Memory Flashcards
What is duration ?
The length of time information can be stored in memory
What is capacity ?
The amount of information that can be stored in memory
What is coding ?
Memory encoding is a process by which the sensory information is modified and stored in the brain.
The most common forms are visual, acoustic and semantic.
What are the different types of memory stores ?
Sensory memory (SM)
Initial contact for stimuli.
Short term memory (STM)
The information we are currently aware of or thinking about.
Long term memory (LTM)
Continual storage of information which is largely outside of our awarenes
What are the capacity’s of the different types of memory stores ?
SM: has a very large
capacity
STM: has a limited capacity
of 7+/-2 items
LTM: has a potentially
unlimited capacity
Who came up with the digital span technique ?
Jacobs 1887
Jacob’s research on capacity :
He was one the first to use the digit span technique to assess the capacity of STM.
He found the average span for numbers to be 9.3 items
For letters the average decreased to 7.3 items
Miller’s magic number :
George Miller (1956) reviewed psychological research +concluded that ’the magic number is 7 plus or minus two.’
He found people could recall around 7+/-2 items.
Miller’s chunking :
Miller argued that our capacity for remembering information can be increased if we chunk items together.
If we find links between information and group them together then capacity can be increased.
Research into capacity - overestimation of the STM capacity :
Limitation
Cowan (2001) conducted a review of research and concluded that the capacity of STM is closer to 4 chunks of information.
This estimate falls towards the lower end of Miller’s suggested capacity of 5, suggesting that 4 may be a more appropriate “Magic Number” than 7.
However, it is important to consider that memory can be influenced by individual differences, which may make it challenging to draw universal conclusions in this area of research.
Research into capacity - absence of specification regarding the size of a chunk.
Limitation
Simon (1974) discovered that individuals have a smaller STM capacity when dealing with larger chunks, such as 8-word phrases, compared to single syllable words.
This suggests that Miller’s explanation alone is not sufficient to fully account for the capacity of STM.
However, despite this limitation, the research does support the perspective that STM does possess a limited capacity.
Research into capacity - capacity isn’t uniform for everyone
Limitation.
The presence of individual differences impact the results.
Jacobs’ study demonstrated that digit span recall consistently increased with age. On average, 8-year-olds remembered 6.6 digits, while 19-year olds remembered 8.6 digits.
This suggests that brain capacity may increase with age or that individuals develop improved strategies to enhance their digit span.
Therefore, caution should be exercised when generalising research findings on capacity, as age is an individual difference which influences the capacity of STM.
Research into capacity - lack of ecological validity
Limitation
Due to the artificial settings in which the research is conducted.
Studies by Jacobs and Miller, utilised meaningless words, numbers, and objects to test participants’ recall, which does not accurately reflect how memory is typically used in real-world contexts.
In everyday life, memory often carries much more personal significance, such as remembering people’s birthdays or recalling daily activities.
Therefore, as these tasks lacked mundane realism, the results from laboratory experiments may only be cautiously generalised to real-world scenarios.
Duration of memory in different types of memory stores :
SM: Less than one second
STM: Approximately 18-30 seconds
unless information is rehearsed
LTM: Potentially lasts infinitely
Peterson and Peterson (1959) STM - aim
To investigate the duration of STM
Peterson and Peterson (1959) STM - participants
24 university students
Peterson and Peterson (1959) STM - procedure
On each of the 8 trials participants were given a consonant trigram and a three-digit number. They were asked to recall the consonant syllable after intervals of 3, 6, 9, 12, 15 or 18 seconds.
To prevent rehearsal ppts were asked to count backwards from their 3-digit number.
Peterson and Peterson (1959) STM - findings + conclusion
After 3 seconds recall accuracy was 80%
After 9 seconds recall accuracy was 20%
After 18 seconds recall accuracy was less than 10%
The duration of STM is less than 18 seconds.
Bahrick et al (1975) LTM - aim
To investigate the duration of LTM
Bahrick et al (1975) LTM - participants
392 ppts,
USA,
17-74 years old
Bahrick et al (1975) LTM - procedure
Tested photo recognition and free name recall from the participant’s high school yearbook.
Photo recognition: Had to recall the names of students from 50 photos in the high school yearbook.
Free recall: Asked to list the names they could remember from their graduating class.
Bahrick et al (1975) LTM - findings + conclusions
Photo recognition
Ppts tested within 15 years of graduation were 90% accurate
After 48 years recall declined to 70%
Free recall
After 15 years 60% accurate
After 48 years 30% accurate
Conclusion
The duration of LTM can last a very long time.
Research into duration - may not have been measuring trace decay, but displacement instead
It’s a limitation of the Peterson & Peterson study. This lowers the construct validity of the research.
participants were asked to engage in a distraction task of counting backwards in 3s or 4s.
This complex task could have overwritten the trigrams and resulted in displacement rather than solely preventing rehearsal.
Reitman (1974) conducted a study using auditory tones instead of numbers so displacement would not occur and found that the duration of STM was longer.
This suggests that the validity of the results from Peterson & Peterson was compromised due to methodological limitations.
Research into duration - Peterson & Peterson study results lack ecological validity
Limitation
The stimulus material used in the task was artificial, lacking mundane realism.
Ppts were asked to memorise trigrams, which does not reflect real-life examples of memory.
In real-life settings, people are required to remember personal events and birthdays, which hold greater personal significance than nonsensical syllables.
However, in certain everyday situations, we do need to remember meaningless information like phone numbers or postcodes.
In these instances, the trigram task may be representative of real-life memory demands.
Research into duration - high ecological validity
Bahrick’s results has higher ecological validity than Peterson & Peterson’s research on duration.
participants’ memory was tested on their own high school classmates, which increases mundane realism and enhances the generalisability of the results to other settings.
However, this approach introduces confounding variables.
some participants may have frequently looked at their yearbooks, while others did not.
This compromises the internal validity of the results, as the researchers may not accurately measure the impact of time on LTM recall.
it can be argued that Bahrick’s research demonstrates high ecological validity but low internal validity.
These considerations should be considered when generalising the findings.
Coding - different types of memory stores
SM: Modality specific (encoded in the same way it is received)
STM: Acoustically
LTM: Semantically
Research into Encoding : Baddeley (1966)
Ppts were shown a list of words and asked to recall them in the correct order.
To test STM ppts recalled the words immediately after hearing them, whereas a time interval of 20 minutes was given for LTM recall.
Research into Encoding - findings :
Participants had difficulty remembering acoustically similar words when tested
immediately (STM) but had no difficulty remembering acoustically similar words after 20 minutes (LTM).
Participants had difficulty remembering semantically similar words when tested after 20 mins (LTM) but had no difficulty remembering semantically similar words when tested immediately (STM)
Research into encoding - conclusions :
This suggests that information is coded acoustically in STM and semantically in LTM.
Research into encoding - table :
Group 1 cat, cab, can Acoustically Similar
Group 2 pit, few, cow Acoustically Dissimilar
Group 3 great, large, big Semantically Similar
Group 4 good, huge, hot Semantically Dissimilar
Research into encoding - shows existence of distinct + separate memory stored
A strength of Baddeley’s findings into coding is that they demonstrate the existence of distinct and separate memory stores.
This is evident in the finding that short-term memory (STM) is coded acoustically, while long-term memory (LTM) is coded semantically.
This discovery played a crucial role in the development of the multi-store model of memory.
Moreover, the finding which supports the multi-store model has consistently withstood the test of time, making it a reliable and enduring finding.
Research into encoding - contradictory research evidence
A limitation of Baddeley’s findings on the encoding of STM is the presence of contradictory research evidence.
Brandimote et al. (1992) discovered that participants used visual coding in STM when engaged in a visual task and prevented from verbal rehearsal before visual recall.
Additionally, Nelson and Rothbart (1972) found evidence of acoustic coding in LTM.
These findings indicate that encoding is not consistently acoustic in STM and semantic in LTM.
As a result, the generalisation of Baddeley’s findings to all types of learning is not equally applicable.
Research into encoding -lack of ecological validity
This is a limitation of Baddeley’s research.
The research was conducted in a lab setting, and caution must be exercised when generalising the findings to real-world contexts.
Baddeley utilised meaningless words to test participants’ recall, which does not accurately reflect how memory is employed in real-life situations.
In everyday life, memory often carries more personal significance (e.g. remembering people’s birthdays or recalling daily activities).
Since the task employed by Baddeley lacked mundane realism, the results may not accurately reflect how memory functions in real-world settings
What are the 2 information processing models of memory ?
- Linear models : information is shown to flow through the system in one direction.
- Passive models : the stores hold on to data before being passed on or lost.
Who created the multi store model and when ?
Atkinson and Shiffrin 1968
Research Supporting the capacity and duration of the Sensory register - Sperling
Sperling presented participants with a number of grids each containing 3 rows of 4 letters for 1/20th (50 milliseconds).
When asked to recall the whole grid, participants could only recall 4 or 5 letters HOWEVER
many claimed to have seen more.
Sperling assumed this happened because, while all letters had entered the SR they had faded before most of them could be reported. Sperling tested this claim.
This time he asked participants to recall only part of the information. He showed the 4x5 grid and then asked them to recall 1 of the rows either top, middle or bottom. This time recall was very good and suggested Iconic memory could hold 9 or 10 items.
Sperling’s research - conclusions
Capacity - The fact that Participants did not know which line they would be asked to recall, yet had much better recall than the original experiment suggests that all of the letters in the grid had been available. Demonstrating the capacity of the sensory register is larger than 4/5 letters.
Duration - The time it takes to report the letters in 1 row is much quicker than reporting the whole grid, therefore the issue of letters fading is avoided, thus recall is very good compared to recalling the full grid. This suggests that while the capacity of the SR may be large the duration is very limited at approximately 0.5 seconds.
Konkle’s 2010 research supporting the LTM
He presented participants with 2912 pictures of scenes at 3 seconds per scene followed by a test of recognition memory.
The scenes belonged to a total of 128 different general categories. LTM for these scenes was very good.
When participants chose between a previously presented scene and a new scene from a category not used during the initial presentation, they were correct 96% of the time.
Evaluation of research into the stores - practical applications
A strength of research into the nature of memory is that it has positive real world benefits.
Information about the capacity of STM is useful for teachers, students and anyone else who needs to know the cognitive limitations of people.
For example teachers can plan lessons in ways that reduce the amount of new information that needs to be held in the STM and create tasks which enabled students to transfer information into the LTM where the capacity is much larger.
simple initiatives such as the postcode system uses Miller’s research of Chunking, whereby the limited capacity of the STM can be increased if we group digits together.
research is important as it has led to techniques to improve the limits of the memory.
What is the sensory register?
The first store which holds the sensor information received through all the senses for a brief period of time. Examples include iconic (visual) and echoic (sound) memory.
What is the STM?
The memory for immediate events. These memories tend not to last for more than a minute or two, usually shorter, and disappear unless they are rehearsed. Capacity is limited to 7 plus or minus 2 individual items.
What is the LTM?
The memory for past events that can last for the life-time of a person. Its capacity is most probably unlimited.
What are key features of the MSM?
Information flows through a number of storage systems in a linear fashion (in a line)
There are three main storage systems which are unitary (each a single unit)
Information can remain in short-term memory by maintenance rehearsal, and prolonged rehearsal (sometimes called elaborative rehearsal) will create a long term memory.
The more information is rehearsed, the better it is remembered
Information can be lost from each store, but in different ways
Describing the MSM :
- The multi-store model consists of three stores: sensory register, short-term memory (STM), and long-term memory (LTM). Information flows linearly through these stores.
- Information enters the sensory register from the environment, with two main stores: echoic (auditory) and iconic (visual).
- Information in the sensory register lasts less than 3 seconds but has a high capacity.
- Information from the sensory register passes to STM only if attention is paid.
- STM has a limited capacity (7 +/- 2 items) and a duration of up to 30 seconds. Information is lost unless rehearsed. It is typically encoded acoustically.
- Maintenance rehearsal involves repeating information to keep it in STM. If rehearsed long enough, it moves to LTM, where it can last a lifetime, with unlimited capacity and semantic encoding.
- To recall information from LTM, it must be transferred back to STM through retrieval.
Evaluation of MSM- supporting evidence (primacy recency effect)
There is research that supports the separate stores identified in the Multi-store model.
Glazer and Cunitz found that if participants were allowed to immediately recall a list of one syllable words they were asked to remember, they could remember the words at the beginning and the end of the lists, but not the words in the middle. This is known as the primacy-recency effect (first and last).
This supports the MSM in that the words at the beginning of the list are rehearsed and therefore placed in LIM, but the words in the middle of the lists are quickly displaced by rehearsing the first words. The words at the end of the list are remembered because they are still fresh in STM.
These findings support the distinction of STM and LTM and the role of rehearsal in passing information from STM to LTM.
Evaluation of MSM- the STM and LTM shouldn’t be considered a unitary store
There is evidence to suggest that both the STM store and the LTM store should not be considered unitary stores.
In a case study, after a virus caused damage to the hippocampus, Clive Wearing had very little long term memory for events that had happened in his life but could stil remember skills such as playing piano, reading music and writing in a diary.
This evidence challenges the idea that LTM is a unitary store.
It demonstrates that it may store and process episodic (memory for events) and procedural (skills) long term memories differently. As a result, the tripartite approach to describing LTM was introduced.
Evaluation of MSM- fails to explain why information can transfer to LTM without rehearsal
MSM can be criticised for failing to explain why in our day to day lives a lot of information can transfer to LTM without prolonged rehearsal.
Cralk and Lockhart suggested that enduring memories are created by the processing that you do, rather than through maintenance rehearsal, things that are processed more deeply are more memorable just because of the way they are processed ‘Deep’ 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. shark) and asked a question that involved shallow or deep processing - asked whether the word was printed in capital letters (shallow) or asked wither the word fitted in a sentence (deep).
The participants remembered more words in the task involving deep processing rather than shallow processing.
This research contradicts the original claim that for memories to be transterred into LTM, maintenance rehearsal (verbal repeating) is required. Thus giving doubt to some of the assumptions of the multi-store model.
Evaluation of MSM - supportive research derived from HM’s case
HM experienced severe damage to his LTM, as evidenced by his inability to recall information such as repeatedly reading the same magazine without remembering it or recalling his earlier meals on the same day.
However, despite the LTM damage, his STM remained intact.
He performed well on tests of immediate digit span, which assesses capacity of STM.
This case study supports the MSM by providing evidence for its central feature — the existence of separate and independent memory stores for STM and LTM. This increases the validity of the model.
However, it is important to note that HM is a case study involving a single individual, and therefore, the results may not be generalisable to other individuals.
For example, HM’s epilepsy medication may have affected his brain in ways that differ from other individuals.
What are the 3 types of LTM ?
- Procedural memory
- Episodic memory
- Semantic memory
Who devised the working memory model ?
Baddeley and Hitch in 1974
WORKING MEMORY MODEL :
After the development of the MSM, research questioned the existence of a single STM store. Because we actively process information in STM, it’s far too complex to suggest that STM is just a temporary store for transferring information into LTM.
They devised the working memory model’ in an attempt to demonstrate what is happening to information when we are consciously thinking about it.
Cohen described the WMM as the explanation of conscious thoughts happening ‘now’.
What are the 4 main components of the WMM ?
- Central executive
- Phonological loop
- Visuo-spatial sketchpad
- Episodic buffer
What is the difference between an active and passive store ?
Active : visualise the relationship between objects and rehearse what you have seen.
Passive : form and colour of objects
What is the central executive ?
function is to direct attention to particular tasks, determining how the brain’s resources are allocated to tasks.
CE attends + monitors incoming information from the senses or LTM and this information is then sent to the other slave systems for processing and temporary storage.
it has very little capacity so it cannot attend to too many things at once, and it has no capacity for storing data.
It switches between different inputs.
What is the phonological loop ?
It has a limited capacity and a 2 second duration.
Its function is to store speech-based sounds for brief periods. It has two components:
• The phonological store
• The articulatory control process
What is the phonological store ?
Allows acoustically coded items to be stored for brief periods (someone talking, a melody etc.)
Hence its nickname - The Inner ear.
Primary acoustic store
What is the articulatory control process ?
Allows sub vocal repetitions of items in phonological store. This is similar to maintenance rehearsal. Hence it’s nickname - the inner voice.
What is the visuo spatial sketchpad ?
it processes + stores mental images in terms of what they look like and their place in the visual field.
It is independent from the phonological loop, and has a limited capacity.
It is used when people are planning a spatial task, e.g. reaching for their cup of coffee.
nickname is the inner eye.
Contains the visual cache (passive store) and the inner scribe (active store)
What is the episodic buffer ?
Added in 2000, the episodic buffer is a general store that allows both sound and visual information to be bound together.
It integrates information from the other systems and also offers a sense of time sequencing.
It records events (episodes) that are happening and sends information to LTM.
Like all the systems in working memory, it has a limited capacity.
Evaluation of WMM - Shallice and Warrington 1970
Research into the WMM uses case studies of brain-damaged patients.
Shallice and Warrington (1970) investigated the clinical case of KF.
It was found that KF has a selective impairment to his verbal STM, caused by a brain injury.
However, the visual functioning of his STM is not affected.
This suggests the PL and VSS subsystems are separate processes located in separate brain regions.
Evaluation of WMM - lack of clarity over the central executive
The WMM can be criticised because there is a lack of clarity over the central executive and the exact role it plays in the model.
Baddeley acknowledges this flaw in the model when he stated in 2003 “The central executive is the most important but the least understood component of working memory.”
Evidence to support this argument was conducted by slinger and Demasio (1985.
They reported on the case study of EVR who had a cerebral tumour removed. He performed well on tests of reasoning, which suggests that his central executive was intact; however, he had poor decision-making skills, which suggests that his central executive was not wholly intact.
This suggests that the original concept of the central executive needs to be more clearly specified than just being simply ‘attention’ and that perhaps it may consist of separate components.
Evaluation of WMM - Comparison to MSM
P- The WMM compares favourably to the MSM. It attempts to explain how memory functions, as opposed to simply describing the structure of memory.
E- As a result of this, it has led to a greater understanding of cognitive dysfunction e.g.
ADHD and dyslexia which are thought to be linked with impairments of working memory.
E- Research has led to a number of methods being developed to help children with
ADHD focus on tasks e.g. use brief and simple instructions so they don’t forget what they are doing (limited capacity of phonological loop).
L- The development of the working memory model has many tangible benefits that clearly demonstrate the value of the model. In comparison, the practical applications of the MSM are limited.
Evaluation of WMM - supporting evidence : separate existence of stores
P- There is evidence to support the limited capacity and separate nature of the slave systems, demonstrated by research into dual-task performance.
E- Gathercole and Baddeley (1993) found that participants had more difficulty doing two visual tasks (simultaneously tracking a moving point of light and describing the angles of the letter F) than doing both a visual and verbal task at the same time.
E-This increased difficulty is because both visual tasks compete for the same slave system, whereas when doing a verbal and visual task simultaneously, there is no competition.
L- The evidence indicates that the VSSP and the PL are separate slave systems but also demonstrates the limited capacity of the VSSP.
Main Limitation of LTM
One of the major limitations of the MSM is that its description of LTM as a single unitary store is now seen as outdated.
Many research studies have shown that there are at least three different types of long term store.
Episodic memory :
1st suggested by Tulving (1972), it is the type of LTM that gives individuals an autobiographical record of things that have happened to them (our memories of our experiences).
it is the storage of episodes that happen throughout our lives.
e.g. your last holiday
containing information about what happened, where it happened, and when it happened.
the emotional charge and the entire context surrounding an event is usually part of the memory, not just the bare facts of the event itself.
having episodic memory allows us to make predictions about what will happen to us in the future.
episodic memories are constructed, rather than reproductive, and is prone to errors and illusions.
they are subject to stereotyping, subjective interpretation, missing out information.
semantic memory :
This is a structured record of facts, meanings, concepts and knowledge about the external world that we have acquired.
It refers to general factual knowledge, shared with others and independent of personal experience and of the time and place in which it was acquired.
Semantic memories may once have had a personal context, but now stand alone as simple knowledge. It therefore includes such as capital cities, social customs, historical dates, functions of objects, vocabulary,
There is an enormous amount of information available in semantic memory, and is continually being added to.
procedural memory :
It tends to be unconscious, whereas the other two LTM are conscious.
its the unconscious memory of skills and how to do things, the use of objects or movements of the body, e.g. riding a bike.
These memories are acquired through repetition and practice, and are composed of automatic sensorimotor behaviours that are so deeply embedded that we are no longer aware of them.
Once learned, these “body memories” allow us to carry out ordinary motor actions automatically.
Evaluation of types of LTM, support biological evidence (Tulving)
There is evidence to suggest that when a person uses episodic memory, they use a different region in the brain compared with when (biological evidence) they use semantic memory.
Tulving (1989) injected himself, his wife and 4 others with particles of radioactive gold that he could use to track brain blood flow in a scanner.
He scanned each person’s brain whilst they thought about historical facts or childhood experiences.
He found in 3/6 participants (including himself), that when they were thinking about historical facts blood flow increased at the back of his brain, whereas when he thought about childhood experiences blood flow increased at the front of his brain.
The activation of the different areas of the brain when recalling facts or episodes suggests a biological basis to the different types of memory in LTM
Evaluation of types of LTM, supporting evidence (case studies) Clive wearing
In the case of Clive Wearing, as illness caused the near total destruction of his hippocampus.
This left him with an inability to store new episodic or semantic information for any more than a few seconds.
However, he was able to read, write, speak and play piano.
Other researchers investigated learning in people with Huntingdon’s Disease (a progressive, degenerative disease of the brain).
They found that HD patients had no problems learning new facts and knowledge, but had severe problems learning new motor skills.
These findings give a strong indication that damage to specific areas of the brain leave the patients with deficits in one or more types of long term memory, whilst leaving other long-term memory stores intact.
this offers support for the biological basis of separate long-term stores.
Evaluation of types of LTM, challenging research
Critics challenge the need of distinguishing between types of LTM.
Cohen and Squire suggest that semantic + episodic memory should be understood as the same type of memory, called declarative memory’.
research by Kan et al (2009) found that there was interdependence between episodic and semantic memory. Whether there are two or three types (or more) of LTM may be important when attempting to help people recover their cognitive functions after illnesses such as stokes.
(Counter point for extension:
Being able to identify different aspects of LTM has led to psychologists targeting specific kinds of memory to make people’s lives better.
Belleville et al (2006) demonstrated that episodic memories could be improved with training in older patients with mild cognitive impairment.
This shows that the tripartite division of long-term memory has had tangible benefits for people with cognitive impairment, making it a useful theory).
Evaluation of types of LTM, practical application Belleville et Al 2006
Allows psychologists to enhance specific memories and improve people’s lives.
Belleville et al. (2006) conducted a study showing that episodic memories could be enhanced in older individuals with mild cognitive impairment.
The “trained” group, which received episodic memory strategies, performed better on a test compared to the control group.
Given that episodic memory is particularly affected by mild cognitive impairment, the ability to differentiate between different types of long-term memory is valuable.
This enables targeted therapy to address specific memory deficits.
This directly impacts on enhancing the quality of life for individuals with memory problems is especially significant in the early stages of Alzheimer’s disease.
What is forgetting due to ?
The information in the LTM being confused with/or disrupted by other information during coding.
this causes inaccurate recall.
what are the 2 types of interference theories ?
- Proactive
- Retroactive
proactive interference theory :
involves memory impairment for something we have learnt by other learning that had occurred previously.
old information interferes with the new.
Jacoby et Al (2001) argued that proactive interference occurs due to the competition between the strength of old learning and the weakness of the new.
e.g. speaking Spanish fluently means it interferes when learning how to speak French
retroactive interference theory :
the disruption to recall of previously learnt material by the interference of newly learnt information.
newer information interferes with the old.
Evaluation of interference theories of forgetting - individual differences :
its failure to consider individual differences in susceptibility to interference effects.
Kane and Engle (2000) conducted a study that demonstrated how individuals with higher working memory spans were less prone to interference.
They presented participants with three-word lists to learn, and those with lower working memory spans experienced greater proactive interference when recalling the second and third lists compared to those with higher working memory spans.
This finding suggests that people are not uniformly affected by proactive interference, and the impact of interference is dependent on individual differences.
The susceptibility to interference and its influence on forgetting may vary from person to person.
Therefore, when applying the theory of interference to our understanding of forgetting, it is crucial to consider the individual context and account for individual differences in working memory capacity.
Evaluation of interference theories of forgetting - supporting evidence (Underwood)
There is research to support the impact of old information interfering with new information. Underwood (1957) showed that participants, who were repeatedly asked to learn series of word lists made far more errors as the number of lists increased, compared with when they first began the study. As the participants made more errors in the word lists shown at the end of the study, this demonstrates how the old information (the first word lists) was interfering with the newly learned information (the most recent list), which is what proactive interference would predict.
Evaluation of interference theories of forgetting - supporting evidence (Schmidt et Al)
Schmidt et al. (2000) collected a sample of 211 former students of a Dutch elementary school and sent them a map of the surrounding area of the school.
The map had the street names removed and replaced with numbers from 1 - 48.
Participants were asked to name as many as they could.
The researchers found that there was a positive association with how many times the participants had moved outside the area, and the number of names forgotten.
The researchers concluded that learning new street names (when they moved house) made recalling the old street names more difficult.
This demonstrates that retroactive interference plays a role in forgetting because the new information interferes with the old information.
It also shows that interference is key in forgetting and not just the amount of time that has passed.
This is because increased forgetting was due to how many times they had moved not how long along they moved out of the area.
Evaluation of interference theories of forgetting - fails to explain
The explanations are limited due to the focus on interference of very similar types of information. For example how one list of words interferes with another list however interference theories fail to explain how forgetting information, skills or other information happens in the majority of real life settings, where we are not juggling with similar material and yet still manage to forget a lot of what we experience. Therefore the explanations may be able to tell us how interference affects our memories in artificial situations, and of very similar types of information, but they do not explain most cases of forgetting in real-life.
retrieval failure due to absence of cues :
The reason that people forget information is because there are insufficient cues.
When information is placed in memory, their associated cues are stored at the same time.
If these cues are not avallable at the time of recall, then there is an appearance that the information has been forgotten.
This theory suggests that the information still available for recall, but it cannot be accessed until the correct cues are in place.
Tulving (1983) referred to what he called the Encoding Specifielty Principle (ESP),
This states that a cue is going to help us remember information; it has to be present during encoding (when we learn the information) and at retrieval (recall), If the cues at encoding and retrieval are different then some forgetting will occur.
For example, if you revise at college, you are more likely to retrieve the information than you are if you revise at home, as the college will act as a cue for retrieval because the surroundings were there during encoding.
Context dependent forgetting :
refers to external cues that are different when encoding information and when retrieving it.
e.g. home vs school revision
state dependent forgetting :
refers to internal cues (state of awareness) that are different during encoding and retrieving information.
e.g. encoding information while under the influence of alcohol, only to forget it the next day.
external emotional cues that were present at encoding are not present at recall.
evaluation of retrieval failure - supporting evidence of context dependent forgetting : Godden and Baddeley
There is evidence supporting the role of context to explain why we forget. Godden and Baddeley (1975) studied deep water divers and the effects of context dependent memory. Participants had to learn lists of 36 words (two or three syllables) either on land or underwater and then recall them either on land or underwater. The percentage of accurate recall is shown for the 4 conditions:
1. Learn on land - recall on land (same context)
Recall accuracy = 37%
2. Learn underwater - recall on land (different context)
Recall accuracy = 23%
3. Learn on land - recall underwater (different context)
Recall accuracy = 24%
4. Learn underwater - recall underwater (same context)
Recall accuracy = 32%
The higher percentage recall in the matched environments support the prediction that if the cues at encoding are the same as the cues at retrieval, recall is more likely, and if they are different, recall is less likely. This supports the concept of context dependent forgetting
evaluation of retrieval failure - application
In places where getting instructions correct is absolutely vital, such as soldiers in novel environments, it is important to recognise that instructions maybe more likely to be forgotten if issued back in the safety of the camp.
This would be true for many different people, such as deep water divers repairing oilrigs, astronauts, medics etc. therefore care must be taken to recognise this, and much practice in different scenarios required
The value of these explanations maybe that they are used to save the lives of people in threatening and novel situations
evaluation of retrieval failure - ability to generalise (baddeley)
Baddeley (1997) argued that these studies do not reflect real-life, and therefore the strength of the explanations should be questioned.
He claimed that the contexts or states have to be very different to have an effect and subtle changes of environment or internal states, that tend to be the norm, will not have a strong effect.
We must not make exaggerated claims about cue dependent forgetting based on evidence that alters both context and state in a dramatic way.
evaluation of retrieval failure - supporting evidence (state dependent forgetting Carter and cassaday)
There is evidence which highlights the impact of your internal state on learning and recall. when Carter and Cassaday (1998) gave anti-histamine (anti-allergy) drugs or a placebo (vitamin pills) to participants (students from Nottingham University). Antihistamines have a mild side-effect of causing drowsiness and therefore altering the state of awareness for the participants. Participants were asked to learn and recall information in four different conditions.
The results showed a marked decrease in accuracy of recall in a memory test when the participants’ internal state did not match at the time of encoding and retrieval, and an increased performance when the internal states did match.
This supports the concept of state dependent forgetting, as when the internal cues were different during encoding and retrieval, recall of a list of items was worse, as predicted by the theory.
what is EWT ?
Eye witness testimony is defined as an account or evidence provided by people who witnessed an event, such as a crime, reported from their memory.
In appeals against conviction in the US, DNA evidence has overturned over 200 cases and in 75% of these, EWT was the main evidence against them.
Many variables can influence the accuracy of EWT. These include being presented with misleading questions during police interviews, post-event discussion with other witnesses, and the anxiety that people feel if they witness or are a victim of the crime.
misleading information :
a key factor that can affect the accuracy of EWT.
it’s incorrect information given to an eyewitness following an event.
it’s mostly due to leading questions (phrased in a particular way to suggest a certain answer) or post event discussion (co witnesses discuss what they have seen).
Loftus and Palmer 1974 :
Two experiments are reported in which subjects viewed films of automobile accidents and then answered questions about events occurring in the films.
In experiment 1, 45 university students were divided into 5 conditions.
The question “About how fast were the cars going when they smashed into each other?” elicited higher estimates of speed than questions which used the verbs collided, bumped, contacted, or hit in place of smashed.
e.g. smashed 40.5 mph, contacted 31.8 mph.
In a second similar experiment, 150 different students were split into three conditions, one condition were asked the question with ‘smashed, the other condition were asked the question with hit and the other condition had no question (control).
On a retest one week later, those subjects who received the verb smashed were more likely to say yes to the question ‘did you see any broken glass’ even though there wasn’t any.
In both of these experiments, it can be seen the memory of the incident was changed due to the leading question in the first experiment.
These results get are consistent with the view that the questions asked subsequent to an event can cause a reconstruction in one’s memory of that event.
2 explanations for Loftus and Palmer experiment :
- Response bias
The researchers question changed the way pts responded to the question but did not affect their actual memory - Substitution explanation (most likely)
The intensity of the verb changed the pts actual memory. This explanation is most likely due to the 2nd ‘broken glass’ experiment.
In a follow up experiment pts were more likely to report seeing broken glass when questioned using the verb ‘smashed’ compared to ‘hit’. There was no broken glass, so it shows that memories had actually been altered.
Evaluation of misleading information - validity
participants watched film clips of car accidents rather than witnessing real accidents.
the artificial setting may not accurately capture the emotional stressful nature of witnessing an actual car crash, which research suggests can influence memory.
the findings may have limited generalisability to real life cases of accidents or crimes, as the ecological validity of the study is compromised.
the findings don’t represent the complexity of real world situations.
this can have implications for the legal system, as overly pessimistic views about the accuracy of EWT may cause unjust outcomes.
Evaluation of misleading information - application
it has been used to train professionals (e.g. the police),not using leading questions when questioning witnesses.
Loftus’ work underscores this importance through the case of Ronald Cotton, who was wrongly convicted of rape based on inaccurate EWT provided by the victim.
he spent 10 years in prison before being released.
Loftus stressed the need for caution among police officers as improper questioning techniques can distort recall (memory).
Psychologists have used research to develop the CI, which increases accuracy of EWT.
this has led to positive implications and shows the value of the research conducted into misleading information.
Evaluation of misleading information - reliability
many laboratory studies have found similar findings when participants are faced with leading questions.
However one experiment found that leading questions did not change the accuracy of the
EWT when the misleading information was obviously incorrect.
Loftus (1979) showed participants slides that showed the theft of a large purse from a handbag. 98% of the participants remembered the correct colour of the purse. They were then asked to read an account of the incident that was allegedly written by a professor of psychology. In this account, the professor stated that the purse was brown, a false statement as the original colour was red. Only 2 participants changed their answer to brown on a subsequent test, with most keeping to their original identification of a red purse.
This means we cannot reliably conclude that all misleading information will have the same effect in all circumstances. The testimony is unlikely to change if the information they receive and the event they witnessed was obviously different.
Evaluation of misleading information - lack of consideration for individual differences
evidence suggests that older people are less accurate than younger people when giving EWT.
Anastasi and Rhodes (2006) found that 18-25 and 35-45 years olds were more accurate than 55-78 year olds in a facial recognition task. However, all age groups were accurate when identifying people of their age group (known as own age bias).
This suggests that findings on EWT may have low population validity as the findings may not be applied to all age groups, as there may be a difference in accuracy between age groups and also be a bias.
The results from studies should therefore be generalised with caution and the age of the ppts should be considered when applying the findings.
Post event discussion :
This is when misleading information can also come from other sources, for example other co-witnesses, when they discuss the details of a crime or accident, following an incident.
Co-witnesses are likely to discuss the event with eye-witnesses and this could be a source of further distortion. 58% of eye-witnesses had reported discussing the incident post event with other witnesses (Skagerburg and Wright, 2008)
Errors in eyewitness accounts can occur when a witness comes into contact with post-event ‘misinformation’.
e.g. through face-to-face interaction, in particular via conversation with other individuals who also witnessed the crime.
The current research compares this kind of misinformation with the non-social post event narrative method typically employed in lab studies.
Gabbert el Al (2003 post event discussion)
investigated the effect of post-event discussion on the accuracy of eyewitness testimony.
sample consisted of 60 students from the University of Aberdeen and 60 older adults recruited from a local community.
Participants watched a video of a girl stealing money from a wallet.
The participants were either tested individually (control group) or in pairs (co-witness group).
Those in the co-witness group were told that they had watched the same video, however they had in fact seen different perspectives of the same crime and only one person had actually witnessed the girl stealing.
Participants in the co-witness group discussed the crime together.
All of the participants then completed a questionnaire, testing their memory of the event.
Gabbert el Al findings :
71% of the witnesses in the co-witness group recalled information they had not actually seen and 60% said that the girl was guilty, despite the fact they had not seen her commit a crime.
these highlight the issue of post-even discussion and the powerful effect this can have on the accuracy of eyewitness testimony.
Difference between memory conformity and memory contamination :
Conformity : witnesses go along with each other to win social approval, or because they think the other person is right.
Contamination : co witnesses discuss a crime + mix information from the other person into their own memory
Evaluation of post event discussion - validity
The mundane realism of these research findings are under scrutiny due to the controlled nature of the research.
An eye-witness to a real crime who is then involved in post-event discussion may not act in the same way as the participants under laboratory conditions.
For example, there might have been a conformity effect in this research because they knew it was a study. The outcome of the participant’s answers had no social impact and this meant no one would suffer as a result of their testimony (go to prison).
This might make them more likely to conform and recall information they hadn’t seen, as there are no consequences for doing so.
The lack of validity in laboratory research suggests we must be cautious when making firm conclusions about the role post-event discussion would play in real life testimonies.
Evaluation of post event discussion - application
police officers should advise witnesses not to discuss the case with any other co-witness and will strive to interview the witnesses as soon as possible, to prevent their testimony from being distorted by discussion with others. However, in the aftermath of an incident, it would be natural for co-witnesses to discuss what they have just seen. Thus, police officers are advised to take this into consideration when later questioning them on events. This demonstrates the value of these research findings and they can be used in many ways to improve the accuracy of testimonies.
Evaluation of post event discussion - reliability
A strength of the research into post-event discussion is the consistency of the findings. There are many research studies that have found similar findings to Gabbert et al. (2003).
For example, Gabbert et al (2007) found that participants receiving misinformation after an event were less accurate at recalling the event than controls. Especially if this information came from a social source (another person) compared to a non-social source (written account). This means the research in this area has high reliability and allows us to suggest with confidence that EWT can be distorted by post-event discussion.
Evaluation of post event discussion - false memories
strength of research on the effect of misleading information lies in the substantial support it has collected.
Loftus’s Disneyland study serves as a notable example. Participants were exposed to a fabricated print advertisement that described meeting and shaking hands with Bugs Bunny, a character from a different entertainment company. Surprisingly, participants in the “Bugs” condition reported vividly remembering shaking hands with Bugs in their childhood, despite the impossibility of this occurrence.
This study highlights how misleading information can have a profound impact on memory, leading to the creation of inaccurate or entirely false recollections.
It provides evidence that eyewitness testimony (EWT) is not always reliable and can be susceptible to distortion and manipulation.
what is anxiety ?
unpleasant emotional state where we fear that something bad is about to happen.
e.g. in stressful situations like when witnessing a crime.
it’s accomplished by physiological arousal (increased heart rate, shallow breathing).
it has an effect on performance due to the danger they perceive to be in, even though there may be some key individual differences to how people react to anxiety.
it’s a distortion of EWT and much of the research now focuses on the effects of arousal.
Yerkes Dodson effect
observation that arousal has a negative effect on performance (such as memory recall) when it’s very low or very high, but moderate levels are beneficial.
it’s used to explain errors made by eyewitnesses, particularly when recalling a violent crime.
it’s likely that the witness was in a high state of arousal during the crime so their performance in recalling details is negatively affected.
weapon focus effect
Lofts argues that anxiety is most problematic for later recall when a crime involves a weapon. Research suggests that the anxiety of seeing a weapon focuses all of vour attention of the central details (the weapon itself which means you are less able to recall the peripheral detals such as what else was going on, what the perpetrator looked like.
evidence of the weapon focus effect
Loftus et al (1987) asked participants to watch one of two sequences: a person pointing a gun at a cashier and receiving some cash, and a person passing a cheque to the cashier and receiving some cash.
Loftus found that participants correctly identified details about the incident in the ‘cheque condition more than they did the ‘gun’ condition, demonstrating the weapons focus effect
negative effect of anxiety
One argument is that anxiety creates a physiological arousal
in the body (high anxiety) which prevents us paying
attention to important cues so recall is worse.
The ‘weapon focus’ effect is when witnesses concentrate so
much on a weapon at the scene of a crime scene, that this
reduces the accuracy of recall of other details of the crime
negative effect of anxiety - Johnson + Scott 1976
Anxiety had an effect of EWT
Ppts were led to believe they were waiting to take part in a study.
Whilst seated in a waiting room ppts heard an argument in the next room.
In the low-anxiety condition a man walked through the waiting area carrying a pen with grease on his hands.
In the high-anxiety condition the argument was accompanied by the sound of breaking glass, and a man walked out of the room holding a paper knife that was covered in blood.
positive effect of anxiety
Another argument is that anxiety creates a physiological arousal in the body (high anxiety) which triggers the fight or flight response and increases alertness.
This improves the accuracy of EWT.
positive effect of anxiety - Yuille and Cutshall 1986 procedure
A real-life shooting in a gun shop in Canada where the shop owner shot a thief dead.
21 witnesses in total and 13 took part in the study.
Interviews took place 4-5 months after the original incident and were compared with the original police interviews made at the time of the shootings.
Accuracy was determined by the number of correct details reported in each interview.
The ppts were also asked to rate how stressed they felt at the time on a 7-point scale to assess their anxiety levels at the time.
evaluation of the role of anxiety in EWT - too reductionist
A limitation of studying the effects of anxiety on eyewitness testimony (EWT) is the
challenge of accurately defining and measuring anxiety.
Anxiety encompasses various components, such as cognitive, emotional,
behavioural, and physiological aspects. However, lab experiments often focus
solely on physical arousal, as suggested by the inverted-U theory, which represents
only one facet of this complex behaviour.
The reliance on the inverted-U theory to explain the impact of anxiety on EWT
recall falls short in providing a comprehensive and holistic explanation.
This limitation is significant as it hinders a complete understanding of how anxiety
may influence EWT, as it fails to account for the multi-faceted nature of anxiety
experiences.
evaluation of the role of anxiety in EWT - internal validity
Criticism of the weapon focus effect is that the effect may not be caused by anxiety, but by surprise instead.
Pickel (1998) conducted a study in a hairdressing salon, using
contrasting conditions. A confederate entered the salon carrying scissors, a handgun, a
wallet, and a raw chicken. The accuracy of the eyewitness recall served as the
dependent variable. The results showed that EWT accuracy was significantly poorer in
the high unusualness conditions, both for the chicken and the gun.
This research suggests that the weapon focus effect observed in the Johnson and Scott
study may be due to surprise rather than anxiety, as the presence of a highly unusual
item (the chicken) led to similar results as the presence of a weapon (the gun).
Therefore, the findings of Johnson and Scott’s study may not provide conclusive
evidence regarding the specific impact of anxiety on EWT.
evaluation of the role of anxiety in EWT - applications
Research into the effect of anxiety has had important real world applications. Recognising the role of anxiety in EWT has meant the police proceed with extreme caution when pursuing lines of enquiry. Today criminal investigations rarely rely on Eye witness testimony’s alone and instead commonly look for alternative evidence, such as DNA sampling or CCTV footage that could be used to collaborate the witness’s testimony before charging someone or making a conviction. Therefore research into the effect of anxiety on EWT has had positive benefits for the criminal justice system by reducing the chances of erroneously convicting the wrong person.
evaluation of the role of anxiety in EWT - reliability and artificiality of research
there’s a lack of consistency when comparing results on real life eye witnesses and research conducted in a lab environment.
Yuille and Cutshall conducted a research into a real life crime, which goes against Lotfus’ findings.
Alternative explanations suggest that this can be explained by the physiological arousal triggering the fight and flight response which actually increases our alertness + improves our memory for the event because we become more aware of cues in the situation.
cognitive interview :
a method of interviewing eyewitnesses to help them retrieve more accurate memories.
Fisher and Geisleman (1992) argued that EWT could be improved if the police uses better techniques when interviewing witnesses.
techniques are based on psychological insights into how memory works
4 techniques for CI + abbreviation
- Recreate the context of the original incident
- Report everything
- Recall events in reverse order
- Change perspectives
C.O.P.E.R
context - mentally recall
order - change order of recall
perspective - different angle
everything
relationship - comfortable atmosphere for interview, like eye contact
Geiselman et al (CI) 1985
argued that police interviews must take into account the characteristics of human memory, including :
1. Misleading information can distort recall
2. Retrieval cues are important, and their absense can lead to inaccuracy
3. Memories are complex, and are made up from different types of memory
Fisher et al 1987
added elements to Cl. the enhanced cognitive interview (ECI)
social dynamics were taken into account, such as when to (or not to) establish eye-contact, ways to reduce anxiety, minimising distractions, asking the witness to speak slowly and to ask open ended questions.
Recreate the context of the original incident
Ask the witness to try and picture the circumstances surrounding the crime. Next ask the witness to think about, or visualise the scene. Ask what the scene looked like, who was present or nearby, where the furniture was,
Standard interview difference :
Police do not ask witness to recreate the context, instead just to free recall the events and then answer questions
what the weather was like, how the witness was feeling at the time or how they reacted to the event
Report every detail
Tell the witness that some people withhold information because the feel it is irrelevant, but they should try and tell the whole story, leaving nothing out. Here the interviewer must be extremely patient and allow the recall as the witness sees it
Standard interviews difference :
The police interview uses the repetition technique, where they repeat the questions needed for the eyewitness testimony, often interrupting the witness
Recall the events in the reverse order
Tell the witness that although it may not feel normal, to try and tell the story in the reverse order, starting at the end of the event or at a significant part of the event. This should help stop witnesses recreating the event in relation to expectations or stereotypes about what normally happens in crimes such as was witnessed
Standard interview difference :
The police would ask for free recall, which would usually end up with a chronological account of events.
change perspectives
instruct the witness to recall the event from a different physical perspective, from a location other than where he or she was during the event. What might they have seen from across the street? What did any of the other witnesses see? What would they have heard? Again this is used to disrupt the personal expectations of what usually happens in a crime (as seen in films etc.)
Standard interviews difference :
More likely to focus only on the witness’ point of view, asking questions about what they saw directly.
Evaluation of the use of CI - supporting evidence
There is supporting evidence for the effectiveness of the cognitive interview.
For example, Kohnken et al (1999) carried out a meta-analysis of 53 studies investigating the Enhanced Cognitive Interview (ECI), and found, on average, a 34% increase in the amount of correct information generated compared with standard police interviews.
Although, caution is required in drawing conclusions about the effectiveness of the Cl as most of these studies were carried out with volunteer participants in a laboratory and not in a ‘real life’ setting.
Despite the limitations of the research, there remains support for the use of Cl over the current police interviewing standards.
Evaluation of the use of CI - economic impact of CI (limitations)
It takes longer and requires more training than the standard interview. Some critics also suggest that some of the procedures are more valuable than others.
For example, Milne and Bull (2002) found that a combination of report everything and context reinstatement produce the most effective reports, which confirmed some of the police officers’ views that some aspects are better than others.
Thus, the economic impact of using the CI must be considered. It may be more viable to only use aspects of the Cl so that time and resources are not being used without good reason to do so.
Evaluation of the use of CI - contradictory research
Although Kohnken et al. (1999) reported an 81% increase in the amount of correct information obtained through the enhanced cognitive interview compared to a standard interview, they also found a significant increase of 61% in the amount of incorrect information or false positives.
This indicates that while the CI may elicit more information, it does not guarantee the accuracy of that information. The presence of false positives poses a challenge for the criminal justice system as they need to exercise caution when interpreting and relying on the information collected through cognitive interviews.
These contradictory findings indicate the need for further research to better understand the conditions under which the cognitive interview may be most effective and to develop strategies for minimising false information.
Evaluation of the use of CI - reliability of research
The research findings about the effectiveness of the CI are reliable.
Geisleman et al (1985) assessed whether the Cognitive Interview is more effective than standard police interviews when interviewing eye-witnesses. They showed police training videos to 89 students. About 48 hours later, the students were interviewed individually by American Law enforcement officers (detectives, CIA investigators and private investigators). The interviewers had either been trained in standard police interviewing techniques or in the new Cognitive Interview Schedule. Each interview was taped and analysed for accuracy of recall.
E.g. 41.5 correct items reported for CI compared to 29.4 for standard interview
The findings from both Konken and Geiselman’s research studies demonstrate consistent results and clearly show that accuracy of EWT is improved by the use of cognitive interview.
As a result, it should be suggested that the CI procedures are used for all EWT in the future.
Johnson and Scott 1976 findings
Ppts later had to pick out the man from a set of 50 photos
49% of the low-anxiety condition correctly identified him
33% of the high-anxiety condition correctly identified him.
The tunnel theory of memory argues that a witness’ attention narrows to focus on a weapon because it is a source of anxiety
Findings Yuille and Cutshall
Ppts were very accurate in their accounts and there was little change in the EWT even after 5 months.
Ppts who reported highest levels of stress were the most accurate in their recall.
This was 88% accuracy compared to 75% for the less-stressed group
Acoustically similar vs semantically similar words
Acoustically : cat, hat sack.
Semantically : small, tiny, short
