Coding - This means changing input into a format that the brain can use. The three main ways memory can be coded are:
- Orthographic/visual - storing how something looks.
- Phonological/acoustic - storing how something sounds.
- Semantic code - storing what something means.
Storage - Information is kept in different memory stores for different amounts of time. Each store has a different:
- Memory capacity - how much can be stored.
- Memory duration - how long information can be stored.
Retrieval - This is when information is taken out of a memory store and used.
- Recall - bringing information to mind.
- Recognition - deciding whether information has been encountered before.
The Multi Store Model of Memory
Sensory Input - information from all the senses.
Sensory register - brain registers information. (ATTENTION PAID)
Short term memory (REHEARSAL) (response)
Long term memory (RETRIEVAL SENDS BACK TO STM) (response)
- Capacity - large capacity store
- Duration - last for a brief period of time (2 seconds)
- Coding (info stored in its raw unprocessed form)
- Capacity - 7+- 2 Capacity - Limitless
- Duration - 30 seconds Duration - Lifetime
- Coding - Phonological Coding - Semantic
Claims and Components of Multi Store Model
Claims - The multi store model is concerned with the structure of memory. It proposes that information flows one way through to model.
Components - Information is inputted from our 5 senses into the sensory register. This register has a large capacity and information is stored here for a duration of 2 seconds (and stored in its raw form)
If this information is paid attention to, it will flow through to the short term memory, or lost if attention isn't paid. This memory store has a capacity of 7+-2 and a duration of 30 seconds. The coding in this store is phonological. Once here, a response can be made or the information can be rehearsed in order to flow through to the long term memory. This memory store has a limitless capacity and a duration of a lifetime. The coding in this store is semantic. Once here a response can be made, or the information can be stored and retrieved at a later date.
SODG of the Multi Store Model
Supporting - Murdock Serial Position Curve - Primacy Effect - the tendency for the first items presented in a series to be remembered better or more easily. Recency effect - the principle that the most recently presented items or experiences will most likely be remembered best. This shows support because when presented with a list of words we have a tendancy to remember the first few words and the last few words, forgetting the words between.
Opposing - Shallice and Warrington - KF suffered brain damage following a motorcycle accident. KF's STM was severely impaired, however teir LTM was relatively intact. He could remember things from before his accident, but also after. This opposes the model because his memories could not flow through his STM to his LTM.
- The model is highly influential in the work of cognitive psychologists, being the first model of its kind to attempt to explain memory. This model formed the basis for the working memory model.
- There is considerable evidence for the existence of the STM and the LTM, with research also proving that there are two seperate memory stores.
- A criticism of the MSM is that it is over simplified, as it assumes there are single short-term and long-term memory stores. However further research now indicates that there could be several types of STM such as one for verbal and non verbal sounds.
- There is also evidence to suggest that there are different types of LTM, rather than just the one that is suggested by the MSM, such as procedural, episodic and semantic memories.
Types of Long Term Memory
Episodic LTM - refers to the ability to recall events, and has therefore been likened to a diary of events. These memories are 'time - stamped' and therefore we can remember when they happened. You have to make a conscious effort to recall these memories. Research evidence is Tulving, who suggests that episodic and semantic LTMs involve different areas of the brain and are therefore different types of LTM.
Semantic LTM - The store contains our knowledge of the world, including the facts we have made sense of, e.g. the meaning of words. We don't necessarily remember when we learned the information, however these stored facts are continously being added to. Research evidence is Kroenig who found that Alzheimer sufferers were not as good as non-sufferers at identifying imaginary animals when using rule-based training. This suggests that semantic memory involves different processes and brain areas.
Procedural LTM - This store contains details about our actions, skills and the way we do things. Not a great deal of effort or conscious effort is needed to recall these e.g. how to drive a car. Research evidence is Finke et al who used the case study of PM, a musician who suffered damage to areas of the brain. Episodic and semantic LTM were affected, but they still had the ability to read and play music.
Evaluation of Types of LTM
Real life application - psychologists have been able to better the lives of individuals, knowing that they are able to resolve or target any issues that are linked to the specific memory type. As episodic memory is the type of memory that is most affected by mild cognitive impairment, this highlights the usefulness of being able to distinguish between the different types of LTM and allows for specific treatment to be developed.
Clinical evidence - famous case studies such as patient HM and Clive Wearing, both had impaired episodic memory due to amnesia, for example HM needed the concept of what a dog was explaining to him again. However, he could still understand the meaning of words (semantic LTM) and how to tie his shoelaces (procedural LTM). CW could still read music, sing and play the piano. This evidence supports Tulvings idea that there are different LTM stores and that one store can be damaged whilst the others remain unaffected.
Although psychologists are very interested in studing people with brain injuries, there are many flaws in the methods that are used to conduct these studies. Studies such as HM and CW are case studies based on one person. As no two cases are the same, this makes the difficult to generalise. Also, many of the studies have a lack of control over all sorts of different variables and therefore it can be argued that they aren't reliable.
Cohen and squire disagree with Tulving's types of LTM. They argue that although there is evidence for procedural being a stand alone type, the episodic and semantic memories are stored together in what they call the declarative memory.
Claims and Components of Working Memory Model
Claims - The model creates an explanation of the structure and function of short term memory. It is concerned with the part of our mind that is active when we are temporarily storing and manipulating. The model consists of four components. Each are different in terms of coding and capacity.
- The central executive - this area is focussed on the process that monitors incoming data. It also makes decisions and allocates slave systems to tasks. This has a very limited storage capacity.
- The phonological loop - the first slave system deals with auditory information. The coding is acoustic. It preserves the order in which information arrives. It has two subsections - the phonological store - a store of the words you hear, and the articulary process - a process that allows maintenance rehearsal (repeating words or sounds in a loop to keep them in working memory while they are needed). The capacity is believed to be 2 seconds worth of what you can say.
- The visuo-spatial sketchpad - the second slave system that stores visual and spatial information, for example faces or surroundings. It has a limited capacity of about 3 or 4 objects. It can be divided in to the visual cache, which stores visual data, or the inner scribe, which records the management of objects in the visual field.
- The episodic buffer - the third slave system is a temporary store for information. It integrates the visual, spatial and verbal information processed by other stores. It maintains a sense of time sequencing and can record events that are happening. It has a limited capacity of about 4 chunks of information.
SODG for Working Memory Model
Gathercole and Baddeley - visuospatial sketchpad - participants had difficulty tracking a moving point of light whilsts decribing angles on a hollow letter F. This shows support as it indicates that the visuospatial sketchpad is a seperate slave system.
Baddeley et al - phonological loop - participants able to recall more short words in the serial order than longer words. Shows support for the phonological loop as it proves that it's capacity depends on how long it takes to say words, rather than the actual number of words.
Baddeley - central executive - participants found it hard to create a list of numbers whilst simultaneously pressing numbers and letters on a keyboard. This shows support for the central executive as the two tasks were competing for the use of resources in this part of the WMM at the same time, therefore proving that the central execute has limited capacity.
Alkhalifa - episodic buffer - patient who had severely impaired LTM could still demonstrate they had the capacity to hold up to 25 prose items. This suggests existence of the episodic buffer that allows temporary storage of integrated information
Forgetting - Interference Theory
As we store more and more information in the LTM, some of this information becomes confused. This is interference. Interference is most likely to occur between similar information.
There are two types of interference:
Proactive interference, where old information interferes with new information.
Retroactive interference, where new information interferes with old information.
SODG for Interference Theory
Supporting - Jenkins and Dallenbach support interference theory. They gave participants a list of nonsense syllabeles to learn, half having to learn the list before going to sleep, and half learning the list first thing in the morning. This test was 8 hours later. Recall was higher in the group which slept, which shows support because there was no new information to interfere with the syllabeles.
Baddeley and Hitch support interference thoery. They asked rugby players to recall the names of team players they had played earlier in the season. If they had larger number of games between the recall then they had poorer recall. This shows that their knowledge had been interfered with, showing proactive interference.
Schimdt supports interference theory. They showed participants maps of their childhood area. The more frequently a partcipant had moved, the less street names they could recall, showing retroactive interference.
Strength - Evidence from lab studies - lab experiments control the effects of irrelevant influences and thus give us confidence that interference theory is a valid explanation for at least some forgetting.
Also, it can be applied to at least some real life situations.
However, the use of artificial tasks makes interference theory much more likely in the lab. Interference may not be as likely an explanation in real life.
Claims and Components for Retreival Failure Theory
Claims - Memory depends on cues being available. Cues are additional pieces of information that help us find the information we need. Forgetting happens because we do not have the right cues.
Components - When we encode a memory, we also store information that occured around it e.g. the way we felt, the place we were in.
If we are not in a similar situation when we try to recall something, we will not remember it.
The greater the similarity between the encoding situation and the retrieval situation, the greater the chance of recalling a memory. This is called the encoding specificity principle.
There are two types of cues:
Context dependent forgetting - these are cues to do with the environment we are in e.g. sights, sounds, smells. We forget things if these context cues are not present.
State-dependent forgetting - These are cues to do with our internal feelings, e.g. mood, emotion, alcohol. We forget things if we are not in the same state when we try to remember it.
SODG for Retrieval Failure Theory
Supporting - Godden and Baddeley - 18 participants from a diving club had to learn 38 unrelated 2 or 3 syllabele words. They were randomly allocated to one of four conditions: 1. learn on land, recall on land. 2. learn underwater, recall underwater. 3. learn on land, recall underwater. 4. learn underwater, recall on land. Mean number of words recalled in condition 1 = 13.5, condition 2 = 11.4, condition 3 = 8.6, condition 4 = 8.4. This shows that recall is higher when the situations are similar, which supports context-dependent forgetting, as they must have got cues from the environment.
Lang et al - They made Ps who were afraid of snakes and spiders learn words whilst looking at pictures of the animals. Recall was much better when the Ps were made to be afraid than when they were relaxed. This shows that the mood you are in affects how well you can learn and recall things.
Opposing - Schmidt - they showed participants maps of their childhood area. The more frequently they moved, the less street names they could remember, showing retroactive interference.