memory

• How are STM and LTM distinguished?

  STM and LTM are often distinguished in terms of their coding, capacity and duration.
• STM and LTM are often distinguished in terms of their coding, what does this refer to?

  Coding refers to the format in which information is stored in the various memory stores.

  - Information enters the brain via the senses (e.g. eyes and ears) and then is changed to another form so that it can be stored in memory. It can be stored in the form of sounds (acoustic), images (visual) or meaning (semantic)
• STM and LTM are often distinguished in terms of their capacity, what does this refer to?

  Capacity refers to the amount of information that can be held in a memory.
• STM and LTM are often distinguished in terms of their duration, what does this refer to?


  Duration refers to the length of time that information can be held in memory
• Baddely (1966) on coding in STM and LTM

  - procedure

  LABORATORY EXPERIMENT- participants were given four sets of words to learn- acoustically similar words (cat, cap, can) or dissimilar (pit, few, cow)- semantically similar (great, large, big) or dissimilar (good, huge, hot).- they were required to recall the words in the original order either immediately (testing STM) or after a 20-minute delay (testing LTM)
• Baddely (1966) on coding in STM and LTM

  - findings

  - immediate recall worse with acoustically similar words -> indicates acoustic coding in short-term memory (STM)

  - recall after 20 minutes worse with semantically similar words -> suggests semantic encoding in long-term memory (LTM)
• Why was immediate recall worse with acoustically similar words?


  STM causing acoustic confusion and becoming distracted by sounds of words thus not recalling in order
• Why was prolonged recall worse with semantically similar words?

  LTM causing semantic confusion and becoming distracted by meaning of words thus not recalling in order
• What is a strength of Baddeley's 1966 study on coding in STM and LTM?

  ✓ Showed differences between stores


  • showed differences between stores.

  • Later research showed that there are some exceptions to Baddeley's findings, e.g. types of coding.

  • However, the idea that STM uses mostly acoustic coding and LTM mostly semantic has stood the test of time.

  • This was an important step our understanding of the memory system, which led to the creation of the MSM.
• What is a strength of Baddeley's 1966 study on coding in STM and LTM?

  ✓ there is a high degree of control over extraneous variables


  • A strength of Baddeley's study is that there is a high degree of control overextraneous variables.• This allows us to see clearly that the IV (coding: semantic or acoustic) was what affected the DV (recall), improving the validity of results- This also means the experiment can be easily replicated
• What is a limitation of Baddely's 1966 study on coding in STM and LTM?

  ✘ it didn't use meaningful material.


  • A limitation of Baddeley's study is that it didn't usemeaningful material.• The words used in the study wereartificialhad no personal meaning to participants. When processing more meaningful information, people may use semantic coding even for STM.• This means that the results of this study have limited application in the real-world. We should be cautious about generalising the findings to different kinds of memory task.
• Baddeley et al. (1975)


  procedureLAB EXPERIMENTusing a dual task paradigm.-participants engaged in separate visuo-spatial sketch pad tasks - tracking a moving point of light and mentally navigating a capital 'F.
• Baddeley et al. (1975)


  results• Participants found it harder to complete two visual tasks at the same time than to complete the visual and verbal task.

  • The greater difficulty is because both visual tasks compete for the same limited resources, but when doing a verbal and visual task simultaneously, there is no competition.
• Jacobs (1887) on capacity of STM

  - procedure

  LAB EXPERIMENT• Used a digit span - researcher read four digits and increased until the participant could not recall the order correctly immediately.
• Jacobs (1887) on capacity of STM

  - findings

  • Digits = 9.3

  • Letters = 7.3
• What is a strength of Jacobson's (1887) study on capacity of STM?

  ✓ Replication of Jacob's study


  • Older studies often lackedadequate controls, e.g. , some participants' digit spans might have been underestimated because they were distracted during testing (confounding variable).• However, Jacob's findings have been confirmed and validated by other, better controlled studies since.• This suggests that Jacob's study has 'stood the test of time' and is a valid test of digit span in STM.
• Miller (1946) on capacity of STM

  - procedure

  • made observations and noted that the span of immediate memory is about 7 items.

  • For example, he noted that people can count 7 dots flashed on a screen but not many more. The same is true if you ask people to recall musical notes, words or even letters.
• Miller (1946) on capacity of STM

  - findings


  - STM span is approximately 7 items (plus or minus 2).

  recall improves with chunking - organizing data into meaningful groups.

  Example: Transforming BBCCAITVAARAC into BBC, CA, ITV, AA, RAC, which occupies only 5 memory slots.
• What is a strength of Miller's 1946 study on capacity of STM?

  ✓ it has many practical applications.


  • A strength of research into the capacity of STM is that it has manypractical applications.• Research into chunking laid the foundations for the postcode system we use in the UK today.• Baddeley discovered that if the initial letters of a postcode made up something meaningful (e.g. BS for Bristol) it made it easier to remember.• This shows how research into the capacity of STM has helped improve the efficiency of memory in a real life situation.
• Peterson and Peterson (1959) on duration of STM

  - procedure

  LABORATORY EXPERIMENT• Sample of 24 undergrad students.• Peterson and Peterson gave participants 'nonsense trigrams' (for example CKX), which they had to recall after a retention interval of varying amounts of time from 0-18 seconds.• On presentation of each trigram, they were required to verbally count backwards in threes from a specified number to prevent participants rehearsal
• Peterson and Peterson (1959) on duration of STM

  - findings & conclusion

  • After 3 seconds, 80% recalled correctly.

  • After 18 seconds, fewer than 10% of trigrams were recalled.
• Peterson and Peterson (1959) on duration of STM

  - conclusion

  • Rehearsal gotprogressively worseas the delay grew longer.• This suggests that the duration of STM is approximately 18 (to 30) seconds if rehearsal is prevented.
• What is a limitation of Peterson and Peterson's 1959 study on duration of STM?

  ✘ Use of artificial stimulus

  • A limitation of Peterson and Peterson's study is theartificial stimulus.• Recalling trigrams does not reflect most everyday memory activities where what we are trying to remember is meaningful.• On the other hand, we do sometimes try to remember fairly meaningless things, such as phone numbers, so the study is not totally irrelevant.• This means the study lackedecological validityas it may not be possible to generalise findings to real-life.
• Bahrick et al (1975) on duration of LTM

  - procedure

  FIELD EXPERIMENT to explore memory retention, graduates aged 17 to 74 from an American high school.Tasks:Photo recognition: participants selected former classmates from 50 graduation photosFree recall: Participants named classmates without visual aids.
• Bahrick et al (1975) on duration of LTM

  - findings

  (1) Photo recognition task:

  - 90% accuracy if graduated within 15 years

  - 70% accuracy if graduated within 48 years

  
  

  (2) Free recall task:

  - 60% accuracy if graduated within 15 years

  - 30% accuracy if graduated within 48 years
• Bahrick et al (1975) on duration of LTM

  - conclusion

  LTM can potentially last for years, if not a life time (shown particularly in photo recognition task)
• What is a strength of Bahrick et al's 1975 study on duration of LTM?

  ✓ field experiment, higher external validity


  • One strength of Bahrick's study is that it is afield experimentso is higher in external (ecological) validity than other memory studies.• Also, real life memories were studied (i.e. people's names and faces), thus the behaviour shown is more valid and authentic than other research which conducted with meaningless pictures or words in laboratory experiments, where recall rates were lower.• This suggests that Bahrick et al's study reflects a more 'real' estimate of the duration of LTM (high external validity).
• What is a limitation of Bahrick et al's 1975 study on duration of LTM?

  ✘ no control over confounding variables


  • A downside of real life research (field experiments) is thatconfounding variablesare not controlled, thus making it harder to conclude that the DV was only affected by the IV.• Participants may have spent further time with certain classmates / stayed in touch.• This would make recollection a lot easier as time frame since a last interaction would be reduced, reducing the validity of results gathered.
• What is the multi-store model of memory?

  - Atkinson and Shiffrin (1968)


  linear model illustrating the information flow through three memory stores (sensory store -> STM -> LTM)

  
• What is a strength of the Multi-store model of memory?

  ✓ Research support from Baddeley


  •P:Research support for the idea of LTM and STM being different and separate stores provided byBaddeley (1966)•E:In his study on coding, he gave participants one of four lists of words to remember and found that acoustically similar words were harder to recall immediately and semantically similar words were harder to recall after 20 minutes.•E:It was concluded that acoustic confusion was occurring in STM, and semantic confusion in LTM, suggesting STM codes acoustically and LTM semantically•L:This shows that the two types of memory are different from one another, as MSM suggests.
• What is a limitation of the Multi-store model of memory?

  ✘ research studies supporting the MSM use artificial materials


  P:A limitation, despite such apparent support, is that the research studies supporting the MSM use artificial materials.•E/E:In everyday life, we form memories related to all sorts of useful things(people's faces, names etc). However, many of the supporting studies for MSM didn't use these realistic materials, but rather digits, letters and sometimes words which hold no meaning.•L:This suggests that the MSM lacks external validity. Research findings may reflect how memory works with meaningless material in a lab setting, but MSM may not be an accurate/valid model of how memory works in our everyday lives, where we have to remember much more meaningful information.
• What is a limitation of the Multi-store model of memory?

  ✘ evidence from Shallice and Warrington's 1970 study, suggesting that there is more than one type of STM


  P:A limitation of the Multi-store model (MSM) is its assertion that Short-Term Memory (STM) is a singular store, contrary to evidence indicating multiple types of STM.E:Shallice and Warrington's (1970) study of KF, an amnesic patient, revealed poor STM for verbally presented digits but improved recall when digits were self-read visually.A:This is a weakness because it suggests distinct STM stores for visual and verbal information.L:The finding challenges the MSM's unitary STM concept, highlighting the need for a model like the Working Memory Model, which incorporates separate stores like the phonological loop and visuo-spatial sketchpad.
• What is a limitation of the Multi-store model of memory?

  ✘ the MSM only explains one type of rehearsal


  P: One limitation of the Multi-store model (MSM) is that it exclusively focuses on one rehearsal type.E:Craik and Watkins argued that the critical factor for memory retention is the type of rehearsal, not the quantity. They identified 2 types of rehearsalMaintenance rehearsal (verbal repetition):Keeps information in Short-Term Memory (STM).Elaborative rehearsal:Essential for long-term storage, involving linking information to existing knowledge or considering its meaning.A:This is a weakness because it highlights that the MSM fails to incorporate research findings emphasizing the pivotal role of rehearsal type in memory mechanisms.L:As a result, this lower the explanatory power of the MSM.
• Craik and Watkins


  The critical factor for memory retention is the type of rehearsal, not the quantity.Two types of rehearsal:Maintenance rehearsal (verbal repetition):Keeps information in Short-Term Memory (STM).Elaborative rehearsal:Essential for long-term storage, involving linking information to existing knowledge or considering its meaning.
• Tulving (1986) and types of long-term memory?


  Multi-store model criticized for treating LTM as a single vast store with no distinctions.

  Tulving (1986) proposes multiple types of LTM, each linked to different functions and associated with different brain areas.

  categories: episodic, semantic, procedural.
• Tulving's 1989 study on the differences in processing of episodic and semantic memories:

  - procedure

  aim - examine brain activity during semantic and episodic memory retrieval- six volunteers received radioactive gold injection (scanned using a gamma ray detector to detect its location.)- pps thought about4 semantic topics- involving general knowledge and4 episodic topics(involving personally experienced events)- involved pps thinking about a topic, gold injection after 60 seconds, and scanning 8 seconds later
• Tulving's 1989 study on the differences in processing of episodic and semantic memories:

  - results/findings

  semantic memories -> left prefrontal cortex

  episodic memories -> right prefrontal cortex
• Tulving's 1989 study on the differences in processing of episodic and semantic memories:

  - conclusions (2)

  • episodic and semantic LTMs appear to involve different brain areas and thus are separate forms of LTM

  • The fact that episodic and semantic LTMs involve different brain areas suggests a biological basis to differences in LTM
• What is a strength of Tulving (1986) and the 3 types of long-term memory?

  ✓ episodic memory is supported by case study evidence


  P:A strength of episodic memory is that it is supported by case study evidence, such as the clinical cases study of HM.E:HM had brain surgery at 27 to alleviate epilepsy, resulting in hippocampus removal and severe amnesia- demonstrated intact procedural memory by learning and retaining mirror drawing skills despite no conscious recollection of the task- episodic memory impaired as he could not recall events that had happened to himA:This is a strength because it highlights a dissociation between intact procedural memory and impaired episodic memory, showing that there are different long-term memory stores, not only different in functionality but also location within the brain.L:As a result, this increases the explanatory power of Tulving's theory.
• What is a strength of Tulving (1986) and the 3 types of long-term memory?

  ✓ real world applications


  P:one strength of Tulving's research is that it has practical applications for psychologists.E:For example, research demonstrates the potential improvement of episodic memories in older individuals with mild cognitive impairment.Comparison of a trained group with episodic memory training to a control group without training showed a significant performance boost in the trained group.L:Highlights the advantage of distinguishing between LTM types for the development of specific and effective memory-enhancing treatments.