Paper 1: Topic 2: Memory Flashcards
Duration of memory define
Length of time info stays stored in memory
Definition of capacity of memory
Maximum amount of info that memory can store
Definition of coding of memory
he way information is changed or transformed into a format that can be stored in memory
Most common forms: visual acoustic and semantic
3 types of memory store
Short term memory
Long term memory
Sensory memory/store - initial contact for stimuli
Capacity of Sensory memory / register
Very large
because you have to be able to take in a lot of info about all the 5 senses that all go on at once
Capacity of STM
Limited (between 7+/-2 items)
Capacity of LTM
Potentially unlimited capacity
How is STM capacity assessed and who studied it
Measured by the digit span task
Jacob’s (1887) was the first to use digit span task
found the average span for numbers to be 9.3 items
For letters the average decreased to 7.3 items
George miller (1956) reviewed psychological research and concluded that ‘the magic number’ is 7+/-2
He found: We’re good at remembering between 5-9 items and people could recall around 7 dots, letters, musical notes
Argued that our capacity can be increased if we chunk items together
8/16 marker hasn’t come up before:
Limitations of Millers research into capacity of STM
P: Miller may have overestimated the capacity
Eg: more resent research by Cowan (2001) concluded capacity is closer to 4 chunks rather than 7+/-2
L: So millers results lack temporal validity
P: he didn’t specify the size of the chunk
Eg: Simon (1974) concluded people have smaller STM capacity with larger chunks
L: Although both researchers conclude that STM capacity is limited
8/16 marker hasn’t come up before:
Limitation into the research of STM capacity
P: capacity is not the same for everyone, individual differences affect results
Eg: Jacob’s found digit span increased with age
8 year olds remembered 6.6 digits
19 year olds remembered 8.6 digits
Ex: So capacity increases with age
L: capacity can’t be generalised
Duration of memory in sensory store
Very short duration, typically less than a second
iconic memory lasts about 0.5 seconds
echoic memory lasts about 3-4 seconds
Duration of STM
Approx 18-30 seconds without rehearsal
Duration of LTM
Potentially lasts infinitely
Peterson and Petersons 1959 procedure and findings to investigate duration of STM
8 trials
24 undergraduate students were given a consonant trigram and 3 digit number
Asked to recall consonant trigram after intervals of 3,6,9,12,18 seconds
P’s were asked to count backwards aloud from their 3 digit number to prevent rehearsal
Findings:
as retention interval increased, accuracy of recall decreased.
3 seconds – 80% successful recall
9 secs – 20%
18 secs – less than 10%
Conclusion: STM has a limited duration of around 18 seconds when active rehearsal is prevented.
Bahricks procedure and findings on investigating the duration of LTM
P’s: 392, US, aged 17-74
Procedure: test photo recognition (recall names of students from 50 photos) and free name recall (asked to list the names they could remember from their graduating class) from p’s high school yearbook
Photo recognition: p’s tested within 15 years of graduation were 90% accurate, after 48 years recall declined to 70%
Free recall: sfter 15 years 60% accurate, after 48 years 30% accurate
Conclusion: suggests that duration of LTM can last a very long time
8/16 marker hasn’t come up before:
Limitations of Peterson and Petersons research into STM duration
P: May have not been measuring trace decay but instead displacement so low construct validity
Eg: ppts were asked to count backwards for, their 3 digit number to prevent rehearsal which may have overwritten the trigrams.
Eg: Reitman used auditory tones instead of numbers and found duration of STM was much longer
L: methodological issues decrease the validity of results
P: results L ack ecological validity
Eg: ppts were asked to memorise and recall trigrams. Artificial task so doesn’t reflect use of stm in everyday situations like birthdays and events which are more significant than nonsense syllables
Cou: however in everyday settings we do need to remember meaningless things like phone numbers and postcodes so here the trigram task may be very representative of real life
L: caution when generalising the findings as results only have limited application to specific real-life tasks
8/16 marker hasn’t come up before:
Strenth of Bahricks research into duration of LTM
P: Barracks research has higher ecological validity than Petersons and Petersons research into duration
Eg: Procedure doesn’t lack mundane realism as it’s less artificial task then memorising trigrams
It tested p’s LTM duration by their past memories of high school classmates
C: Although there’s more confounding variables eg: some ppts may have frequently looked at their year books and others did not, meaning the internal validity of the results are compromised as the researchers may not be accurately be measuring the impact of time on LTM recall.
L: High external and low internal validity
How is info encoded in the Sensory store
sensory/modality-specific way
-encoding occurs in the way the information is received
(e.g., iconic for visual information, echoic for auditory information).
How’s info encoded in the STM
Acoustically (sound and hearing)
Hows info encoded in the LTM
Semantically (by meaning)
How did Baddeley (1966) test encoding of STM and LTM and findings
P’s were shown a list of words and asked to recall them in the correct order
Tested STM, p’s recalled words immediately after hearing them, but 20 mins after for LTM recall
STM – p’s have difficulty remembering semantically similar words when tested immediately
LTM – no difficulty remembering semantically similar words after 20 mins
Conclusion: suggests info is coded acoustically for STM and semantically for LTM
8/16 marker hasn’t come up before:
Strengths and limitations of Baddeleys research and findings into coding of memory
S: showed there’s separate memory stores
-results showed STM is encoded acoustically and LTM semantically
Allowed further research like MMS
Has temporal validity
Limitation:
There’s contradictory research evidence
Eg: Brandimote (1992) concluded p’s using visual coding in STM from a visual task
Suggests encoding isn’t always acoustic in the STM
So Baddeleys results can’t be generalised to all types of learning
Limitation:
Results lack ecological validity
Lab setting
tested the p’s recall with meaningless words. This lacks ecological validity because this isn’t a good representation of how memory is used in the real world because the words didn’t lack significance unlike people’s birthdays - artificial task
Who proposed the Multi-store memory of the mind and why was it significant
Atkinson and Shriffin (1968)
-First model of memory ever so influential to other researchers
-Suggests memory is made up of 3 distinct stores
-Linear and sequential model: info passes through the stores in order if certain conditions are met, but info can be lost in each memory store
- predicts how memories are transferred to each memory store eg: rehearsal and attention.
Word for if a memory is forgotten
Decay