memory

• 1: What is coding? 2: What is capacity? 3: What is duration?


  1: the way that information is changed and stored in memory. 2: The amount of information that can be held in the memory store. 3: The length of time information can he held in memory.
• Who did research on coding for both STM and LTM, describe it:

  -Alan Baddeley.

  -Procedure: He gave different lists of words to four groups of patients to remember. There were either semantically similar words or semantically dissimilar words, acoustically similar words or acoustically dissimilar words. Participants were shown the original words and were asked to recall them in the correct order.

  -Findings: when they did this task immediately (recalling from STM) they tended to do worse with acoustically similar words. When recalling after 20 minutes (so from LTM) they did worse with semantically similar words.

  -These findings suggest that information is coded acoustically in STM and semantically in LTM.
• Who did research on capacity of STM?


  Jacobs- by measuring digit span.

  Miller- by making observations of every day practice.
• Jacobs and Miller did research on capacity of STM, describe their research and their findings:

  -Jacobs found out the capacity of STM by measuring digit span. For example, the researcher reads out four digits and the participant recalls out loud these in the correct order. If this is correct then the researcher reads out five digits and so on until the participant cannot recall the order correctly. This indicates the individuals digit span. Mean span for digits: 9.3 items. Mean span for letters: 7.3 items.

  -Miller notes that things often come in sevens in every day practice e.g seven days of the week, seven deadly sins etc. He called seven the 'magic number' and thought that the capacity of STM was 7 plus or minus two items. But he also noted that we can recall 5 words as easily as 5 letters which we do by chunking- grouping sets of digits into units or chunks.
• Who did research on duration for STM? Who did research on duration for LTM?

  -Peterson and Peterson- trigram study.

  -Bahrick et al- high school year books.
• Describe research on duration of STM by Peterson and Peterson:


  They found that with a distractor task, e.g counting backwards, accurate recall of a trigram (constant syllables) after 3 seconds was 80% but after 18 seconds this dropped to less than 10% suggesting that information decays in STM after 18 seconds, without rehearsal.
• Describe research on duration of LTM by Bahrick et al:


  -He studied American participants between the ages of 17-74 on their recall using people's high school year books in various ways including a photo recognition test.

  -70% of participants could still recognise their peers after 48 years, showing that LTM may last up to a life time for some material.
• What is STM?


  The limited capacity store. Coding= acoustic. Capacity= between 5-9 items. Duration= 18-30 seconds.
• What is LTM?


  The permanent memory store. Coding= semantic. Capacity= unlimited. Duration: Up to a lifetime.
• AO3: evaluate Baddeley's study study into coding (1 strength, 1 weakness)

  Strength: Identified a clear difference between two memory stores. Later research showed that there are exceptions to Baddeley's findings. But the idea that STM uses mostly acoustic coding and LTM mostly semantic has stood the test of time and has been important in our understanding of the memory system- leading to the MSM.

  Weakness: Used artificial stimuli instead of meaningful material material. E.g: the word lists had no meaning to participants. Baddeley's findings cannot tell us much about coding in every day life. When processing more meaningful info it has been suggested that people may use semantic coding for every day tasks. This means that his research has limited application and low ecological validity.
• AO3: evaluate one strength of Jacobs study and one weakness of Millner's study.

  -Strength of Jacobs: his study has been replicated. His study is a very old one so likely lacked adequate controls which meant some participants digit span may have been underestimated because they were distracted during tests (confounding variable). His findings, despite this, have been confirmed by other, better controlled studies since. This suggests his study is a valid test of digit span in STM.

  -Weakness of Millner: He may have overestimated STM capacity. Cowhan reviewed other research and concluded that the capacity of STM is only about 4 plus or minus one chunk. This suggests that the lower end of Millners estimate (5) is more appropriate than seven items.
• AO3: evaluate one weakness to Peterson and Peterson's study and a strength to Bahrick et als:

  Weakness to Peterson + Peterson: the stimulus material was artificial. The study isn't completely irrelevant because we do sometimes try to remember meaningful materials like phone numbers but even so, recalling constant syllables doesn't reflect most every day memory activities where what we're trying to remember is more meaningful. This means the study lacks in external/ecological validity.

  Strength to Bahrick et als: High external validity- the researchers investigated meaningful memories like people's names and faces. When studies were conducted with meaningless pictures to be remembered recall rates were lower (e.g Shepard). This suggests that Bahrick et als findings reflect a more 'real' estimate of the duration of LTM.
• Who designed the MSM and when? What is it?

  Atkinson and Shiffrin (1968). It is the first attempt at a theoretical model of human memory and described memory as a linear process made of three unitary stores linked by processing- STM, LTM and the sensory register.
• What is the sensory register? How does memory pass through it?

  The memory store for each of our five senses. Coding is modality specific (it depends on the sense) e.g visual info=iconic memory and acoustic info=echoic memory. It has a very high capacity and a very brief duration of less than half a second.

  -environmental stimuli is processed by the senses and if it is payed attention too it passes further into the memory system (to STM).
• What is STM? How does memory pass through it?

  STM has a limited capacity of 5-9 items after which earlier memories are displaced in favour of newer ones. Information in STM is coded acoustically and lasts about 18 seconds unless it is rehearsed. If we rehearse it long enough (maintenance rehearsal) it passes into long term memory this is known as elaborative rehearsal.
• What is LTM? How does memory pass through it? How do we recall information from LTM?

  LTM is the potentially permanent memory store for information that has been rehearsed for a prolonged time. LTM is coded semantically and psychologists believe it's duration is up to a life time. Memories are theoretically only temporarily inaccessible due to interference and retrieval failure. According to the MSM, when we want to recall information from LTM it has to be transferred back into STM by a process called retrieval.
• AO3: Strength- List the research support for the MSM?

  There is a huge amount of evidence to support the separation of LTM and STM:

  Baddeley (1966) found that we tend to mix up words that sound similar (acoustically similar) when we're using our STM whereas we mix up words that have similar meanings (semantically similar) when we're using our LTM. Further support comes from studies of capacity and duration e.g Jacobs found the capacity of STM to be between 5-9 items by using the digit span technique whereas capacity of LTM has been found to be unlimited. Peterson and Peterson have found that STM has a duration of 18 seconds by testing participants with the recall of a trigram- using distractor tasks whereas duration of LTM by Bahrick found that participants could still recognise the peers in their high school year books, after 48 years! This shows LTM can last up to a lifetime. These studies all therefore clearly show that STM are separate and independent memory stores, as claimed by the MSM.
• AO3: Counterpoint, what is a limitation to the research support for MSM?

  Many of the research support studies for the separation of STM and LTM used digits, letters and sometimes even words in their studies to test memory. They even used consonant syllables that have no meaning. The memories we form in every day life however, are much different and are related to all sorts of useful things- people's faces, their names, facts, places etc. Many of the studies that support MSM used none of these materials meaning that the MSM may not be a valid model of how memory works in everyday lives where we have to remember much more meaningful info.
• AO3: Strength- describe the case study that has shown that the assumptions about the linear nature of the MSM are valid?


  Case studies like those of HM. HM had his hippocampus removed in an attempt to cure his epilepsy and as a result he suffered from anterograde amnesia. He was able to function in his STM loop of about 30 seconds, and had most of his memories prior to the operation intact. However, he was unable to create new long term memories as the process by which information was transferred from one store to another was now broken. This supports the unitary nature of MSM and the linear nature of committing memory to LTM.
• AO3: Weakness- describe the case study that refutes the MSM?

  The case of patient KF who was injured in a motor cycle accident. Following his accident, KF could recall information from his LTM but had issues with his STM: he was was able to remember visual images however he couldn't remember sounds (acoustic information). This suggests that there are at least two components within STM, one component for visual information and one for acoustic, which suggests that the MSM may provide an oversimplified account of STM.
• Who realised that the MSM view of LTM was too simplistic and inflexible? What did he propose instead?

  Endel Tulving (1985). Tulving proposed that there are infact three LTM stores, containing quite different types of information.
• What were the three LTM stores Tulving proposed?

  Episodic memory, semantic memory and procedural memory.
• Describe episodic memory?


  A LTM store for personal events, e.g the breakfast you ate this morning, and so has been likened to a diary. Includes memories of where and when events occurred (so is time stamped) and of the people, places and behaviours involved. Memories from this store have to be retrieved consciously with effort.
• Describe semantic memory?


  A LTM store for our knowledge of the world/shared knowledge so has been likened to an encyclopaedia and a dictionary. Includes facts and knowledge of what words and concepts mean. Needs to be recalled deliberately and is not 'time stamped.
• Describe procedural memory?


  A LTM store for our knowledge of how to do things (muscle memory) e.g driving a car. Includes our memories of learned skills which we can recall without much effort, eventually. They are the sorts of skills we may find difficult to explain to someone else because our ability to do them becomes automatic through practice.
• Where are each of the types of LTM located?

  Episodic: located in the hippocampus.

  Semantic: located in the temporal lobe.

  Procedural: located in the cerebellum.

  (note: the fact that there is evidence to suggest that the different types of LTM are located in different areas of the brain further supports Tulving's proposition that LTM isn't a unitary store but that there is multiple components to LTM).
• AO3: Strength- describe the evidence supporting different stores of LTM?


  The evidence from the famous case study of HM and Clive Wearing. In both men, episodic memory was severely damaged (after going under operation and from infection). However their semantic memories were left relatively unaffected as they still understood the meaning of words: E.g HM couldn't recall stroking a dog half an hour earlier yet did not need to have the concept of 'dog' explained to him. Their procedural memories were also intact: both knew how to walk and speak. Also Clive Wearing, a professional musician, new how to read and sing. This evidence supports Tulving's view that LTM is not unitary but has different memory stores within it since once was damaged but others left unaffected.
• AO3: Limitation- counterpoint, what is a limitation to studying people with brain injuries/clinical trials?


  A major limitation is the lack of control over variables in clinical studies. The brain injuries experienced by participants were usually unexpected so the researcher had no way of controlling what happened to the participants before or after the injury. The researcher had no knowledge of the individuals memory before the damage, without this it isn't easy to judge exactly how much worse it is afterwards. This lack of control limits what clinical studies, like that of Clive Wearing and HM, can tell us about LTM.
• AO3: Strength- describe how understanding different types of LTM has had real world applications?

  It has allowed psychologists to help people with memory problems. For example, as people age they experience memory loss and research shows that this is mostly specific to episodic memory- it becomes harder to recall memories of personal events. As a result of this research, interventions have been designed to help improve episodic memories in older people which was proven to work: the trained participants performed better on a test of episodic memory than a control group. This shows that distinguishing between types of LTM enables specific treatments to be developed.
• Who proposed the WMM and why? What is it?

  It was proposed by Baddeley and Hitch (1974) as they thought the MSM was too simplistic, WMM is an alternative that challenges the concept of a single unitary store for STM. The WMM is a model of STM which sees information professing as an active process.
• What are the models four main components?

  The central executive, the phonological loop, the visuo-spatial sketchpad, the episodic buffer.
• Describe the role of the central executive?

  The central executive is seen as the most important component and directs attention to one of the three subsystems. It has a very limited capacity and is modality free. It's involved in decision making and problem solving.
• Describe the role of the phonological loop and what it is subdivided into?

  The phonological loop deals with auditory information temporarily (approx 2 seconds) and preserves the order in which information arrives. It is subdivided into the phonological store (words we hear) and the articulatory process (which allows maintenance rehearsal).
• Describe the role of the visuo-spatial sketchpad and what it is subdivided into?

  It stores visual and spatial information e.g if you were asked to work out how many windows were in your house you visualise it. It also has a limited capacity of 3-4 items. It is subdivided into the visual cache (stores visual data) or the inner scribe (records spatial information).
• Describe the role of the episodic buffer?

  It was added in 2000 to account for other types of information e.g musical memory and time sequencing- basically recording events that are happening. The episodic buffer links working memory to long term memory and wider cognitive processes such as perception.
• AO3: Strength- describe the research support studies the WMM has?

  It has research support studies of a dual-task performance which supports the separate existence of the visuo-spatial sketchpad. When Baddeley et als pps carried out a visual and verbal task at the same time (dual task), their performance on each was similar to when they carried out tasks separately. However when both tasks were visual, performance on both declined substantially. This is because both visual tasks compete for the same sub system (VSS) whereas there's no competition when performing a visual or verbal task together. This shows that there must be two separate subsystems, one for visual input (VSS) and one for verbal (PL).
• AO3: Strength- describe the case study support of the WMM?

  Case studies like those of patient KF, support the idea that STM isn't just a single unitary store such as the MSM may suggest, but that STM has separate visual and acoustic memory stores. Patient KF was injured in a motor cycle accident and following his accident he could still recall information from his LTM yet had issues with his STM. He was able to remember visual images but not sounds. For instance, his immediate recall of letters was better when he read them (visual) compared to when they were read to him (acoustic). KFs phonological loop was damaged but his visuo-spatial sketchpad was intact. Thus supporting the existence of separate visual and acoustic stores.
• AO3: Limitation, describe how there is a lack of clarity over the nature of the central executive?

  Baddeley (2003) recognised himself that there is a lack of clarity over the nature of the central executive when he said, 'the central executive is the most important but the least understood component of working memory.' The CE needs to be more clearly specified rather than just being simply 'attention.' For example, some psychologists believe that the CE may even exist of separate subcomponents. This means that the central executive is an unsatisfactory component which challenges the integrity of the WMM.