Paper 1 - Memory Flashcards
Key study in coding in STM and LTM
Baddeley
Procedure of Baddeley’s study
4 groups given different lists to remember (acoustically/semantically similar/dissimilar)
Tester STM and LTM- participants asked to recall the words in the correct order. Some participants were required to recall words immediately and others had to wait for 20 minutes.
Findings and conclusions of Baddeleys study
Acoustically similar words remembered worst for STM, semantic for LTM.
Suggests that information is coded acoustically in STM and semantically in LTM
Limitation of Baddeleys study
Artificial stimuli rather than meaningful material.
The words used in the study had no meaning to the participants.
This means we should be cautious about generalising the findings to different kinds of memory task.
E.g when processing more meaningful info, people may use semantic encoding even in STM
Key study for the capacity of STM
Jacobs
Procedures of Jacobs study
Developed digit span technique - refers to digits/letters being read one at a time.
Researcher gives for example, four digits and then the participant is asked to recall these in the correct order. It this is correct, the researcher reads out five digits and so on until the participant cannot recall the order correctly - this determines the individuals digit span.
Findings of Jacobs study
Mean span for digits was 9.3.
Mean span for letters was 7.3
Limitation of Jacobs study
One limitation of this study is that it was conducted a long time ago.
Early resech often lacked adequate control of extraneous variables.
For example participants may have been distracted while they were being tested so they didn’t perform as well as they might.
This would mean the results may not be valid because there were confounding variables that were not controlled.
Procedure of Millers study
A review of other research on memory which tested the amount of information we receive, process and remember in our immediate memory.
He observed everyday practice and noted that things come in sevens: 7 days of the week, deadly sins etc
Findings of Millers study
Suggests capacity of STM is about 7 items (+/- 2)
Chunking is used to increase capacity - grouping sets of digits or letters into meaningful units or chunk
What is capacity
The amount of information that can be held in a memory store
Limitation of Millers study
He may have overestimated the capacity of STM.
COWAN reviewed other research and concluded that the capacity of STM was only about 4 chunks.
Suggests the lower end of Millers estimate is more appropriate than 7 items.
Key study into the duration of STM
Peterson and Peterson
Procedure of Peterson and Peterson’s study
24 undergraduate students were given a consonant syllable (also called trigrams) to remember and a 3-digit number.
Student asked to count back from that number until told to stop.
Counting backwards prevented any rehearsal of the consonant syllable (this would increase the students memory).
Each trial they were told to stop after different times. This is called the Retention intervals of 3,6,9,12,15 or 18.
Findings of Peterson and Peterson’s Study
After 3 seconds recall was about 80%.
Recall after 18 seconds was about 3%.
Suggests that STM May have a very short duration indeed, unless we repeat something over and over again (e.g maintainable rehearsal)
Limitation of the Peterson and Peterson study
Stimulus material was artificial.
Trying to memorise consonant syllables does not reflect most real-life memory activities where what we are trying to remember is meaningful.
Might say the study lacked ecological validity.
We do sometimes try to remember fairly meaningless things like phone numbers so it’s not totally irrelevant
Key study of duration to LTM
Bahricks
Procedure of Bahricks study
Nearly 400 participants from America aged 17-74.
Yearbooks obtained from the participants or directly from the schools. Recall tested in various ways:
a photo recognition test consisting of 50 photos, some photos were from the participants high school yearbook.
A free recall test where participants were asked to list all the names they could remember of individuals in their graduating class.
Findings of Bahricks study
Face recognition after 48 years of graduation was 90%
Free recall was less good. After 15 years, this was about 60% accurate, dropping to 30% after 48 years.
Suggests that the study suggests that long-term meteorites can last a very long time indeed, but may need cues in order to be accessed.
Limitation of Bahricks study
Rehearsal may explain the results.
Some participants might have looked at the yearbooks regularly and that’s why their recognition/recall was so good.
In this case rehearsal is acting as an extraneous variable.
This means that some results may not be due to LTM
Strength of Bahricks study
High external validity.
Real-life meaningful memories were studied.
When lab studies were done with meaningless picture to be remembered, recall rates were lower (SHEPHARD).
Downside is that confounding variables are not controlled.
What is coding
The format in which information is stored in the various memory stores
What is a consonant syllable
Three letter chunks with no vowel, also called a trigram
What is duration
The length of time information can be held in memory