Memory Flashcards
What is the sensory memory/register
Initial contact for stimuli
Stores information from senses
SM is only capable of retaining information for a very short time and if we don’t pay attention to it it fades quickly (spontaneous decay)
What are the types of memory
Sensory memory/register
Short term memory
Long term memory
What is memory
The process by which we retain information about events that have happened in the past
What is short term memory
The information we are currently aware of or thinking about
The information found in short term memory comes from paying attention to sensory memories
What is long term memory
Continual storage of information which is largely outside of our awareness, but can be called into working memory to be used when needed
What is duration of memory
How long (in time) a memory lasts before it is no longer accessible
STM and LTM differ in duration
What is the duration of short term memory
Short term memories last for a very short period of time, unless they are rehearsed or paid attention to.
Therefore STM is limited in duration.
What is the duration of long term memory
Long term memories can last anywhere from 2 minutes to 100 years.
LTM has an unlimited duration
How are the different types of memory coded
Sensory register:
Coded through visual, auditory or tactile
Short term memory:
Coded through acoustic (sound)
Long term memory:
Coding is usually semantic (the meaning of the information)
Different types of long term memory
Episodic memory
Semantic memory
Procedural memory
What is episodic memory
Stores information about events you have experiences
Can contain information about time and place, emotions you felt, and the details of what happened
Memories are declarative - means they can be consciously recalled
What is semantic memory
Stores facts and knowledge that have been learnt and can consciously recall
It doesn’t contain details of the time or place where you learnt the information - it’s simply the knowledge
What is procedural memory
Stores the knowledge of how to do things
E.g. walking, swimming or playing piano
This information can’t be consciously recalled
What is rehearsal
Rehearsal: a way of transferring information into LTM
E.g. by repeating it over and over again or by attending to it
Method for Peterson and Peterson study of the duration of STM
Participants were shown nonsense trigrams (3 random consonants, e.g. CVM) and asked to recall them after either 3, 6, 9, 12, 15 or 18 seconds.
During the pause, they were asked to count backwards in threes from a given number.
This was an ‘interference task’ to prevent them from repeating the letters internally
Results for Peterson and Peterson study of the duration of STM
After 3 seconds, participants could recall about 80% of trigrams correctly.
After 18 seconds, only 10% were recalled correctly
Conclusion for Peterson and Peterson study of the duration of STM
When rehearsal is prevented, very little can stay in STM for longer than about 18 seconds
Evaluation for Peterson and Peterson study of the duration of STM
The results are likely to be reliable- it was a laboratory experiment where the variables can be tightly controlled.
However, nonsense trigrams are artificial, so the study lacks ecological validity
Only one stimulus was used- the duration of STM may depend on the type of stimulus.
Each participant saw many different trigrams. This could have led to confusion, meaning the first trigram was the only realistic trial
Method for Bahrick et al’s study for long term memory
N= 392 were asked to list names of their ex-classmates (called a ‘free-recall’ test)
They were then shown photos and asked to recall the names of the people shown (photo-recognition test) or given names and asked to match them to a photo of the classmate (name-recognition test)
Results for Bahrick et al’s study for long term memory
Within 15 years of leaving school, participants could recognise about 90% of names and faces.
They were about 60% accurate on free recall.
After 30 years, free recall had decline to 30% accuracy.
After 48 years, name-recognition was about 80% accurate and photo-recognition was about 40% accurate
Conclusion for Bahrick et al’s study for long term memory
This study is evidence of VLTMs in a real-life setting.
Recognition is better than recall, so there may be a huge store of information but it is not always easy to access all of it- you just need help to get to it
Evaluation for Bahrick et al’s study for long term memory
This was a field experiment and had high ecological validity.
However, in a real-life study like this, it is hard to control all the variables, making these findings less reliable- there is no way of knowing exactly why information was recalled well.
It shows better recall than other studies on LTM but this may be because meaningful information is stored better.
This type of information could be rehearsed, increasing the rate of recall.
This means the results cannot be generalised to other types of information held in LTM.
Method for Baddeley’s study for investigating coding in STM and LTM
Participants were given four sets of words that were either acoustically similar, acoustically dissimilar, semantically similar or semantically dissimilar.
The experiment used an independent groups design- participants were asked to recall the words either immediately or following a 20- minute task
Results for Baddeley’s study for investigating coding in STM and LTM
Participants had problems recalling acoustically similar words when recalling the word list immediately (from STM).
If recalling after an interval (from LTM) they had problems with semantically similar words
Conclusion for Baddeley’s study for investigating coding in STM and LTM
The patterns of confusion between similar words suggest that LTM is more likely to rely on semantic coding and STM on acoustic coding
Evaluation for Baddeley’s study for investigating coding in STM and LTM
This is another study that lacks ecological validity.
There are other types of LTM and other methods of coding which this experiment did not consider.
The experiment used an independent groups design so there was not any control over participant variables.
Method of Jacobs study on the capacity of STM
Participants were presented with a string of letters or digits
They had to repeat them back in the same order
The number of digits or letters increased until the participant failed to recall the sequence correctly
Results of Jacobs study on the capacity of STM
The majority of the time, participants recalled about 9 digits and about 7 letters (aged 8 years)
This capacity increased with age during childhood
Conclusions of Jacobs study on the capacity of STM
Based on the range of results, Jacobs concluded that STM has a limited storage capacity of 5-9 items.
Individual differences were found, such as STM increasing with age, possibly due to use of memory techniques such as chunking.
Digits may have been easier to recall as there were only 10 different digits to remember, compared to 26 letters
Evaluations of Jacobs study on the capacity of STM
Jacobs’ research is artificial and lacks ecological validity- it is not something you would do in real life.
Meaningful information may be recalled better, perhaps showing STM to have an even greater capacity.
Also, the previous sequence recalled by the participants might have confused them on future trials
How do we use chunking to remember information
Miller found that people could remember about 7 items
He said that the capacity of STM is 7 plus or minus 2
We can use chunking to combine individual letters or numbers into larger, meaningful units
STM can hold around 7 pieces of chunked information, increasing STM’s capacity
How can information be encoded
Visually
Acoustically (sounds)
Semantic (meaning)
How is STM and LTM encoded
STM is encoded acoustically
LTM is encoded semantically
What are the two subdivisions of LTM
Explicit and implicit
Explicit subdivision of LTM
Explicit (declarative) as you can put it into words
These have to be consciously thought about to be recalled
Often formed through several combined memories
These include semantic and episodic memories
Implicit subdivision of LTM
Implicit (non-declarative) which is more difficult to put into words
These can be recalled without conscious thought
These include procedural memories
(Actions that happen unconsciously)
What is episodic memory
Personal experiences, these are time stamped
Conscious effort to recall
Strength of memory is influenced by emotion
Where is episodic memory stored
Right prefrontal cortex:
The prefrontal cortex in the forward part of the frontal lobe is associated with initial coding of episodic memory
Hippocampus:
Memories of the different parts of an event are located in the different visual, auditory, olfactory areas of the brain, but are connected together in the hippocampus to create a memory of an episode
What is semantic memory
Concerns factual knowledge an individual has learned
These are not time stamped
Linked to episodic as new knowledge is linked to experience
Where is semantic memory stored
Hippocampus
Left prefrontal cortex
Coding associated with the frontal and temporal lobes
What is prodedural memory
Concerned with learning motor skills
Without conscious effort
Difficult to explain in words
Also involved in language
Where is procedural memory found
Motor cortex and prefrontal cortex
These areas are associated with procedural LTM and aid in the memories of how to walk
Cerebellum
The cerebellum helps with timing and coordination of movements, making them smooth and precise
Recent research also suggests a role in higher cognitive processes
Method of Sperling study of the sensory register
In a laboratory experiment, participants were shown a grid with three rows of four letters for 50 milliseconds.
They then had to immediately recall either the whole grid, or a randomly chosen row indicated by a tone (high, medium or low) played straight after the grid was shown.
Results of Sperling study of the sensory register
When participants had to recall the whole grid, they only managed to recall four or five letters on average.
When a particular row was indicated, participants could recall an average of three items, no matter which row had been selected
Conclusion of Sperling study of the capacity of STM
The participants did not know which row was going to be selected, so it could be concluded that they would have been able to recall three items from any row, therefore almost the whole grid was held in their sensory register
They could not report the whole grid because the trace faded before they could finish recall
Evaluations of Sperling study of the capacity of STM
Because this was a laboratory experiment, it was highly scientific.
The variables could be controlled, and it would be easy for someone to replicate the study.
However, the artificial setting of the study means that it lacks ecological validity- people do not normally have to recall letters in response to a sound, so the result might not represent what would happen in the real world
What does the multi-store model suggest
The memory consists of three stores:
A sensory register
A short term store
Long term store
Information has to move through these stores to become a memory
What type of information goes into the sensory register in the multi-store
Information from the environment (e.g. visual or auditory)
This isn’t noticed much but if it is paid attention to, or thought about then it will pass into short term memory
How information from STM moves into LTM in the multi store model
STM has a finite capacity and duration
But if information is processed further (rehearsed) then it can be transferred to LTM
This information in the LTM is permanent
Model of the multi-store theory
Sensory input-> sensory register—(attention)–>STM—(rehearsal)–>LTM
Info can leave sensory register through spontaneous decay
STM can be backed up by rehearsal
Info can leave STM and LTM through forgetting
How does the primacy effect show that memory is made up of separate stores
Research shows that ppts are able to recall the first few items of a list better than those from the middle
The multi-store model explains this because earlier items will have been rehearsed better and transferred to LTM
If rehearsal is prevented by an inference task, the effect disappears
How does the recency effect show that memory is made up of separate stores
Ppts tend to remember the last few items better than those from the middle of the list
As STM has a capacity of around 7 items, the words in the middle of the list, if not rehearsed, are displaced from STM by the last few words heard
These last words are still in STM at the end of the experiment and can be recalled
How do people with Korsakoff’s syndrome show that memory is made up of separate stores
This is amnesia mostly caused by chronic alcoholism
People can recall the last items in a list (unimpaired recency effect), suggesting an unaffected STM
However, their LTM is very poor
This shows the model that STM and LTM are separate stores
How does Milner’s case study show that memory is made up of separate stores
Case study on patient called HM who had suffered from severe and frequent epilepsy
Seizures were based in the hippocampus
This area was surgically removed
Operation reduced epilepsy but led to memory loss
Could still form short term memories, but was unable to form new long term memories
Shows that different types of memory are separate items in the brain
Negative evaluation for the Multi-Store model: There is more than one type of LTM
What’s wrong with the model ( Ltm)
There is a lot of research to suggest that similarly to STM, it is not a unitary store.
We have different LTM stores for facts and memories of events.
Negative evaluation for the Multi-Store model: There is more than one type of rehearsal
Type of rehearsal is more important than amount
- Maintenance: only maintained in the STM
- Elaborative rehearsal: linking existing knowledge or meaning
Limitations of the multistore memory
States information is transferred from STM to LTM through rehearsal
In real life people don’t do lots of rehearsal yet they still transfer information into LTM
Rehearsal is not always needed and some items can’t be rehearsed (e.g. smells)
Assumes there is only one short term memory store and long term memory store
How was the working memory model devised from experimental evidence
Ppts found it difficult to perform two tasks simultaneously that use the same system
E.g. saying “ the the the” while silently reading something is difficult
Both these tasks use the phonological loop which has limited capacity so can’t cope with both tasks and performance in one or both will be affected
If two tasks tasks involve different systems, performance isn’t affected on either tasks
E.g. saying “the the the” while tracking a moving object
Different components of working memory model (from top to bottom in diagram order)
. Central executive
↕️ ↕️. ↕️
Phonological loop Episodic buffer visuo-spatial sketch pad
Phonological store
Articulatory process
↕️ ↕️. ↕️
. Long term memory
What is the central executive in WMM
Central executive:
Direct attention to tasks
The central executive decides what working memory pays attention to
E.g. two activities come into conflict such as driving and talking
Rather than hitting a cyclist who is wobbling, it is preferable to stop talking and concentrate on driving
Central executive directs attention and gives priority to particular activities
What is the phonological loop in WMM
Phonological loop: 1st slave system
Limited capacity
Deals with auditory information and preserves word order
Baddeley further divided it into:
• Phonological store: holds words heard
• Articulatory process: holds words heard/ seen and silently repeated like an inner voice
This is a kind of maintenance rehearsal
What is the visuo-spatial sketch pad in WMM
Visuo-spatial sketch pad: 2nd slave system
Visual and/or spatial information stored here - inner eye
• Visual = what things look like
• Spatial = relationships between things
Limited capacity
Logie suggested subdivision:
• Visuo - cache (store)
• Inner scribe for spatial relations
What is the episodic buffer in WMM
Episodic buffer: 3rd slave system
Limited capacity
General store
(added in 2000)
What do experiments on memory assume
They assume that if you can’t retrieve a memory then it is forgotten
What is forgetting from STM explained by
Forgetting information from STM is thought to be down to an availability problem
This is where the information is no longer available because of the limited capacity or limited duration of STM
The information may have been pushed out (displaced) or simply have faded away (decayed)
How is forgetting from LTM explained by
Forgetting from LTM can be caused by decay (availability problem)
Can also be because:
The information was stored, but is hard to retrieve (accessibility problem)
e.g. reading something a long time ago, to remember it you need a lot of help to recall it
The information is confused (interference problem)
e.g. two pieces of learnt information are too similar, and you can’t tell them apart easily
What is retroactive interference
This is where new information interferes with the ability to recall older information
Underwood and Postman’s experiment on retroactive interference
Both groups given list of paired words to learn (e.g. cat-tree)
Experimental group given second list of words to learn, where only first words the same (e.g. cat-dirt)
Control group not given second list
Both groups tested on recall of first list and control group performed better
This suggest retroactive interference had affected experimental group
What is proactive interference
This is where older information interferes with the ability to recall new information
Underwoods experiment on proactive interference
If people had previously learnt 15 or more words lists during the same day, a day later their recall of the last word list was around 20%
If they hadn’t learnt any earlier lists, recall a day later was around 80%
Concluded that proactive interference from earlier lists had affected the participants’ ability to remember later ones
Strengths of interference theory
Supported by many of studies which were mostly controlled lab experiment
Also has lots of evidence for interference in real life settings
Weaknesses of interference theory
Interference effects seem much greater in artificial lab setting than in real life, theory may not be as strong as once thought
Gives explanation for why we forget, but doesn’t go into cognitive or biological processes involved so does not given full explanation
What is the retrieval failure theory
Suggests that being able to recall a piece of information depends on getting the right cue
We have more of a chance of retrieving the memory if the cue is appropriate
What can act as cues in the retrieval failure theory
Cues can be internal (e.g. mood) or external (e.g. context, like surroundings or situations)
How do we remember more in retrieval failure theory
We remember more if we are in the same mood/context as we were in when we coded the information originally
Known as cue-dependent learning
Method of Tulving and Psotka’s study of forgetting in LTM
Compared the theories of interference and cue-dependant forgetting
Each ppt was given either 1,2,3,4,5 or 6 lists of 24 words
Each list was divided into 6 categories of 4 words
Words were presented in category order
After the lists were presented, in one condition, ppts were given all the category names and had to try to recall words from the list - free cued recall
Results of Tulving and Psotka’s study of forgetting in LTM
In the total free recall condition, there seemed to be evidence of retroactive interference
Ppts with 1 or 2 lists to remember had higher recall than those with more lists to remember
This suggests that later lists were interfering with remember the earlier lists
Conclusion of Tulving and Psotka’s study of forgetting in LTM
The results suggests that interference had not caused forgetting
Because the memories became accessible is a cue was used, it showed that they were available, but just inaccessible
Therefore, the forgetting shown in the total free recall condition was cue-dependent forgetting
Evaluation of Tulving and Psotka’s study of forgetting in LTM
Laboratory study so highly controlled
Reduces effects of extraneous variables
Study lacks ecological validity as the study only tested memory of words, so the results can’t reliably be gene to information of other types
What is eyewitness testimony
EWT
Evidence provided by people who witnessed a particular event or crime
Relies on recall from memory
Witnesses are often inaccurate in their recollection of events and the people involved
Examples of eye witness testimony
Descriptions of criminals (e.g. hair colour, height)
Crime scenes (e.g. time, date, location)
Methods of Loftus and Palmer’s study into eyewitness testimony
Experiment 1:
Ppts shown a film of a multiple car crash
Asked a series of questions including “how fast were the cars going”
In different conditions, the word “hit” was replaced with “smashed”, “collided”, “bumped” or “contacted”
Experiment 2:
Ppts were split into 3 groups
1 group given the verb “smashed”, another “hit” and the third was a control group who didn’t get any indication of the vehicle’s speed
A week later, the ppts were asked “did you see any broken glass
Results of Loftus and Palmer’s study into eyewitness testimony
Experiment 1:
Ppts given the word “smashed” estimated the highest speed and those given the word “contacted” gave the lowest estimate
Experiment 2:
Although there was no broken glass in the film, ppts were more likely to say that they’d seem broken glass in the “smashed” condition
Conclusion of Loftus and Palmer’s study into eyewitness testimony
Leading questions can affect the accuracy of people’s memories of an event
Evaluation of Loftus and Palmer’s study into eyewitness testimony
Implications for questions in police interviews
Artificial experiment
Watching video is not as emotionally impactful as a real life event which could affect recall
Later study where the ppts thought they’d witnessed a real robbery could give an accurate description of robber
Experimental design lead to demand characteristics
Leading questions might have given ppts clues about the nature of the experiment, so they may have acted accordingly
This reduced validity and reliability of the experiment
Negative evaluation for Loftus and Palmer’s study: Ecological validity
This was low because it was a laboratory study, and the participants knew they were taking part in an experiment.
In real-life situations there would be an element of surprise, so you might not be paying attention.
There would be an increase in emotion – such as fear, shock, etc. There may be victims.
You might not be asked questions until some time later.
You may have the opportunity to discuss what you saw with other people
Method of Loftus and Zanni’s study into leading questions
Ppts were shown a film of a car crash
Asked either “did you see the broken headlight” or “did you see a broken headlight”
There was no broken headlight shown in the film
Results of Loftus and Zanni’s study into leading questions
17% of those asked about “the” broken headlight claimed they saw one
This was compared to 7% in the group asked about “a” broken headlight
Conclusion of Loftus and Zanni’s study into leading questions
The simple use of the word “the” is enough to affect the accuracy of people’s memories of an event
Evaluation of Loftus and Zanni’s study into leading questions
Like the study by Loftus and Palmer this study has implications for eyewitness testimony
Laboratory study so there is control over extraneous variables
Possible to establish cause and effect
Study was artificial (ppts shown film of car crash, not actual car crash)
So study lacked ecological validity
What did Shaw’s study on post event discussion show for accuracy of recall
When a ppt and confederate were shown a video of a staged robbery and were interviewed
When ppt was asked first, response was accurate 58% of the time
This increased to 67% when the confederate answered accurately first
This decreased to 42% when confederate gave inaccurate answers first
What did Gabbert’s study when info is received through a conversation show for accuracy of recall
Two groups of ppts (young adults and older adults)
Both groups watched stage crime and were exposed to misleading info either by conversation with confederate or reading report of the crime from confederate
Then given recall test
Showed that both groups were more likely to report inaccurate info after conversation with confederate and not from reading report
How can schemas have an effect on eye witness testimony
These are simplified representations of things based on our experience
Memory capacity limitations prevent us from remembering precise details about our everyday lives, but schemas allow us to overcome these limitations because we can summarise the regularities in our lives
However, we may mistakenly ‘recall’ events that never really happened because they make sense within a particular schema
How can anxiety affect focus and EWT
Small increases in anxiety and arousal may increase the accuracy of memory
But high levels have an effect on accuracy
Accuracy is highest when anxiety is at the correct medium level (not too high or low)
How can the amount of anxiety expressed in crimes affect EWT
In violent crimes where anxiety and arousal are likely to be high
Witness may focus on central detail (e.g. a weapon)
May neglect other peripheral details (e.g. clothes of criminal)
Method of Loftus’ study on weapon focus in EWT
Independent groups design where ppts heard a discussion in a nearby room
In one condition, a man came out of the room with a pen and grease on his hands
In the other condition, the man came out carrying a knife covered in blood
Ppts had to identify the man from 50 photos
Results of Loftus’ study on weapon focus in EWT
Ppts in the first condition were 49% accurate
Accuracy in condition 2 were 33% correct
Why was the cognitive interview technique developed
Developed to try to increase the accuracy of witness’ recall of events during police questioning
What happens in cognitive interviews
Interviewer tries to make witness relaxed and tailors their language to suit the witness
Witness mentally recreates environmental context (sights and sounds) and internal context (mood) of the crime scene
Witness reports absolutely everything that they can remember about the crime, even irrelevant details
Witness asked to report details of the crime in different orders
Witness asked to recall events from various different perspectives
Interviewer avoids any judgmental and personal comments
Enhanced cognitive interview method
Improves the quality of the communication between interviewer and witness
The interviewer not distracting the witness with unnecessary interruptions/questions
The witness controlling the flow of information
Asking open ended questions
Getting the witness to speak slowly
Ppts being reminded not to guess and to use the ‘don’t know’ option when necessary
Reducing anxiety in witnesses
Conclusion of Loftus’ study on weapon focus in EWT
When anxious and aroused, witnesses focus on a weapon at the expense of other details
Evaluation of Loftus’ study on weapon focus in EWT
High ecological validity
Ethical issues as ppts may have been distressed
