Memory P1 Flashcards
what is meant by coding?
it is the format in which information is stored in various memory stores
what is meant by capacity?
the amount of information that can be held in a memory store
what is meant by duration?
the length of time information can be held in the memory
What is meant by short-term memory?
the limited capacity memory store
coding is mainly acoustic, capacity of 5-9 items, duration is about 18s
what is meant by long-term memory store?
it is the permanent memory store
coding is mainly semantic, unlimited capacity and can store memories for up to a lifetime
What is meant by acoustic?
the way a word sounds, e.g. cat,cab
What is meant by semantic?
the meaning of the words e.g. large, huge, big
Research into coding - Baddeley 1966, acoustic & semantic
he gave different lists of words to four groups of participants to remember:
-Grp 1 acoustically similar
-Grp 2 acoustically dissimilar
-Grp 3 semantically similar
-Grp 4 semantically dissimilar
found that immediate recall was worse with with acoustically similar words, STM is acoustic
recall after 20 mins, worse with semantically similar words, LTM is semantic.
suggest info is coded acoustically in STM and semantically in LTM
Research into capacity, Jacobs 1887 testing digit span
researcher reads four digits and increases until ppt can’t recall the order properly
final number = digit span
- on average ppt’s could repeat back 9.3 numbers & 7.3 letters in the correct order immediately after they were presented.
Research into capacity, Miller 1956, magic number 7+/-2
miller observed everyday practice, noted things come in sevens - notes of musical scale, days of the week, deadly sins etc.
miller thought span of STM is about 7 items + or minus 2 (5-9)
increased by chunking
What is chunking?
grouping sets of digits/letters into meaningful units to remember more pieces of info
Research into Duration of STM, Peterson & Peterson 1959, consonant syllables
24 students given a consonant syllable (YCG) to recall and a 3 digit number to count backwards from
the retention interval was varied: 3,6,9,12,15,18 seconds
found that after 3 seconds average recall was about 80%, after 18 seconds it was 3%.
this shows that STM duration w/o rehearsal is up to 18 seconds.
Research into LTM duration, Bahrick 1975 yearbook photos
studied 392 americans aged 17-74
1. recognition test - 50 photos from yearbook, had to name them
2. free recall test - ppt’s listed names of their graduating class
they found for recognition 90% accurate after 15 years and 70% accurate after 48 years. for the free recall test - 60% recall after 15 years and 30% after 48 years. This shows that LTM may last up to a lifetime for some material
A strength of Baddeley’s study is that it identified two memory stores.
Later research showed that there are exceptions to Baddeley’s findings. But STM is mostly acoustic and LTM is mostly semantic. -> this led to the development of the multi-store model
A limit of Baddeley’s study is that it used artificial stimuli.
The words used had no personal meaning to the ppt’s so tells us little about coding for everyday memory tasks. When processing more meaningful information, people use semantic coding even for STM. This means the findings of this study have limited application.
A strength of Jacobs’ study is that it has been replicated.
this is an old study and may have lacked adequate controls (confounding variables e.g. ppt’s being distracted. Despite this, Jacobs’ findings have been confirmed in later controlled studies e.g. Bopp 7& Verhaeghen 2005. This shows that Jacob’s study is a valid measure of STM digit span.
A limit for millers study is it may overestimate STM capacity.
for example, Cowan 2001 reviewed other research. He concluded that the capacity of STM was only about 4 +/-1 chunks. This suggests that the lower end of miller’s estimate, 5 items, is more appropriate than 7 items.
A limit of Peterson & Peterson’s study is the use of meaningless stimuli.
We sometimes try to recall meaningless things so the study isn’t completely irrelevant. But recall of consonant syllables doesn’t reflect meaningful everyday memory tasks. Therefore the study lacked external validity.
A strength of Bahrick’s study is that it has high external validity.
Everyday meaningful memories e.g. of peoples faces and names, were studied. Shepard 1967 found When lab studies were done with meaningless pictures to be remembered recall rates were lower. This means that Bahrick’s findings reflect a more ‘real’ estimate of the duration of LTM.
What is the multi-store model (Shiffrin &Atkinson) ?
describes how info flows through the memory system.
a representation of how memory works in terms of three stores called the sensory register, STM and LTM. describes how info is transferred from one store to another, what makes memories last and some disappear.
What is meant by the sensory register?
the memory stores for each of our five senses such as vision (iconic) and hearing (echoic). coding in iconic SR is visual and in echoic SR is acoustic.
Massive capacity
info lasts for half a second
all stimuli from the environment pass into SR,
How does the sensory register effect coding, capacity and duration?
coding - modality specific, depends on the sense
duration - very brief less than 0.5s
capacity - high e.g. over one hundred million cells in one eye each storing data
how does the info transfer from SR to STM?
IF ATTENTION IS PAID TO THE INFORMATION - KEY PROCESS
Describe elements of STM refering to msm
a limited capacity store of temporary duration
coding - acoustic
duration - 18 seconds, unless info is rehearsed
capacity - 7+/-2 items before some forgetting occurs, cowan argues for 5
How does info transfer from STM to LTM?
when we repeat material to ourselves, this is maintenance rehearsal - stays in STM, if we rehearse long enough it passes into LTM - prolonged rehearsal
describe elements in LTM REFER TO MSM
a permanent memory store
coding - mostly semantic
duration - potentially up to a lifetime
capacity - potentially unlimited
How is information retrieved from LTM?
when we want to recall info stored in LTM it has to be transferred back to STM to be recalled
a strength for MSM is research support showing STM & LTM are different.
Baddeley 1966 found that we tend to mix up words that sound similar when using our STMs, so STM coding is acoustic. But we mix up words that have similar meanings when we use our LTMs, shows LTM coding is semantic.
-> This supports the MSM’s view that these two memory stores are separate and independent.
A counterpoint for strength of MSM
Despite such apparent support, the studies tend not to use everyday information e.g. faces and names. They use digits/letters or meaningless consonant syllables. Therefore the MSM may not be a valid model of how memory works in everyday life where memory tends to involve meaningful information.
A limit of MSM, is evidence suggesting there is more than one STM store.
In Shallice & Warrington 1970, KF had amnesia, STM recall for digits was poor when he heard them, but much better when he read them. Other studies confirm there may also be a separate STM store for non-verbal sounds e.g. noises. Therefore the MSM is wrong to claim there is just one STM store processing different types of information.
A limit of MSM is prolonged rehearsal is not needed for STM-LTM transfer
Craik & Watkins 1973 argued there are two types of rehearsal called maintenance and elaborative. Maintenance is the one described in the MSM but elaborative rehearsal is needed for long-term storage. This occurs when you link information to your existing knowledge, or think about it’s meaning. This suggests that the MSM doesn’t fully explain how long-term storage is achieved.
What is the case of HM?
-relate to MSM model
had brain surgery to relieve his epilepsy, his hippocampus was removed from both hemispheres
-when memory assessed in 1955, he thought it was 1953 & he was 27(he was 31)
-couldn’t form new long term memories
-performed well in tests of immediate memory span, a measure of STM.
what is the study of Clive wearing?
- has a severe form of amnesia, damaged hippocampus
- before was a world-class musician, he could still play the piano brilliantly & conduct a choir, but couldn’t remember his musical education
- he could remember his second wife’s name and greets her when they meet, believing he hasn’t seen her in years
what is the study of KF?
in shallice & warringtons 1970 study
- he was hit by a motorcycle
- poor STM for auditiory info, but could process visual info normally.
- immediate recall of letters & digits was better than when he read them over them being read to him
the three types of long term memory are?
Episodic
Semantic
Procedural
what is meant by episodic memory?
- stores events from our lives, linked to a diary of daily linked personal experiences
- memories are complex, time stamped - remember when they happened and how they relate in time,
- several elements
- make a conscious effort to recall them
A strength of types of long term memory is case study evidence of different types of LTM
Clinical studies of amnesia, HM & Clive wearing, showed both had difficulty recalling events that had happened to them in their pasts. But their semantic memories were relatively unaffected e.g. HM didn’t need the concept of ‘dog’ explained to him. Procedural memories were also intact as clive could still play the piano & conduct a choir. This supports the view that there are different memory stores in LTM because one store can be damaged but other stores are unaffected.
A counterpoint to the strength of episodic memory
researchers lack control in clinical case studies - they don’t know anything about the person’s memory before the brain damage. Therefore clinical studies are limited in what they can tell us about different types of LTM.
what is meant by semantic memory?
stores our knowledge of the world
- a combination of an encyclopaedia and a dictionary.
e.g. includes memories of how an orange tastes
not time stamped
less personal than episodic more about facts/knowledge we all share
A limit for types of long term memory is conflicting finding about types of LTM and brain nerves.
Buckner & Peterson 1996
reviewed research findings and concluded that semantic memory is located in the left prefrontal cortex and episodic with the right prefrontal cortex. But other studies from Tulving 1994 have found that semantic memory was associated with the right prefrontal cortex and the reverse for episodic memory. This challenges any neurophysiological evidence to support types of memory as there is poor agreement on where each type might be located.
What is meant by procedural memory?
stores memories for actions & skills -memories of how we do things e.g. how to drive a car recall occurs w/o awareness/effort -they become automatic with practice -> explaining step by step procedure of changing gears is hard because you do it w/o conscious recall
A strength for types of long term memory is helping people with memory problems.
Memory loss in old age is specific to episodic memory, it is harder to recall memories of recent experiences although past episodic memories are intact. Belleville 2006 devised an intervention for older people targeting episodic memory, which improved their memory compared to a control group. This shows that distinguishing between types of LTM enables specific treatments to be developed.
eval extra for types of long term semantic & episodic the same or different?
More recently tulving 2002 has said episodic memory is a ‘specialised subcategory’ of semantic, an intact semantic memory can function w a damaged episodic but not vice versa. However, Hodges and Patterson 2007 found that some patients with Alzheimer’s disease can form new episodic memories but not semantic ones. Therefore episodic and semantic memories are closely related but ultimately different forms of LTM.
what does the working memory model represent?
the STM store
suggests STM is a dynamic processor of different types of info using sub units co-ordinated by a central decision-making system.
concerned with ‘mental space’ that is active when temp storing and manipulating info
the Baddeley & Hitch 1974 working memory model
concerned with ‘mental space’ that is active when for example working on arithmetic problem or comprehending language.
what is the role of the central executive in the wmm?
the central executive allocates subsystems
- a supervisory role where it monitors incoming data, directs attention and allocates subsystems to tasks
- limited storage capacity
