Types and features of memory Flashcards
Define coding.
The format in which information is stored in the various memory stores.
What is the coding for STM?
Acoustic (sound of words).
What is the coding for LTM?
Semantic (meaning of words).
Who conducted research into the coding of STM and LTM?
When?
Baddeley 1966.
Explain Baddeley’s experiment.
4 groups given a list of words to remember:
- acoustically similar (cat, can, cab)
- acoustically dissimilar (pit, few, cow)
- semantically similar (great, large, big)
- semantically dissimilar (good, huge, hot)
STM - asked to recall immediately
LTM - asked to recall after an interval of 20 minutes.
What were the findings of Baddeleys research?
STM - tended to worse with acoustically similar words.
LTM - tended to do worse on semantically similar words.
State a criticism of Baddeley’s research into the coding of STM and LTM.
Artificial stimuli - rather than meaningful material so limited application to real life scenarios so we should be cautious when generalising.
Define capacity.
The amount of information that can be held in the various memory stores.
What 2 psychologists conducted research into the capacity of the STM?
When?
Jacobs - 1887
Miller - 1956
Describe Jacob’s research.
Digit span
- Participants given 4 digits to remember and continued to increase the number until the participant couldn’t recall the order correctly.
- Mean span for digits 9.3
- Mean span for letters 7.3
Describe Miller’s research.
- Made observations of everyday practice and noted that things came in 7’s - 7 days of the week.
- Suggests capacity of the STM is 7+-2
- Noted that people could recall 5 words as well as 5 letters - chunking
State 2 criticisms of the research into the capacity of the STM.
Lacks validity - conducted a long time ago when experiments lacked adequate control and could’ve been affected by confounding varies (participants could’ve become distracted).
Miller may have overestimated the capacity of STM - 5 items more appropriate than 7.
What is the capacity of the STM?
7+-2
What is the capacity of the LTM?
Infinite/limitless
Define duration.
The length of time information can be stored in a memory store.
Who conducted research into the duration of the STM?
When?
Peterson and Peterson - 1959
Describe Peterson and Peterson’s research.
- Tested 24 undergraduate students.
- Each took part in 8 trials.
- On each trial the student was given a consonant syllable with no meaning (e.g. YCG) - a trigram, and a 3 digit number.
- The student was then asked to count backwards from that digit number until told to stop in order to prevent mental rehearsal.
- On each trial they were told to stop after a different amount of time - 3, 6, 9, 12, 15 ad 18 seconds (retention interval).
What were the findings of Peterson and Peterson’s study?
That the STM has a duration of 18 seconds.
Who conducted research into the duration of the LTM?
When?
Bahrick et al. - 1975
Describe Bahrick’s research.
- Studied 392 participants aged 17-74.
- High school year books obtained - recall tested:
1. photo recognition test
2. free recall
What were the findings in Bahrick’s research?
- Participants tested within 15 years had 90% accurate photo recognition.
- Participants tested after 48 years, recall had declined to 70%.
- Free recall for within 15 years = 60%.
- Free recall for after 48 years = 30%.
State a criticism of Peterson and Peterson’s research.
Artificial/meaningless stimuli - doesn’t reflect most real-life memory activities and therefore lacks external validity.
State a positive of Bahrick’s research.
High external validity - real life meaningful memories however there may be confounding variables that can’t be controlled.
Name 3 types of LTM.
Episodic
Semantic
Procedural
What is episodic LTM?
- For personal events, e.g. when you last went to the dentist.
- ‘Time-stamped’ - remember when they happened.
- Several elements all interwoven to create a single memory.
- Have to consciously retrieve them.
What is semantic LTM?
- Knowledge of the world.
- Knowledge of words and concepts, e.g. what an orange tastes like or applying to university.
- Constantly being added to.
- Not ‘time-stamped’.
What is procedural LTM?
- Knowledge of how to do things (actions/skills).
- Memory of learned skills, e.g. riding a bike.
- Trying to explain them makes the task more difficult.
- No conscious effort required to recall.
State 3 positives that support the existence of types of LTM.
- Clinical evidence - HM and Clive Wearing - epidsodic memory severely impaired due to amnesia but semantic memory relatively unaffected (e.g. still understood the meaning of words) - procedural memory also intact as they knew how to walk and speak.
- Neuroimaging evidence - brainscan studies - Tulving got participants to perform various memory tasks while their brains were scanned - episodic (recalled from right prefrontal cortex) and semantic (recalled from left prefrontal cortex).
- Real life application - training programmes for adults with mild cognitive impairments improved episodic memory recall.
State a criticism of the existence of types of LTM.
Clinical evidence - lack control as they’re case studies so are unique and lack generalisability.
