Memory Flashcards
Define short term memory
Memory for events in the present or immediate past
What is long term memory?
Memory for events that have happened in the more distant past
How is LTM and STM distinguished?
Capacity, duration & coding
Define capacity
Capacity concerns how much data can be held in a memory store. STM has limited capacity whereas LTM has potentially infinite capacity
Who researched using digit span to asses the short term memory capacity.
Joseph Jacobs (1887)
What did Joseph Jacobs find the average digit span to be ?
7 for letters
9 for numbers
Who came up with the โmagic numberโ in relation to STM capacity and what is it?
George Miller (1956)
7 + or - 2 items
Who studied the duration of the STM?
Lloyd and Margaret Peterson (1959)
How did the Petersons study the duration of the STM?
24 students given a consonant syllable and a 3 digit number (e.g THX 512). They were asked to recall the consonant syllable after a retention interval during which they had to count backwards from their 3 digit number. The longer the interval the less people were able to remember.
Who studied the duration of the LTM?
Harry Bahrick
What did Bahrick do to investigate the duration of the LTM?
Tested 400 people on their memory of their classmates using a photo recognition test. The longer it was after graduation the more they were able to remember.
Evaluation of the STM?
- STM not as extensive as first thought
- size of the chunks affects how many chunks you can remember
- individual differences (capacity not the same for everyone)
- testing of the STM does not reflect everyday memory activities
- results may be due to displacement
How is information coded in the STM?
Acoustically
How is information coded in the LTM?
Semantically
Who researched coding in both the LTM and the STM?
How did they do it ?
Baddeley (1966)
Used words lists
Evaluation of coding?
- STM may not be exclusively acoustic (visual codes may be used)
- LTM may not be exclusively semantic (may be related to visual categories)
How is information encoded in the sensory register
In its original form
What is the capacity of the sensory register?
At least 12 items
What is the duration of the sensory register?
A few milliseconds
What is the multi-store model and why is it called that?
It is a model of memory that is called โmulti storeโ because it consists of three of 3 memory stores linked to each other by the processes that enable transfer of information from one store to the next
Who first described the multi store model?
Atkinson and Shiffrin (1968)
What is the sensory register?
Place where information is held at each of the senses (eyes, nose etc) and the corresponding areas of the brain
The sensory registers are constantly receiving information
What is the duration of the sensory register?
A few milliseconds
How is information passed from the sensory register to the STM?
If attention is focused on the sensory stores then data is stored in the STM
What kind of information is stored in the STM?
Information that can be stored for immediate tasks e.g remembering directions to a friends house
How can you prevent information being lost from the STM?
STM has a limited duration so Rehearsal helps to avoid decay/displacement
Define displacement
If new information enters the STM pushing out (displacing) the the original information
Why does displacement occur?
STM has a limited capacity
How is a LTM created?
A lot of repetition of the data will eventually create s LTM
Atkinson and Shiffrin proposed a relationship between rehearsal andโฆ
Strength of the LTM
The more information is reversed the better it is remembered (maintenance rehearsal)
What kind of duration and capacity does LTM have?
Potentially unlimited
Evaluation: (multi-store model of memory)Strengths of the MSM (separate stores)
- Lab studies on capacity, duration and coding support the existence of a separate long and short term memory store which is the basis for the MSM
- studies using brain scanning techniques (differences between STM and LTM)
- different areas of the brain active when completing STM/LTM tasks
Evaluation:(multi-store model of memory) Limitations of the MSM (overly simplistic)
- suggests that STM and LTM are single unitary stores
- research does not support this, there may be subsections within stores
- differ not only in capacity/ duration but also kind of memories stored
- research shows there are a number of qualitatively different types of LTM
Evaluation: (multi-store model of memory) Case studies on memory:
Clive wearing
- psychologists have also shown that different areas of the brain are involved in STM and LTM from their study of individuals with brain damage
- one case involved a man referred to as HM (Scoville and Milner 1957)
- his brain damage was caused by an operation to remove the hippocampus from both sides of his brain to reduce the severe epilepsy he had suffered
- HM personality and personality remained intact but he could not form new LTM although he could remember things from before the surgery
Evaluation: (multi-store model of memory) long term memory involves more than maintenence rehearsal
- Craik and Lokhart (1972) suggested that enduring memories are created by the processing that you do, rather than through maintenence rehersal; things that are processed more deeply are more memorable just because of the way they are processed.
- โdeepโ means doing more complicated things with the item to be remembered rather than just repeating it
- Craik and Tulving (1975) gave participants a list of nouns (e.g. โsharkโ) and asked a question that involved shallow or deep processing- asked whether a word was printed in capital letters (shallow processing) or asked whether a word was printed in capital letters or asked whether a word fitted in a sentence (deep provessing).
- the participants remembered more words in the task involving deep processing rather than shallow processing
- this โdeepโ or elaborate processing is a key process in creating long term memory
What is an alternate (extension) model of the multi store model of memory?
The working memory model
What aspect of memory does the working memory model address?
Short term memory/immediate memory
Who is the researchers concerned with the working memory model?
Baddeley & Hitch (1974)
What main thing did Baddeley and Hitch think about the STM?
STM was not just one store but a number of different stores
Why did Baddeley and Hitch think that STM consisted of a number of different stores?
- if you do two things at once (dual task performance) and they are both visual tasks you perform less well than if you do them separately
- if you do two things at the same time and one is visual and the other involves sound, then there is no interference. You do them well simultaneously as you do them separately
What did Baddeley and Hitch suggest and how does it form the basis of WMM?
- That there is one store for visual processing and a separate store for processing sounds
- this formed the basis of WMM where โslave systemsโ are organised by a central executive
Briefly describe the central executive
Monitors and coordinates all other mental functions in working memory
Explain the function of the central executive
- The function of the CE is to direct attention to particular tasks, determining at any time how the brains resources are allocated into tasks
- data arrives from the senses or form long term memory
- (the CE has a very limited capacity; in other words it canโt attend to too may things at once and has no capacity for storing data)
The phonological loop is also referred to asโฆ
The inner ear
What is the function of the phonological loop?
Codes speech sounds in working memory, typically involving maintenance rehearsal.