Memory Flashcards
Sensory store
Large capacity
0.25 to 2 seconds
Different stores for different senses
Short term memory store
7 +-2
Up to 30 seconds
Acoustically encoded
Long term memory store
Huge capacity for a life time
Semantic encoding
Peterson and Peterson
Duration of STM
Briefly showed people a trigram and asked to recall after different delays
During the delays, the participants had to count backwards in 3s to stop rehearsal
When asked to recall after 3seconds, 80% could remember
9 seconds, only 30%
Concluded that STM has a limited duration
Encoding
How we store things in memory
Baddeley 1966a
Encoding of STM
4 word lists each with 10 words
Immediate recall
Found that people correctly recalled more words when they sounded dissimilar (75% correct) compared to when they sounded similar (55%)
Similarity in meaning had little effect on the accuracy of recall
The results imply that STM involves acoustic encoding. Similar sounded words are likely to get muddled up, leading to poor recall
Episodic memory
Specific personal events
Conscious
Semantic memory
General knowledge of the worlds
Conscious
Procedural memory
Performance of actions
Unconscious
Baddeley 1966b
Encoding in LTM
Same word lists
Delay of 20 mins
Participants had to recall words in correct order
It was found that recall was more accurate for dissimilar meaning words (85% correct) compared to similar meaning words. (55%)
There was no difference in accuracy for acoustically similar.
The results imply that LTM involves the use of semantic encoding
Similar meaning thugs are likely to get muddled up.
Who was the multi store model developed by
Atkinson and Shriffin 1968
Bahrick et al 1975
Very long term memory
Nearly 400 American ex high school students aged between 17 and 74
Various tests including a free recall test where participants tried to remember names of people is a graduate class, a photo recognition test consisting of 50 photos and a name recognition test.
Results showed that participants tested within 15 years of graduation were about 90% accurate in identify names and faces
Recognition memory was better than recall because they were given a cue.
Concluded that classmates are rarely forgotten. Recognition is better than recall
Primacy and recency effects
It has been found that if people are given a relatively long list of words and asked to call them, then best recall is for the early items (primacy) and the later items (recency)
It has been argued that the recency effect is because some words are still in STM and so can be easily recalled.
The primacy effect if thought to be become early words in the list have been rehearsed and placed into LTM.
The middle words cannot be rehearsed and out into LTM as they are displaced by incoming words.
This supports that STM and LTM are separate.
Evidence that STM and LTM are sperate
Encoded in different ways (baddeley)
Evidence of primacy and recency effects in the serial position effect
Evidence from studies of patients with memory problems following brain damage.
HM
In 1953, HM underwent surgery for very severe epilepsy
The surgery aimed to remove areas of the brain thought to be at the heart of his epilepsy. In particular, an area known as the hippocampus was removed.
The surgery did reduce his epilepsy, however it was discovered that it drastically altered his memory. He was no longer able to form new long term memories. He can recognise people and events from his childhood.
KF
Shallice and Warrington reported a case study of a man who had brain damage following a motor cycle accident.
KF had a greatly reduced digit span and reduced recency effect suggesting impaired short term memory. However, he could form long term memory.
This evidence adds further support to the idea that short term and long term memories are separate.
His STM was reduced to 3-4 words at a time however his memory for images was still 7+-2. This provides evidence against the multi store model because it suggests there are 2 types of short term memory.
The working memory model
The working memory model is an explanation of how one aspect of memory (STM) is organised and how it functions
Central executive
Coordinates the activities of the 3 sub systems in memory
Phonological loop
Deals with auditory info
Inner voice- rehearses info
Inner ear- stores sounds
Visio spatial ketch pad
Deals with visual info
Visual cache- stores images
Inner scribe - stores spatial info
Episodic buffer
The component which brings together material from the other subsystems into a single memory
Provides a bridge between STM and LTM
How does KF support working memory model?
After brain damage, KF had poor STM ability for verbal information but could process visual information normally.
This suggests that just his phonological loop had been damaged, leaving other areas of memory intact.
This supports the existence of a separate visual and acoustic store.
However, evidence from brain damaged patients may not be reliable because it concerns unique cases with patents who have had traumatic experiences.
Baddeley
Evidence for the phonological loop
Participants were given lists of 5 short words and lists of long words. Their memory for the different lists was tested immediately.
They had to recall the words in order. The number of words recalled for the ‘short’ word lists and long words were compared.
It was found that more words were called if the words were shorter.
Baddeley argued that this word length effect is seen because when trying to remember words,new rehearse them using our inner voice. The ability of our inner voice to rehearse words is limited by the length of time it takes to ‘say’ the word.
So if it takes longer to say the words, then the words will have started to decay before we have finished rehearsing the list and we will start to make errors.
Weaknesses of the working memory model
Only gives us a detailed understanding of short term memory.
Our current understanding of the central executive is relatively poor and the roles of the central executive are rather vague
Interference theory of forgetting
This theory suggests that we forget due to new or old information affecting our memory.
Proactive interference is when old information interferes with new information.
Retroactive interference is when new information interferences with old information
Baddeley and Hitch
Interference theory of forgetting
Participants who had played a varying number of rugby games had to remember as many teams they had played against as possible.
It was found that forgetting was more due to the number of games played than the time passed between games.
The participants who played lots of games recently have less new info to interfere
Problem of the interference theory
It only explains forgetting when there are 2 similar bits of info
Retrieval cue failure
This occurs when the information is still in long term memory but there aren’t enough cues to retrieve the information.
Our memories can only be retrieved if we have cues or promos to help retrieve them
Godden and Baddeley
Retrieval cue failure
16 divers were split into 4 groups
Learned words on land, tested on land
Learning words on land, tested underwater
Learned words under water, tested underwater.
Groups A and C learned and test on words in the same place and these groups had the best recall. This is because the external cues available at learning were the same as at recall
Cue
A trigger of info that allows us to access memory
Problems with godden and baddeleys divers study
Small sample
Hard to find environments as different as on land and under water, in real life contexts won’t be as different.
Eye witness testimony
The ability of people to remember the details of events such as accidents which they’ve observed.
Factors which affect the accuracy of eye witness testimony
Leading questions
Anxiety
Post event discussion
The cognitive interview
crop not crap
Recreate the context- witnesses should rerun to the original crime scene and imagine what the environment was like and their emotions
Report every detail- witnesses are encouraged to include every single detail of the event even though it may seem irrrelevant. Trivial details may be important and could trigger other memories
Recall the event in different orders- events should be called in a different order to the original sequence. Eg start with what happened last
Report from different perspectives- witnesses should recall the incident from other people’s perspective
Gabbert
Post event discussion
Participants watched a video of a girl stealing a wallet. However, half of the participants saw the video with the actual footage of the girl stealing the wallet. The other half saw the video from a different perspective and didn’t actually see the physical act of the girl stealing the wallet.
Participants from each group were then paired up to discuss the case and were asked what they had seen and whether they thought the girl was guilty
71% of participants claimed to have seen the inns which they definitely did not.
By discussing an event with other people who had seen the event from a different perspective, memories can be altered
Loftus and Palmer
Leading questions
Participants were shown a video of 2 cars colliding. They were asked to estimate how fast the cars were going at the time but the wording of the question was altered.
Some participants were asked how fast were the cars going when they smashed into each other and others were asked how fast were the cars going when they hit each other.
Participants gave faster estimations of speed if they heard the word smashed. (Mean estimate 41mph) than the word hit (34mph)
Also those who heard to word smashed were more likely to say they had seen broken glass
Concluded that what we are asked after an incident can become mixed with our memory
Loftus
Anxiety
Participants were left in a waiting area outside a lab
In the 1st situation, they overheard a discussion followed by a man holing a pen and with grease on his hands.
2nd situation p- overheard a heated discussion followed by a man with blood stained knife
Participants were then asked to identify the man from a set of 50 photos
49% correctly identified man holding pen
33% correctly identified the mean with knife
Participants were less able to correctly recall the man with the knife because they had their attention absorbed by the knife. This has become known as weapon focus.
