1. MODELS OF MEMORY The Multi Store Model (MSM) (Atkinson & Shiffrin, 1968)

2. MODELS OF MEMORY The IB Syllabus says: Evaluate two models or theories of one cognitive process with reference to research studies. For this section we will be evaluating TWO MODELS OF MEMORY these have been developed by cognitive psychologists to explain how memory works These are the two main models of memory we will be studying for this topic: Multi-store Model (Atkinson & Shiffrin, 1968) Levels of Processing (Craik & Lockhart, 1972)

3. Principles Demonstrated in research into Models of Memory: 1.Mental processes can and should be scientifically investigated. 2.Models of psychological functions can be proposed. 3.Cognitive processes actively organize and manipulate information that we receive - humans are not passive responders to their environment. (Soft determinism.)

4. Models & Memory Memory Definition: The mental processes involved in storing and retrieving information Model Definition: A simplified representation of some aspect of the world Essential Questions: How does our mind organize data? How do psychologists study memory?

5. Types of Memory Cognitive Psychologists generally agree that we have 3 types of memory: 1)Sensory Memory 2) Short Term Memory (STM) 3) Long Term Memory (LTM) To help use consider the differences between these types of memory, we consider their: 1) Encoding – how the information is transferred and processed in the system 2) Capacity – how much it can hold 3) Duration – how long for

6. Sensory Memory This is the first port of call for information. It gets its name from the fact that the information it receives is sensual (visual, auditory, smell, touch). The capacity is said to be vast but the duration however is only 0.25 to 2 seconds. Information from sensory memory is passed to short term memory by attention i.e. taking notice of something. (this connects to Soft Determinism – we do have some choice in what we attend to in our environment)

7. Short-term Memory Selective attention determines what information moves from sensory memory to short-term memory. STM is most often stored as sounds (acustic), especially in recalling words, but may be stored as images. STM can be transferred to LTM though rehearsal. ( we will see this in the Multi Store Model of Memory) STM is Limited capacity and duration: Works like RAM memory in computers; provides a working space. Is thought to be 7 bits in length, that is, we normally only remember 7 items (Miller, 1956) for around 30 seconds Let’s try the STM Visual Memory experiment to see if this is true. You have 30 seconds to view the items on the tray

8. Long-term Memory The knowledge we store in LTM affects our perceptions of the world, and influences what information in the environment we attend to. LTM gives the framework to which we attach new knowledge. In LTM information can be stored for extended periods of time and the limits of its capacity are not known. Information in LTM is stored in interrelated networks of schemas. top-down processing - our prior knowledge affects how we perceive sensory information.

9. Models of Memory These are the two main models of memory we will be studying for this topic: Multi-store Model (Atkinson & Shiffrin, 1968) Levels of Processing (Craik & Lockhart, 1971)

10. The Multi-store Model Atkinson & Shiffrin (1968) presented the Multi-store model of memory system proposes that: Memory consists of three separate stores and a key aspect of the model is a clear distinction between STM & LTM Their model arose from the information processing approach where memory is characterized as a flow of information through a system The system is divided into stages and information passes through the stages in a fixed sequence. There are capacity and duration limitations at each stage, and each stage may require recoding.

11. Multi-store Model Atkinson & Shiffrin (1968) Information is registered through sensory memory STM A limited amount of info is held for a short time in STM The rehearsal loop allows info to be maintained in STM for longer periods LTM Rehearsal allows info to be moved to LTM for long term storage

12. The Multi-store Model: How it works… 1.Atkinson & Shiffrin (1968) proposed that external stimuli from the environment first enter sensory memory (visual encoding) where they can be registered for very brief periods of time before decaying or being passed on to the short term store. 2.They believe that memory traces in the short term store are encoded in the form of sounds (acoustic), and without rehearsal, the memory traces become fragile and are lost within about 30 seconds. 3.Material that is rehearsed is passed on to long term store where it can remain for a lifetime, encoding in LTM is assumed to be in terms of meaning i.e. semantic

13. Miller (1956) ‘the magic number 7 plus or minus 2’ study of the capacity of STM

14. Miller got the participants to recall the following digits Miller also found that people tended to ‘chunk’ information – which one of these is easier to recall? Miller (1956) ‘the magic number 7 plus or minus 2’ study of the capacity of STM

15. Peterson and Peterson (1956) Laboratory Experiment on the duration of STM

16. Bahrick et al. (1956) experiment on the duration of LTM

17. The Serial Position Curve Ebbinghaus was the first to discover the serial position curve The serial position effect refers to the finding that recall accuracy varies as a function of an item's position within a study list. When asked to recall a list of items in any order (free recall), people tend to begin recall with the end of the list, recalling those items best (the recency effect). Among earlier list items, the first few items are recalled more frequently than the middle items (the primacy effect). On reason for this might be that the primacy effect is that the initial items presented are most effectively stored in LTM because of the greater amount of processing devoted to them. (The first list item can be rehearsed by itself; the second must be rehearsed along with the first, the third along with the first and second, and so on.) (primacy – recency effect)

18. Graph showing the serial position effect, the vertical axis shows the percentage of words recalled, the horizontal axis shows their position in the sequence

19. Glazner and Cunitz (1966) Glanzer and Cunitz (1966) conducted an experiment that demonstrated change in the outcome of the serial position curve. Aims: to examine the primacy recency effect to see if there were two separate stores of memory (STM & LTM) Procedures: PPs presented lists of words one at a time. They were asked to recall the words and could do so in any order (free recall) Experimental method used - IV - two conditions – Half PPs recalled words immediately after memorising them (immediate recall) and the other half counted backwards for 30 seconds before recalling the words (recall after distraction) Findings: They discovered that delaying recall by 30 seconds destroys the recency effect causing recall of later words to be similar to ones in the middle, however it does not influence primacy effect. Why do you think that is?

20. Conclusions: When there are too many words for them all to be remembered, the primacy effect results in the first words being recalled and the recency effect results in the last words being recalled. According to Glazner & Cunitz the primacy effect occurs because words remembered from the beginning of the list have already been stored in LTM, while the words at the end of the list are still in STM and so are also easily recalled. The distracter task reduces recency effects as it interferes with STM. The experiment offers evidence for two separate stores of memory. The graph demonstrates how delaying recall by 30 seconds with a ‘distracting’ task destroys the recency effect Glazner and Cunitz (1966)

21. Evaluation – Ecological Validity? Look back at your notes on the strengths and weaknesses of the experimental method to evaluate this study Application of Primacy and Recency effects: Lawyers scheduling the appearance of witnesses for court testimony, and managers scheduling a list of speakers at a conference, take advantage of these effects when they put speakers they wish to emphasize at the very beginning or the very end of a long list. Glazner and Cunitz (1966)

22. Summary of supporting Studies for Atkinson and Shiffrin’s Multi-storeModel Differences between short-term and long-term memory: Capacity – Miller (1956) determined that people remember 7 +/- 2 chunks of information in STM Duration – Peterson and Peterson (1959) showed memory has approximately an 18 second duration in short-term memory Encoding – Baddeley (1966) found that short-term memory relies mainly on acoustic coding, whereas long-term memory relies mainly on semantic coding Other Supporting Research Glanzer and Cunitz (1966) – study on primacy and recency effects – evidence for two separate stores of memory

23. Evaluation: Problems and Limitations of the Model However, there are problems with the model of Atkinson and Shiffrin. 1. Rehearsal does not always lead to storage. 2. If coding in the short-term memory is mainly acoustic, how do we understand language? 3. Some types of information are not amenable to rehearsal, e.g. smells and yet we remember them.

24. 4.The model is too simple and inflexible and fails to take account of factors such as the strategies people employ to remember things. 5.It also places emphasis on the amount of information that can be processed rather than the type of information 6.Some things are simply easier to remember than others, perhaps because they are more interesting, more distinctive, funnier - the MSM cannot account for this. Evaluation of the MSM model..

25. 7.It is also criticized for focusing on the structure of the memory system at the expense of adequately explaining the processes involved. For example, visual stimuli registering in sensory memory are thought to be changed to an acoustic code for access to STM. In order to translate the pattern of the letter 'M' into the sound 'em', the individual needs to access knowledge about letter shapes and sounds which is stored in LTM. This means that information from LTM must flow backwards through the system to the recoding stage prior to STM. This suggests that the flow of information through the system is interactive rather than strictly sequential as Atkinson and Shiffrin suggested. Evaluation of the MSM model..

26. 8. Atkinson and Shiffrin’s (1968) suggestion that rote rehearsal is the only means of transfer from STM into LTM has also been criticized. This criticism will be considered in more detail in the discussion of levels of processing by Craik & Lockhart (1972) which casts doubt on the assumption of Atkinson and Shiffrin that STM is a separate store with a severely limited capacity – this model highlights the influence of the depth of processing on recall Also, how does the model explain flashbulb memories? (a particularly detailed, long lasting memory of circumstances surrounding a momentous event – will be studied later in this LOA)

27. Methodology: General Evaluation of the experimental method Strengths By holding all variables constant between groups except for the IV, an experimenter may be able to establish a cause-and-effect relationship between the IV and the DV, no other research method can do this directly. The use of experiments means that researchers do not have to wait for natural events to reproduce the appropriate scenario. It allows psychologists to study behaviour that rarely occurs and cannot be studied in another way. It uses quantitative data which can be analysed using inferential statistics and once data is analysed, its possible to generalise the findings from experimental research to the rest of the population from which the sample of participants has been drawn – provided that a representative sample has been selected – but the question is how far can findings be generalised. Experimental studies can be easily replicated by other researchers, to see if they find similar results. Its easier to control confounding variables in the laboratory than in any other setting

28. Methodology: General Evaluation of the experimental method Weaknesses Loss of validity – when establishing high levels of control, the experimental situation becomes too different from real life situation. Human behaviour is extremely complex. Ecological validity is concerned with the extent to which results may be generalised to settings other than the one in which the research took place, outside the laboratory. Laboratory experiments are often very different to real life settings Demand characteristics – When participants try to make sense of the research situation and act accordingly (Orne, 1962) Participants may respond to non-verbal cues by the experimenter, and be subject to social desirability effects. Ethical issues of consent, deception and the use of animals must also be considered.