Lesson 1: LTM & STM Flashcards
Define Memory
Memory- process by which info encoded, stored & retrieved
Define STM
STM- stores & allows recall of info- 18-30 seconds (without rehearsal)- capacity limited
Define LTM
LTM- stores & recall info- distant past- capacity unlimited- duration lifetime
Define Capacity
Capacity- how much info held/stored
Define Coding
Coding- form in which info stored in memory
Define Duration
Duration- how long info stored/lasts
Who investigated STM duration and when?
Peterson & Peterson (1959)- STM Duration
What did Peterson & Peterson do in their study?
1) 24 pps presented with consonant trigrams e.g. ZFB
2) Asked to count backwards- ✖️ rehearsal of consonant trigram
3) Counted back for 3,6,9,12,15,18 seconds & then repeat trigram
4) Repeated using other trigrams
What were Peterson & Peterson’s results?
90% remembered after 3 seconds
20% after 9 seconds
⬇️ than 10% after 18 seconds
What did Peterson & Peterson conclude?
Info decays rapidly when ✖️ rehearsed
Initially concluded- 18 second max duration
Later concluded- 18-30 second max duration
What were the evaluation points to Peterson & Peterson’s study?
👎- trigrams unrealistic to remember… ⬇️ ecological validity- findings ✖️ apply to everyday life
👍- lab 🧪 experiment- good control of variables … can be replicated to test reliability of results
👍- confusion created among earlier trigrams … results gained from forgetting or confusion
Who investigated LTM duration and when?
Bahrick et al (1975)- LTM Duration
What did Bahrick et al do?
1) 400 🇺🇸 pps- remember former classmates
2) Identify pics, matching names to pics & recall names without picture cue
What were Bahrick et al’s results?
70% accuracy when linking names & faces
30% accuracy with free call of names
What did Bahrick et al conclude?
Suggests LTM duration of lifetime (still remembered after 30-50 years)
All info ✖️ immediately accessible- pps required cues to trigger info stored in LTM
Recall ⬆️ with cues
What were the evaluation points of Bahrick et al’s study?
👎- natural experiment- experimenter ⬇️ control of IV- confounding variables may affect results- e.g name rehearsal via classmates in touch 📞- … results possibly invalid
👍- natural experiment- meaningful material- everyday task- … ⬆️ ecological validity
👎- names of classmates- typically ⬆️ rehearsed- very specific type of info
Which 2 psychologists/studies investigated STM capacity and when?
1) Jacobs (1887)- STM Capacity
2) Miller (1956)- STM Capacity
What did Jacobs do?
1) Serial digit span technique
2) Researcher started with reading out 4 digits/letters
3) Pps had to repeat back
4) Researcher continued adding 1 more digit/letter until pps ✖️ repeat back
What were Jacob’s results?
9 digits & 7 letters recalled
As age ⬆️, capacity ⬆️- ⬆️ 🧠 capacity, development of strategies (chunking)
Digits easier to recall (only 10) BUT 26 letters
What did Jacobs conclude?
Capacity fairly limited
What were the evaluation points of Jacobs study?
👎- ✖️ ecological validity- learning lists of numbers/letters ✖️ realistic … findings ✖️ apply real life- meaningful info recalled better?
👍- study repeated (Miller)- same results found … reliability- results replicated
👎- confusion among pps- previous sequences
👎- EV controlled?- Jacob’s study- long time ago
What did Miller find?
Found capacity- 7+-2 items
Memory ⬆️ via chunking
Cowan (2001)- 4 chunks capacity- (lower end of 7+-2 items ⬆️ accurate)
What are the 3 ways info is coded?
3 ways info coded:
1) Acoustic coding- sound 🎶
2) Semantic coding- meaning
3) Visual coding- looks 👀
How is info in STM & LTM coded?
STM- encoded in mainly 🎶 form
LTM- encoded in mainly semantic form
Who investigated coding in STM & LTM and when?
Baddeley (1966)- evidence for STM & LTM coding
What did Baddeley do and find?
1) Pps shown sequence of 5 words- under 1 of following 4 conditions:
1. Acoustically similar words- immediately- least accurate for STM
2. Acoustically dissimilar words- ⬆️ accurate for STM
3. Semantically similar words- 20 min later- least accurate for LTM
4. Semantically dissimilar words- ⬆️ accurate for LTM
BUT info in STM & LTM can be stored in other forms e.g. visually 👀
What are evaluation points for Baddeleys study?
👎- ⬇️ ecological validity- words- meaningless list- semantic coding works better when info ⬆️ meaningful … limits application to real life
