are vision and hearing. The term “iconic memory” refers to visual impressions in the sensory store. Auditory information that enters the sensory store is called “echoic memory”. One’s iconic memory might hold, for instance, the visual impression of a firework, while the echoic memory will hold for a few seconds the loud noise of the firework.

Most of the information in the sensory store vanishes forever after a few seconds. If all of these information were kept and focused on, we would be so bombarded with stimuli that we would be unable to function. Instead, the brain is constantly going through a selection process to decide which sensory memories are necessary to keep and which should be thrown away. The information that is kept and processed passes into the short-term memory store.

  • visual sensory is very limited. Only seven to nine pieces of information are processed at any given time, and much of that decays rapidly. Information held in visual sensory memory receives only limited processing (less than 0.5 second for iconic register and recall)
  • auditory register and recall (echo) – slightly more than 3 seconds – ability of the echo to retain information seems related to the processing of language
  • Knowledge and context play important role in our perceptual processes – previous knowledge and past experiences!
  • attention = a person’s allocation of cognitive resources to the task at hand
  • attention is maximized if one engages in resource-limited tasks (focusing on one task at a time – e.g. watching television while reading?) and avoid data-limited tasks (tasks that you do not possess much knowledge and skills about) – e.g. learning advanced math without having proper foundation in basic math
  • the role of automatic processes (vs. controlled processes) – require fewer cognitive resources than nonautomated processes

Q: Will being exposed to stimuli from various modality (visual, auditory, gustatory, tactile/haptic, olfactory, etc.) help to enhance memorization of a particular experience? Why do you say so? – enhancement in exposure!

Sensory memory briefly processes a limited amount of incoming stimuli. Visual registers hold about 7 to 9 pieces of information for about 0.5 second. Auditory registers hold about 5 to 7 pieces of information for up to 4 seconds. Incoming stimuli are perceived, then matched to a recognizable pattern, and then assigned a meaning. How much information we can process depends on two things: 1)the complexity of the information and 2)our available resources. Automated tasks are easy to perform because they require fewer attentional resources. Resource-limited tasks are difficult no matter how much attention we allocate because the information itself is deficient.


Short-Term Memory (7 plus/minus 2) – 
the size of the chunks doesn’t really matter!

The short-term memory store holds memories for about thirty seconds. Much of this memory is then forgotten. However, the more important information is then transferred into the long-term memory store. The brain engages in this process naturally, but we can also to an extent control this process by rehearsing, or repeating new memory in order to encode it.

Short-term memory is often referred to as “working memory”. This is because the short-term memory store does not only hold memories, but it also manipulates information and uses it to perform tasks. Working memory consists of three parts. The first component involves perceived sounds, and the second is concerned with visual and spatial information. The third part, the “central executive”, uses information from the first two parts as well as from the long-term memory store.

Like sensory memory, the capacity and duration of short-term memory are quite limited. We hold approximately 7 (plus/minus 2) pieces of information in working memory at a time. This information is forgotten quickly because of interference, decay, and replacement by new information.

The working memory includes a central executive, articulatory loop, and visual-spatial sketch pad. The central executive coordinates the two remaining slave systems, which are responsible for maintenance of verbal and spatial information. Research suggests that each subsystem possesses some unique resources that enable individuals to distribute information processing load.

How do we access information in the STM?

people search the contents of short-term memory in a serial (search one by one) and exhaustive (detailed and meticulous – going through all the items) fashion NOT parallel or search all item in memory simulataneously and self-terminating or ending search when one finds something he/she is looking for

Long-Term Memory

The long-term memory store contains nearly all of what we consider our memory. There are several ways to code memory into this store, some more effective than others. One technique used to improve encoding is elaboration, the connecting of new information to information already in the long-term store. Elaboration may be conscious, such as when mnemonic devices are used, or it may be unconscious.

Note: It is possible for information to enter long-term memory (LTM) without ever entering short-term memory (STM). Researchers have found that individuals with severe STM damage still somehow encode new memories into LTM.

Cognitive Load Theory

States that learning is constrained by limited processing capacity. The higher the cognitive load of the to-be-learned information, the harder it is to learn that information (in other words, minimizing the number of internal mental processes that take place in the ‘mind’ enhances the process of learning)

  • intrinsic cognitive load – caused by the inherent properties of the to-be-learned information and is unalterableother than by schema acquisition
  • extraneous cognitive load – results from the manner in which to-be-learned information is presented or from activities required of the learner

For additional reading and reinforcement:

Sensory memory is everything that you are exposed to at a given instant in time. The best way to think of sensory memory is to consider what happens as you watch a ice-hockey game. You are constantly aware of the location of all the players, but two seconds later as the play continues, you are unable to recall where each player was on the ice.

Short term memory (STM) does not have a lot of capacity and it doesn’t last very long (5-7 seconds). An example of short term memory is when someone gives you a phone number to remember and you forget it before you get to dial the number.

Long term memory (LTM) on the other hand lasts indefinitely, like your student ID number.

It used to be thought that the process of remembering was like an “assembly line” and that stimuli (words, pictures, actions etc.) passed from one station on the assembly line to the next (unidirectional flow of information)

Working Memory: A Modern Advance (needed because STM cannot explain the kind of processes that took place in it)

In the early 1990s, Alan Baddeley (University of York, UK) and his colleagues proposed a newer model of memory: with an additional component known as the working memory.[/vc_column_text][/vc_column][/vc_row]

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