Memory Flashcards
Key study for coding in STM and LTM
Baddeley
Procedure of Baddeleys study
Four groups given different lists to remember (acoustically similar/dissimilar and semantically similar/dissimilar).
Participants asked to recall the words in the correct order. Some were required to recall immediately (STM) others 20 minutes later (LTM)
What does acoustically mean
Refers to sounds or the sense of hearing
What does semantically mean
The meaning of something
Findings is Baddeleys study
Acoustically similar words remembered worst for STM, semantic remembered worst for LTM
Conclusions from Baddeleys study
Suggests that information is coded acoustically in STM and semantically in LTM
Limitation of Baddeleys study
Used artificial stimuli rather than meaningful material. The words used had no personal meaning to the participants. Means we should be cautious about generalising the findings to different kinds of memory tasks. For example when processing more meaningful information people may use semantic encoding even for STM tasks
Study for the capacity of STM
Jacobs
Procedures of Jacobs study
Developed the digit span technique (refers to digits/ letters being read one at a time).
Researcher gives an amount of digits and the participants has to recall these in the correct order. If this is correct the research reads out more digits until the participant can’t recall the order correctly. This determine digit span
Findings in Jacobs study
Mean span for digits was 9.3 and mean span for letters was 7.3
Limitation of Jacobs study
It was conducted a long time ago and lacked adequate control of extraneous variables. Some participants may have been distracted so didn’t perform as well making the result not valid because there were confounding variables that were not controlled. However the results of this study have been confirmed in other research supporting the validity
Key study for the capacity of LTM
Miller
Procedure of Millers study
Miller reviewed several studies on memory which tested the amount of info we receive, process and remember in our immediate memory.
He made observations of everyday practice and realised things come in sevens : 7 days of the week, 7 deadly sins etc
Findings of Millers study
Suggests the span (or capacity) of STM is about 7 plus or minus two.
Chunking is also used to increase capacity. He realised people can recall 5 words as well as 5 letters.
What is chunking
Grouping sets of digits or letters into meaningful units or chunks
What is capacity
The amount of information that can be held in a memory store
Limitation of Millers study
Miller may have overestimated the capacity of STM. Cowan rconckuded that the capacity of STM was only about four chunks suggesting the lower end of Millers estimate is more appropriate than 7.
What is a digit span
Way of measuring the capacity of short term memory in terms of the maximum number of digits that can be recalled in the correct order
Key study for the duration of STM
Peterson and a Peterson
Procedure of the Peterson study
24 undergraduate students were given a consonant syllable to remember and a three digit number. Students then asked to count backwards from three digit number until told to stop. This was to prevent any rehearsal of the syllable. On each trial they are told to stop after a different amount of time (3,6,9,12 seconds etc) this is called retention interval
What is a consonant syllable
Three letter chunks with no vowels, also called a trigram
Findings of the Peterson study
After three seconds recall was about 80%. Recall after 18 seconds was about 3%.
Conclusions of the Peterson study
STM may have a very short duration (of less than 18 seconds) if maintenance rehearsal is prevented
Limitation of the Peterson study
Stimulus material was artificial. Does not reflect real life memory activity where what we are trying to remember is meaningful. I he study lacked ecological validity. However we do sometimes try to remember fairly meaningless things like phone numbers so the study isn’t totally irrelevant
What is an extraneous variable
Any variable other than the independent one that may affect the dependant variable if it’s not controlled
What is a confounding variable
Any variable that may have affected the DV so we cannot be sure if the true source of changes to the DV
Key study for the duration of LTM
Bahrick
Procedure of Bahricks study
Nearly 400 participants aged 17-74 from America.
Years books used from the participants and the participants had to recognise faces and provide their names or do free recall of names without visual aid.
Findings of Bahricks study
Face recognition after 48 years = 90%
Free recall after 48 years = 30%.
Conclusions from Bahricks study
Long term entities can last a very long time but may need cues in order to be accessed
Limitation of Bahricks study
Rehearsal may explain the results. Some participants may look st heir yearbooks regularly and that’s why their recognition and recall was so good. In this case, rehearsal is an extraneous variable. This means that some results may not be due to LTm
Strength of Bahricks study
High external validity. Real life memories were studies. When lab studies were done with meaningless pictures to be remembered recall rates were lower. The downside of real life research is that confounding variables are not controlled such as the fact the participants may have looked at the year book photos over the years.
Who devised the multi-store model of memory
Atkinson and Shiffrin
What does the MSM describe
How information moves through the memory system. The model suggest that memory is made of three stores linked by processing.
Sensory register, STM and LTM.
Describes how info is transferred from one store to another, how it is remembered and how it is forgotten
Simplified version of how the MSM works
Environmental stimuli -> sensory memory (attention) -> short term memory (rehearsal) -> long term memory (retrieval) -> short term memory again
How many stores in the sensory registers
Several, ind for each of our senses
Duration, capacity and coding of material in the sensory register
Less than half a second
Has high capacity
Coding is related to each sense
Duration, capacity and coding of the STM in the MSM
Limited capacity - between 5 and 9 items
Coded acoustically
Duration is about 30 seconds unless rehearsed
When does maintenance rehearsal occur
When we repeat material to ourselves over and over we can keep this information in STM as long as we rehearse it and if rehearsed enough it passes to the LTM
Capacity, duration and coding for LTM in the MSM
Unlimited capacity
Unlimited duration
Coding is semantic usually
What is retrieval
Recall of information previously stored in memory
Strength of the MSM
Supported by research that shows STM and LTM are different. Baddeleys study shows that coding in STM is mainly acoustic and in the LTM it is mainly semantic. Supports the MSMs view that these two memory stores are separate and independent
Limitation of the MSM (more than one store for STM)
Case studies show that STM isn’t a unitary store like MSM claims. Patient KF had amnesia and it was found KFs short term memory for digits was very poor when they were read out to him but when he read them himself it was much better. Suggests there’s more than one short term store to process visual information and one to process auditory. Working memory model is better able to account for the case of KFs
Limitation for MSM (oversimplifies LTM)
Oversimplifies the LTM. Lots of research evidence that LTM is not unitary. We have one long term memory store for our memories of fact and we have different one for memories of riding a bike. The MSM does not reflect these different types of LTM which is a problem.
What is episodic memory
Stores events from our lives. Like the visits to the dentist, psychology class, the breakfast you ate and so on
Elements of episodic memory
- time stamped (you remember when they happened)
- involve several elements (people, places, objects)
- you make a conscious effect to recall them
What is semantic memory
Knowledge of the world. The meaning of words and the taste of an orange.
Elements of semantic memory
- not time stamped. We don’t remember when we first learned about some facts.
- it’s less personal and more about shared knowledge
What is procedural memory
Memory for actions and skills. Like driving a car.
Elements of procedural memories
- recall without much effort
- can recall without conscious awareness
Strength of the episodic memory store
Supported by case study evidence. Case of HM and Clive Wearing both men had great difficulty recalling events that had happened to them as a consequence of amnesia. Yet their semantic memories were relatively unaffected as they still understood the meaning of words. Evidence supports the view that there are different memory stores in LTM because one store can be damanged but the other store unaffected
Strength of their being different LTM stores
Brain scan studies. Tulving got their participants to perform various memory tasks while their brains were scanned using a PET scanner. Found episodic and semantic memories were recalled in different parts of the prefrontal cortex. Supports the view that there is a physical reality to the different types of LTM within the brain.
Strength of different LTM stores (real life application)
Real life applications. Episodic memories could be improved in older people who had a mild cognitive impairment. Episodic memory is the type of memory most affected by mild cognitive impairment. Highlights the benefits of being able to distinguish between different types of LTM because it ends less specific treatments to be developed.
Limitation of there being more than one store of LTM
There may only be two types of LTM rather than three. Squire argues that episodic and semantic memories are stored together in oneLTM store called declarative memory and procedural are in the non-declarative store. It is important to get the distinction between stores right because it will determine the way in which memory studies are conducted and memory is investigated.
Who worked on the working memory model
Baddeley and Hitch
What is the working memory model
Is an explanation of how one aspect of memory (STM) is organised and how t functions
Simplified version of the working memory model
Central executive can pass information to the visuospatial sketch pad, the episodic buffer, the phonological loop and these three then pass the stimuli to the long term memory
What does the WMM describe
How we temporarily store and manipulate information. E.g it is concerned with the part of the mind that is active wen working on a math problem, or playing chess or comprehending language etc
What is the central executive
The component of the WMM that Co-ordinates the activities of the three subsystems in memory. It also allocated processing resources to those activities.
Has limited or possibly no storage capacity.
What does the phonological loop consist of
Phonological store (stores the words you hear) Articulatory process (allows maintenance rehearsal)
What does the slave system of the phonological loop do
Deals with auditory information and preserves the order in which the information arrives
What does the Visio-spatial sketch pad do
Stores visual and spatial information when required in w mental space often called our ‘inner eye’