memory: coding, capacity and the duration of memory Flashcards
what is memory?
the mental processes involved in registering, storing and retrieving information
what is short-term memory?
a memory store that can hold a limited amount of information for short periods
what is long-term memory?
a memory store that can hold an unlimited amount of information for long periods of time permanently
what is coding?
the format in which information is stored in the various memory stores
what are the different types of coding?
- visual coding
- acoustic coding
- semantic coding
who did research into the coding of the brain in 1966?
Alan Baddeley in 1966
what was the aim of Alan Baddeley’s study (1966)
- to find out if LTM encodes acoustically or semantically by giving participants word lists that are acoustically and semantically similar or dissimilar
- if the participants struggle to recall the word order, it suggests the LTM is confused by similarity which means this is how the LTM tends to encode
what were the operationalised IVs in Baddeley’s experiment?
- Acoustically similar world list or acoustically dissimilar
- semantically similar word list or semantically dissimilar
- performance before 15 minutes ‘forgetting’ delay and performance after (performance of interference)
what was the operationalised DV in Baddeley’s experiment?
the score on a recall test of 10 words which must be recalled in the correct order
what was the procedure of Baddeley’s experiment?
- the participants are split into four groups according to IV semantically and acoustically similar or dissimilar word lists
- in the acoustically similar condition, the participants get a list of words that sound similar but the control group get words that are all simple one syllable words that do not sound the same
- in the semantically similar condition, the participants get a list of words that share similar meaning but the control group gets words that are unconnected
- the participants in all four conditions then carry out an ‘interference test’ which involves hearing then writing down 8 numbers three times. Then they recall the words from the slideshow in order
- there are four trials and the participants improve each time they do it because the words stay the same -> only concentrate on getting the order of the words right not remembering the words themselves
- after the fourth trial, the participants get a 15 min break and perform an unrelated interference task. Then they are asked to recall the list again. This fifth and final trial is unexpected
what is a disadvantage of the sampling method Baddeley used?
- he used volunteer samples
- it is open to demand characteristics and could be biased
- by using mostly students it can be ungeneralisable and therefore lacks ecological validity.
- Use of artificial stimuli - meaningful material was not used as the word lists had no personal meaning to pps -> hard to generalise the findings to different kinds of memory tasks.
what is an advantage of the sampling method Baddeley used?
Baddeley used the independent groups design and he uses repeated measures so there’s no participant variables
what is an advantage of the experimental controls that Baddeley used?
- he uses the same words each time so it is standardised and repeatable which increases its validity
- there’s also a control group which minimises bias
- there’s a 15 minute interference test each time
what were the results of Baddeley’s research into coding?
- acoustically similar words seem to be confusing at first but soon catch up and overtake the control group
- this means the LTM is not confused by acoustic similarities
- semantically similar words do seem to be confusing and the experimental group never catches up with the control group
what were the conclusions of Baddeley’s research into coding?
- LTM encodes semantically (dissimilar)
- His earlier experiments suggest STM econdes acoustically (dissimilar)
- LTM gets confused when it has to retrieve words that are semantically similar
what does the capacity of memory mean?
the amount of information that can be held in a memory store
what is the capacity of the LTM and STM?
- the LTM has an unlimited capacity
- the STM has a limited capacity
who researched the capacity of STM and when?
Joseph Jacobs in 1887
what technique did Jacobs devise?
- the digit span technique
- a participant has to immediately recall a sequence of letters or numbers which increased by one letter or number with each trial.
what was the mean score for digits and letters across all participants in Jacobs experiment?
for digits: 9.3
for letters: 7.3
what are the advantages of Jacob’s investigation on STM?
- lab experiment so has high levels of control
- standardised procedures so easy to repeat and has high reliability
- the use of different ages can be used to generalise to all members of society (8-19 years)
what are the disadvantages of Jacob’s investigation on STM?
- lacks in mundane and ecological validity
- not generalisable to real life
- gender bias as only females were used (443 female students)
what did George Miller find in 1956 about the span of memory?
- in 1956, George Miller put forward the idea that most adults can store between 5 and 9 items in their STM
- the STM only has a certain number of ‘slots’ where items can be stored
- Miller called this magic number 7 plus/minus 2
what did George Miller find in 1956 about chunking?
- Miller noted that people can recall 5 words and letters
- they do this by chunking through grouping sets of digits/letters into units or chunks
