memory Flashcards
coding
- the format in which information is stored in the various memory stores
- the process of converting information from one form to another is called coding
- Baddely experiment
Baddely (not incl. results)
(1966, coding)
- gave different lists of words to four groups of participants to remember
- group 1 - acoustically similar words eg. cat, cab, can
- group 2 - acoustically dissimilar words eg. pit, few, cow
- group 3 - semantically similar words eg. great, large, big
- group 4 - semantically dissimilar words eg. good, huge, hot
Participants were shown the original words and asked to recall them in the correct order.
Baddely experiment result
When they had to recall the words immediately remembering (testing STM recall) participants performed worse with acoustically similar words.
If participant were asked to recall the word list after a time interval of 20 mins (testing LTM recall), participants did worse with the semantically similar words.
This suggests that information is coded acoustically in the STM and semantically in the LTM.
(because they were remembered the same way, it was harder to recall their order)
evaluation of the Baddely experiment
- lacks mundane realism because in real life you don’t recall a set of words with no purpose (artificial word lists)
- participant variables
capacity
- capacity is the amount of information that can be held in a memory store
- we measure the capacity of memory using ‘number of items’
- Jacobs
- Miller
Jacobs experiment
(1887 - capacity - digit span technique)
- he developed a technique to measure digit span (recalling numbers in the right order)
- the researcher gives eg. 4 digits and then the participant is asked to recall these in the correct order out loud
- if this is correct the researcher then reads out five digits and so on until the participant cannot recall the order correctly
- Jacobs found that the mean span for digits across all participants was 9.3 items and the mean span for letters was 7.3
evaluation of Jacobs experiment
- lacks mundane realism again, artificial tasks
- lacks temporal validity (1887) - research methods used were less rigorous and controlled
Miller
(1956) - main researcher for capacity, cite him
- digit span test with every letter and number but ‘7’ and ‘W’ because they have more than one syllable
- Miller found that most adults can store 7+-2 items in their STM
- He suggested that this is because it only has a certain number of “slots” in which items could be stored
- Miller also found that people can recall 5 words as well as they can recall 5 letters. They do this by chunking individual units of information (chunking can improve the capacity of STM)
chunking
- the process of grouping large amounts of information into smaller units of information to help us to retain it more easily
duration
- the length of time information can be held in memory
- Peterson and Peterson (STM)
- Bahrick (LTM)
Peterson and Peterson
(1959 - duration)
- tested 24 undergraduate students and each student took part in 8 trials
- on each trial each student was given a trigram (eg. YCG) to remember and was also given a 3 digit number
- the student was asked to count backwards in threes from their three digit number until told to stop
- this counting was intended to prevent rehearsal of the trigram
- on each trial they were told to stop after a different amount of time - the retention interval
- their findings suggested that the duration of STM is about 18 seconds unless we repeat something over and over again (rehearsal)
general duration of STM
up to 30 seconds
how many items can adults store in their STM
7 +/- 2
Bahrick
(1975)
- LTM
- studied 392 participants from Ohio between 17-74
- high school year books were obtained from the participants schools
- recall was tested via:
- photo recognition, some from the year book
- free recall test, recalling names
- participants who were tested within 15 years of graduation were about 90% accurate in photo recognition
- after 15 years this was about 60% accuracy
- after 48 years this dropped to 30% accuracy
- demonstrates that LTM may last a lifetime for certain material
evaluation of Bahrick
+ age range
+ mundane realism
- higher participant variables
- extraneous variables (reunions, communication, etc.)
what is the multi-store model for memory (MSM)
- representation of how memory works in terms of 3 stores (sensory register, STM, LTM)
- and how information is transferred from one store to another, how it is remembered and how it is forgotten
- Richard Atkinson and Richard Shiffrin (1968, 1971)
the diagram for the MSM
stimuli from environment —>sensory register (coding=modality specific)
SR–>memory decay
SR–attention–> STM —rehearsal–> LTM —retrieval—> STM
STM—->memory decay (duration=up to 30secs)
STM —->memory displacement (7+/-2 items)
sensory register: capacity, duration, coding
- coding is modality specific
- The capacity of sensory registers is huge (millions of receptors)
- information lasts for a very short time (less than half a second).
- Very little of what goes into the sensory register passes further into the memory system. But it will if you pay attention to it. So the key process is attention.
maintenance rehearsal (MSM)
Maintenance rehearsal occurs when we repeat (rehearse) material to ourselves over and over again. We can keep the information in our STMs as long as we rehearse it. If we rehearse it long enough, it passes into LTM.
retrieval (MSM)
- when we want to recall material, it has to be transferred back into STM by a process called retrieval.
- According to the MSM, this is true of all our memories. None of them are recalled directly from LTM.
memory decay
- to do with duration
- from sensory register if you don’t pay attention to the information (d=up to 0.5secs)
- from STM without rehearsal (d=up to 30secs)
memory displacement
- to do with capacity
- from STM when more than 7+/-2 items are stored
modality specific
- sensory register coding
- specific to mode of information coming in
writing about the MSM
- information flows through model in a linear fashion
- MSM is a representation of memory via boxes as stores linked by processes
how would you answer: “outline the multi-store model of memory [6 marks]”
- can draw it as long as you say the points too
- CAN ONLY DRAW for an ‘outline’ question that is 6 marks or less
MSM supporting research
- Murdock (1962)
- serial position effect
murdock (1962)
- serial position effect
- recall of the first and last words are best, whereas recall for the middle is poor
- this is because the first words have been transferred into the LTM because they have been rehearsed
- the last words are still being rehearsed in the STM
- the words in the middle are less well recalled because you were too busy rehearsing the first ones to remember them well
evaluation of Murdock’s research
- could be confounding variables (chunking, etc) and demand characteristics
- artificial word lists so low mundane realism
evaluation of the MSM for memory
- model is easy to understand and research
- model is reductionist, may be over-simplified
- supporting research (Murdock, Baddely, Bahrick, etc.)
- there may be more than one type of STM (Shallice and Warrington)
- failure to acknowledge more than one type of rehearsal (Craik and Watkins)
Shallice and Warrington
They studied a patient with amnesia known as KF and found that KF’s memory for digits was poor when they read them out lout to him but his recall was much better when he was able to read the digits to himself.
craik and watkins
found that what it is important to remember information is the type of rehearsal conducted. They found two types of rehearsal: maintenance rehearsal which maintains the information within the STM and elaborative rehearsal which is needed for long term storage.
‘MSM is too simple…’
‘MSM is too simple and inflexible to explain human memory.’ - Tulving, (1985)
Tulving
‘MSM is too simple and inflexible to explain human memory.’ - (1985)
Proposed 3 long-term memory stores, contain different types of information:
Episodic
Semantic
Procedural
the types of long-term memory stores according to Tulving
Episodic
Semantic
Procedural
episodic memory
- ability to recall events (episodes) from our lives
- like a diary, a record of daily happenings
- complex: they are ‘time-stamped’ and include several elements such as people, places, objects, and behaviours - all of which are interwoven to produce one memory
- have to make a conscious effort to recall these memories, you may be able to do so quickly but you will be aware that you are searching for that memory
eg. your friends’ wedding, your first day of school
semantic memory
- knowledge of the world (facts in the broadest sense, concepts, words, etc)
- like a combination of an encyclopedia and a dictionary
- not time-stamped, we don’t usually remember when we learned about the Eiffel tower for example
- less personal and more about the facts we all share
- constantly being added to
- usually need to be recalled deliberately
eg. your address, where the Eiffel tower is
procedural memory
- memory for actions, or skills, basically how we do things
- can recall these without conscious awareness or much effort
- eg. driving a car - our ability to do this (eventually) depends on procedural memory and we can change gear without recalling how
- might find these skills hard to explain to someone else as it requires recall and if you try to describe what you are doing as you do it, you may find the task becomes difficult
eg. how to ride a bike, how to juggle
memory for recalling events
episodic memory
memory for knowledge of the world
semantic memory
memory for actions/skills
procedural memory
evaluation points for types of long term memory
- supporting research (Clive Wearing and Henry Molaison case studies)
- conflicting neuroimaging evidence (Buckner and Petersen 1996 vs Tulving et al. 1994)
- allows psychologists to help people with memory problems, practical applications, Sylvie Belleville et al. (2006)
supporting research for long term memory
the case of Clive Wearing
- intact procedural memory (can still play the piano brilliantly after being a world-class musician)
- episodic memory is damaged so can’t remember events like a conversation
- less than 30s memory
- semantic memory is relatively intact, doesn’t need the concept of ‘doctor’ explained to him
problems with clive wearing research
- not generalisable (he has an atypical memory), reduces validity of types of LTM
- can’t compare to before the injury
buckner and petersen
(1996)
- reviewed evidence regarding the location of semantic and episodic memory
- concluded that semantic memory is located in the left side of the prefrontal cortex and episodic memory on the right