Unit 1: Flashcards
Multistore Model of Memory (MSM):
-created by Atkinson and Shiffrin (1968)
-information processing model of memory
-linear model: information is shown to flow through the system in one direction
-passive stores: the stores hold on to information before being passed on or lost
sensory register + info. Lost -(attention)> stm + info lost. Rehearsal (+loop) + Retrieval-> LTM
Features of each store:
-coding: the different information types/formats the brain uses to store memory
-capacity: how much information can be held by a store
-duration: how long information can be held in that store for before loss
Sensory Register:
-store is not under cognitive control like STM or LTM, sensory information coming from the senses is detected and recorded automatically
-all information found in the short term or long term memory stores were initially gathered by the sensory register
-information is passed on to STM by paying attention
-duration: 1/4 to 1/2, it cannot be retained for long
-coding: store depends on the sense organ that the information comes from
Iconic = vision, Echoic = sound, Haptic = touch, Gustatory = taste, olfactory = smell
-aka modality specific
-capacity: very large, has to contain all the sense impressions for all the senses in the moment, however only what is paid attention to is passed to the STM
Short Term Memory:
-stm receives information from the sensory register by paying attention
-STM passes info. To LTM through rehearsal, this is either maintenance rehearsal (repeating the info.) or elaboration rehearsal (linking to info. Already in LTM)
-information is passed back from LTM with retrieval, and info. Can be lost via displacement (new info.) or decay (lost over time)
-coding: information is stored acoustically (in the form of sound/spoken words)
-capacity: Miller suggested this is small, approximately 7+-2 items and this can be improved by chunking, making small sets/groups of items -> reduces the number of items overall
-duration: short, 18-30 seconds -> however, duration of info. can be extended by verbal rehearsal (rehearsal loop)
Long Term Memory:
-information stored may last permanently and LTM may be unlimited in the amount of info. It can contain
-informations comes into LTM from STM via rehearsal and in order to use information in LTM it needs to be passed back to STM via retrieval
-coding: information in stored semantically, this is in the form of “meaning”
-capacity: no limit has been found to the amount of information that can be stores in LTM, information can be lost
-duration: is potentially unlimited as recall of childhood events is normal even for the oldest people
Evidence that the STM and LTM stores are separate processes: Glanzer and Cunitz
1966
-asked participants to free recall word lists (any order)
-it was found recall was much stronger for words at the start and at the end of the the list
-these results suggest there are separate short and long term memory stores with the words first heard entering LTM and being recalled (primacy effect) and the most recent words being held by STM and being recalled (recency effect) the middle words were in STM but were displaced by later words
Sensory Register: capacity
Sperling 1960
-trained participants were presented with a three by four grid of letters (12 total)
-when presented quickly (1/20th second), then had to recall one row
-it was found that recall for a row was over 75%, this suggests that all rows were contained within the capacity of iconic store, so sensory memory is large
-when asked to recall all letters, Sperling found participants could only recall the first 4-5 letters, suggesting the letters faded from sensory memory before they could be paid attention to and passed to STM, this suggests the duration of sensory memory is <1sec
Short term memory: coding
Baddeley 1966
-gave four 10 word lists to four participants
-groups A: acoustically similar words (sound the same)
-groups B: acoustically dissimilar (word sound different)
-groups C: semantically similar (have related meaning)
-groups D: semantically dissimilar (words are unrelated)
-it was found that immediate recall was worst for list A and recall after 20 mins was worst with list D
-this suggests that the coding in STM is acoustic, as recalling list A was most difficult as the recalling similar sounds caused confusion in recall
Short term memory: capacity
Jacobs 1887
-participants were presented with lists of letters or numbers
-participants then had to recall the list
-it was found that the capacity for letters was on average around 7 items for letters and 9 for numbers, this suggests that the capacity of STM is very limited
-Miller suggested this can be improved by chunking, making smaller sets/groups of items, this reduces the total number of items overall
Short term memory: duration
Peterson and Peterson (1959)
-showed participants three letter trigrams (e.g. HFD, TKU)
-then participants had to count backwards for a few seconds to stop maintenance rehearsal (interference task)
-it was found after 18 seconds recall was less than 10%, this suggests that unless maintained information is held in STM for only a few seconds (18-30 seconds max) before it disappears
Long term memory: coding
Baddeley 1966
-gave four 10 word lists to four participants
-groups A: acoustically similar words (sound the same)
-groups B: acoustically dissimilar (word sound different)
-groups C: semantically similar (have related meaning)
-groups D: semantically dissimilar (words are unrelated)
-it was found that immediate recall was worst for list A and recall after 20 mins was worst with list D
-this suggests that the coding in LTM is semantic, as recalling list C was most difficult as the recalling similar meanings caused confusion in recall
Long term memory: capacity
Wagenaar 1986
-created a diary of over 2400 events during the course of six years including recording who, when what and where
-it was found when tested using these cues he had 75% recall of one particular critical detail after 1 years and 45% after 5 years
-and his sense of remembering the event (retention judgement) was high 80% after 5 years, this suggests the capacity of LTM is very large, potentially limitless
Long term memory: duration
Bahrick 1975
-392 participants aged 17-74 were tested for memory of old photographs and names of their school friends
-it was found recall in matching names to faces was 90% after 15 years, and still 80% for names after 48 years
-this suggests the duration of LTM is very large, potentially limitless
evidence supporting a distinction between STM and LTM: KF
Shallice and Warrington (1970), The Case of KF:
- KF, a 28 year old man who sustained brain injuries after a motorcycle accident
-he had an impaired STM, working alongside a fully functioning LTM
-intact LTM -> he was able to learn new information and recall stored information
-reduced capacity STM -> he was only able to store a couple of bits or chunks of information rather than the normal 5-9 chunks
evidence supporting a distinction between STM and LTM: HM
Milner (1966), The Case of HM:
-HM, a young man who suffered from epilepsy
-he underwent brain surgery to alleviate his epilepsy, which involved removing parts of his temporal lobes, including the hippocampus
-this operation left him with severe memory problems -> he could only recall events in his early life and was unable to recall events for about 10 years before the surgery. He could also not learn or retain new information
-however, he repeatedly read the same magazine without realising he had read it before and he was unable to recognise the psychologists who has spent long periods of time with him
-this suggests HM had a normal STM, but his LTM was detective and that it was no longer possible for him to lay down new memories in it, or if he could, he was unable to retrieve them
evidence supporting a distinction between STM and LTM: Drechman and Sahakian
1979
-administered a group of participants with a drug that blocks the action of acetylcholine in the brain, then gave them various memory tasks that tested either STM or LTM
-performance was compared with a control group
-found the experimental group performed at normal levels on the STM, but significantly more poorly on the LTM task
-suggesting STM and LTM work as a separate stored, involving different neurotransmitters
limitations of the MSM: oversimplified
-human memory is extremely complex and it is highly unlikely that such a simple model could reflect this
-for example, the model doesn’t consider the different types of things we have to remember
-while it greatly emphasises the amount of information we can handle, it disregards the nature of the information
-everyday experience tells us that some things are easier to remember than others and this can simply be because we find it more interesting, relevant, funnier, etc.
limitations of the MSM: the role of rehearsal
-there is considerable evidence that simple repetition is one of the least effective ways of passing on information
-there is also a strong evidence that long term memories can be formed without any apparent rehearsal
-Brown and Kulik (1977): they have described this type of remembering “flashbulb memory” which is where the insignificant details surrounding highly emotional and shocking events are imprinted directly into LTM without any rehearsal
Types of long term memory:
Declarative or Explicit Memory: consciously recalled (explicit) and can be put into words (declarative)
-semantic: facts, meanings, concepts and knowledge about the wolrd e.g. a bike has two wheels
-episodic: memory of experiences and specific events, e.g. the last i rode I
Non-declarative or Implicit memory: can be consciously recalled (implicit) and is difficult to be put into words (non-declarative)
-procedural: unsconscious memory of skills also known as muscle memory, e.g. skill of riding a bike
Procedural and Declarative Memory: HM Milner
1962
-Milner discovered that HM was able to learn to trace a shape using a mirror image, and retain this skills over a number of days
-however, he head no conscious recollection of ever having done mirror drawing tasks before, thus acquiring the skill
-it appears that while HM was able to use procedural memory to learn this skill, his operation had damaged his ability to use his declarative memory to consciously recollect this experience
The Working Memory Model:
-created by Baddeley and Hitch 1974 to replace the STM store of the MSM due to criticisms of the STM
-STM must be more complex than just a single unitary store that only exists to pass information on to LTM
-STM must be an active processer. holding multiple different types of information simultaneously while being worked on
Central Executive:
-“head of the model” controls attention, receives sense information and filters this before passing on to sub systems
-has slaves systems:
-phonological loop
-visuo-spatial sketchpad
-episodic buffer
-limited in capacity, (4 items) working on one type of information at a time
-but can switch attention between different inputs
Phonological Loop:
-processes auditory (sound) coded information
-primary acoustic/phonological store -> the inner ear, holding words recently heard
-articulatory loop -> the inner voice, holds information via subvocal repetition
-the PL has a limited capacity of what can be said in 2 seconds (word length effect)
Visuo-spatial Sketchpad:
-processes visual and spatially coded information, though of as the “inner eye”
-visual cache: a passive store of form and colour
-inner scribe: active store holding the relationships between objects in 3D space
Episodic Buffer:
-added to WMM in 2000, as the model needed a general store to hold and integrate information from the VSS, PL, CE and long term memory
