memory Flashcards
coding, capacity and duration ao1
duration - how long information can be stored for
stm - memories do not last long, in order to keep memories for more than a few seconds must be rehearsed. study by peterson and peterson to test stm duration, 24 students given a consonant trigram and asked to count backwards in threes to stop rehearsal then asked to repeat trigram after a period of time, information disappears quickly when not rehearsed, max duration is 18s +lab study - low ecological validity
ltm - the duration of ltm can last a lifetime, study conducted by bahrick, 400 participants asked to remember former classmates by identifying pictures, name recalling and matchng names to pictures, when linking names to faces accuracy was 70% and free recall accuracy was 30%, memories can last a lifetime but cannot always immediately access the information
capacity - measure of the format in which memory is stored
stm - limited to 5-9 items, jacobs serial digit span study, chunking used to improve memory
ltm - unlimited capacity
coding - the form in which information is stored
acoustic coding - stored in terms of the way it sounds
semantic coding - stored in terms of its meaning
visual coding - stored in terms of the way it looks
stm - acoustic
ltm - semantic
sr - modality specific
baddeley made participants write down a sequence of 5 words in four conditions, acoustically similar, accoustically dissimilar, semantically similar, semantically dissimilar. when tested immediately (stm) least accurate was accoustically similar
tested after a while (ltm) least accurate was semantically similar
multi store model ao1
developed by atkinson and shiffrin in 1968, explains how information flows from one memory store to anither and is made up of three unitary stores sensory register, short term memory, long term memory.
environmental stimuli is recieved through the sensed and enters the sensory register, contains stores for each sensory input (iconic, echoic, haptic, olfactory, gustatory), coding is modality specific, capacity is unlimited, duration is extremely short (250 milliseconds).
if attention is payed to this information it enters the short term memory, it is a temporary store for information recieved by sr to be transferred to ltm, stm has a limited capacity of 5-9 items, information in stm is acoustically coded, short duration of 18-30 seconds, without rehearsal information will decay.
if prolonged rehearsal occurs the information will be transferred to the LTM which is a permenant memory store, has an unlimited capacity, lifetime duration, coded semantically. if information is needed from ltm it is retrieved from ltm and transferred back to stm.
multi store model ao3
+ evidence of separate unitary stores came from results of a treatment to a patient known as HM. he had suffered brain damage and underwent an operation to remove his hippocampus from both sides of his brain to reduce the effects of his severe epilepsy. after the operation is was found that though his stm remained intact and unaffected, he was unable to code any new long term memories.
- the msm fails to explain the ability to multitask as if there is only one type of stm then multitasking would not be possible howver we can see people do it everyday such as listening to music and driving. this suggests that the msm is not very applicable to every day life.
- there is also evidence to suggest that stm and ltm are not single stores which contrasts the theroy of the msm, in a patient known as KF, after suffering brain damage from a motorcycle accident he had a severely impaired verbal stm, whilst his visual stm proved to be unaffected. this suggests that only part of the stm was damaged meaning there must be separate components to the stm.
types of long term memory ao1
implicit memories: do not require conscious thought
explicit memories: require conscious thought to recall
episodic memory: explicit, memory for events/episodes, good recall about highly emotional events, allows us to distinguish between real and imaginative events, stored in hippocampus
semantic memory: explicit, memory for facts and general knowledge about the world, to do with recalling already learnt information, begin as episodic then loses association to an event and is generalised, stored in frontal and temporal lobes
procedural memory: implicit, memory for motor skills and actions, muscle memory, acquired through practice and repetition, related to skills that require less conscious thought and more automatic actions to allow focus to be on other things, stored in the cerebellum and motor cortex
differences between long term memory ao1
both episodic and semantic memories are conscious whilst procedural memories are unconscious
using brain scans we can see that different types of memory are stored in different areas of the brain, episodic - hippocampus, semantic - frontal and temporal lobes, procedural - cerebellum and motor cortex
semantic memories are not stored with the memory of where we learnt and encoded the memory, episodic memories are stored with a reference to a time and place
types of long term memory ao3 ( +++- )
+ supported by numerous case studies, ie HM and Clive Wearing, both suffered severe brain damage which impacted their episodic memories however both their procedural and semantic memories remained intact. In Clive Wearings case he suffered a viral brain infection but even after the damage to his memory he could still read and play music brilliantly. this proves that LTM has different stores and damage to one does not necessarily impact the others
+ scientific evidence from brain scans have also shown the existence of different memory stores in different areas of the brain, a study done by Tulving (1989) showed that when the task required the use of the semantic memory there was more brain activation in the frontal and temporal lobes, and when the task required the use of the procedural memory the prefrontal cortex/cerebellum was active
+ by distinguishing between the different stores it allows new memory specific treatments to be developed in real life applications, knowing that episodic memory is a distinct store allows us to find ways to target and improve the episodic memory in people who may have difficulties ( elderly)
- the research conducted into the different types of LTM have all been conducted on individual patients, these case studies may be highly detailed and provide lots of information but they consist of an isolated case of one individual, and therefore could be inaccurate to assume that everyone’s LTM works in the same way, this means that the finding cannot be generalised to the wider population
working memory model ao1
developed by baddeley and hitch who argued the msm was too simplistic and that the stm is not a unitary store and istead had sub stores which are responsible for processing different types of information. they also believed that the stm was an active store that held several pieces of information while being worked on hence the name working memory.
in the wmm there are 4 components - central executive, phonological loop, episodic buffer, visuospacial sketchpad
central executive - drives whole system, allocates data to other components known as slave systems, deals with cognitive tasks like decision making, problem solving, has a limited capacity and so can only do so many things at the same time
phonological loop - deals with word based spoken/written material, split into two, the phonological store (inner ear) which is linked to speech perception and holds speech based info for 1/2 seconds, articulatory process (inner voice) which is linked to speech production and is used to rehearse and store info from phonological store.
visuo-spatial sketchpad - stores and processes information in visual or sptial form, used for navigation, the inner eye, split into two, visual cache which stores visual material about form and colour, inner scribe which handles spatial relationships
episodic buffer - a limited capacity store that integrates information from the central executive, phonological loop and sketchpad and ltm. added later on once it was realised that the model needed a general storage component to operate properly.
working memory model ao3
+ there is also evidence to suggest that stm is made up of multiple sub-stores, in a patient known as KF, after suffering brain damage from a motorcycle accident he had a severely impaired verbal stm, whilst his visual stm proved to be unaffected. this suggests that only part of the stm was damaged meaning there must be separate components to the stm.
+ greater face validity and real world application as accounts for the ability to dual task. as long as the tasks are using two different components (eg one is word based and one is visual) we are able to complete both at once as we are using two different slave systems. howvever we are unable to dual task if both tasks use the same slave system as they have a limited capacity. in barleys study is showed when pps used two different slave systems by following a light and repeat back numbers, they could do this effectively.
- the exact role of the central executive remains quite vague as it is left unclear as to how it works and what it does. some argue that the ce directs attention and allocates inforation to the slave systems however this definition is quite vague. addtionally in the case of EVR when a cerebral tumour was removed he performed well in reasoning tasks but not decision making tasks which are both responsibilites of the ce, this indicates that in fact the ce is much more complex than presented in the wmm
explanation of forgetting - interference ao1
forgetting is the inability to access or recover information that was previously stored in our memories
interference theory states that the reason for forgetting in our long term memory is due to two memories being in conflict which results in the forgetting or distortion of one or both memories, more likely to happen if they are similar
proactive interference - an old memory interferes with the recall of a new memory
retroactive interference - a new memory interferes with the recall of an old memory
explanation of forgetting - interference ao3
- when interference occurs some findings have shown that the loss of information is only temporary, this would mean that one could argue that interference is not a true explanation for forgetting as the information has not been overwritten and still remains in the LTM
- most supporting evidence has been gained from lab studies which use unrealistic material such as lists of words. in a real life setting we would rarely have to learn and recall word lists, therefore studies lake ecological validity and mundane realism, meaning there may be issues when trying to apply the findings to everyday life
+ there is research support to evidence the theory of interference for example McGeoch and McDonald (1931). 6 groups of participants had to learn a list of words until 100% accurate, then 5/6 groups had to learn a new list which varied based on how similar they were to the original words. the lists were synonyms, antonyms, unrelated words, nonsense syllables, three digit numbers, none. participants then asked to recall original list, findings showed those who had the least similar lists did the best at recalling as the memories were not similar so retroactive interference could not take place
explanation of forgetting - retrieval failure due to absence of cues ao1
this theory states that forgetting occurs due to the absence of the appropriate cues, when info is stored the data associated with the information is also stored, and these cues are needed to trigger the memory
encoding specificity principe, tulving 1983 - if the same cues are present at coding and retrieval then the cues will trigger the recall of the info
some cues are linked meaningfully to the information (acronyms)
some cues are not linked meaningfully but may relate to the context in which learning occured (state/context dependant cues)
context dependent cues - recalling information in the same location/environment as where you learnt it will result in better recall than different locations
state dependent cues - recalling information in the same state of mind as when you learnt it will result in better recall than different states of mind
explanation of forgetting - retrieval failure due to absence of cues ao3 (++–)
+ research support by Godden and Baddeley (1975) on context dependent forgetting. 18 divers from a diving club were asked to learn 36 unrelated 2/3 syllable words and recall them in 4 different conditions. the conditions were learn on beach recall on beach, learn on beach recall under water, learn under water recall on beach, learn under water recall under water. the results showed that recall was better when the contexts were the same showing that the context in which you learn and recall does have an impact on retrieval of information
+ used in real life applications for example the cognitive interview where individuals are asked to recall the context of the scene they are in (context reinstatement) in order to aid their memory recall, therefore showing that research into forgetting is successful in real life applications
- retrieval cues do not always work as our learning is related to a lot more than just cues, additionally the research studies focus of the impact of cues of recalling word lists which lacks mundane realism meaning this explanation may not be accurate in a real world context
- in some situations we can see context and state having no mpact of the retrieval of information, for example during exams, it is highly unlikely that students would have learnt the information that they are trying to recall in the exam hall however they are still able to recall it, additionally they are likely to be in different states of mind as they may be quite nervous when recalling but calm when learning. from this we can see that in some instances retrieval cues may have little to no impact on one’s ability to recall information
eyewitness testimony ao1
refers to the account given by people of an event they have witnessed based on their memory of the incident, used as evidence to help identification of a perpetrator or find details of a crime
effect of misleading information on eye witness testimony ao1
a leading question is a question that suggests to the witness what the desired answer is or leads them to give a certain answer due to phrasing
a study done by loftus and palmer (1974) where 45 students were shown a video of a car accident and were then asked about the speed of the cars on impact however different groups were asked the same question of “how fast were the cars going when they hit each other?” but the verb “hit” was switched to smashed, bumped, collided, contacted. the results showed that the verb change had a significant effect on the speed estimates, the verb contacted gave the lowest mean of 31.8, whilst the verb smashed gave the highest mean of 40.5mph.
a follow up study was completed using the same condition of altering the verb but instead the participants were asked if there was any broken glass in the video, there was none but those who were asked using the verb smashed were more likely to report seeing broken glass, showing that leading questions have the ability to alter a victim’s memory of a situation
post event discussion is when witnesses to an event dicuss what they have experienced. it can lead to memory contamination (the memory has been contaminated by misinformation discussed with other witnesses), and memory conformity (a desire for social approval caused witnesses to take information from the testimony of other witnesses in order to be right/liked). effects of post event discussion was tested by gabbert et al where participants all watched videos of different angles of the same events with each angle showing unique details which would not be seen in the others, then participants were put into pairs and encouraged to discuss the event before individually recalling the event, findings showed that 71% of witnesses recalled details they would have been unable to see in their video but that they had learnt in the discussion with their partner
effect of misleading information of eye witness testimony ao3
+ most studies that evidence these theories were conducted within well-controlled lab settings meaning any extraneous variables could be controlled to reduce their effect on the results and we can be sure that any findings are due to the impact of misleading information. additionally lab studies ensure reliability within the results as they can be easily replicated with standardised procedures.
+ this research into misleading information has application in real life and it is able to show the effect of leading questions and post event discussion on eye witness testimony. this allows police to understand how fragile the memory is and that care should be taken when phrasing questions when interviewing witnesses to be sure they are not leading them to an answer. police should also take care to ensure that co-witnesses are prevented from discussing their testimonies to ensure that their testimonies are not contaminated .
- a weakness of these studies though is that almost all of these studies had been conducted by participants watching a video or watching a staged event which is very different to seeing an event happen in real life causing participants to be less motivated to be accurate, this could mean that the results are invalid and would not be accurate if the studies were conducted after participants had seen a real event, additionally as they are watching a video there is little to no anxiety but anxiety would be present in a real situation, it has been proven that an increase in anxiety during the situation does increase the recall and the accuracy of the recall of an event.
effect of anxiety on eye witness testimony ao1
anxiety is a state of apprehension, uncertainty and fear which can impair both physical and psychological functioning and as a result can often have emotional and physical effects on eye witnesses and their testimony.
according to yerkes and dodson the relationship between emotional arousal and performance takes the shape of an inverted ‘u’ where performance will increase with stress up until a certain point and after that point performce decreases drastically. the law was applied to the case of eye witness testimony to say low anxiety causes low recall accuracy (no pressure/consequences), memory becomes more accurate as anxiety increases but too much anxiety and the recall suffers a drastic decline in accuracy
one situation where anxiety becomes too high that recall accuracy suffers is when the weapon focus effect occurs, this is when a witness who witnesses a violent crime involving a weapon shows a slective attention bias towards the weapon and can often describe the weapon in great detail but recall about the criminal is low.
a study in 1976 by Johnson and Scott investigated the weapon focus effect by asking participants to sit outside a laboratory and they either heard one of two conditions
condition 1 - friendly conversation and man emerging with a pen and grease on hands (low anxiety)
condition 2 - argument with smashing glass, overturned furniture and man with a blood stained paper knife (high anxiety)
participants were then asked to identify the man from 50 photos
findings showed that there was 49% accuracy in identifying the man with the pen however there was only 33% accuracy in identifying the man with the knife. this shows that anxiety has affected the recall as the participants in the high anxiety condition were focused on the weapon that posed a threat rather than the face of the man resulting in lower accuracy.
effect of anxiety on eye witness testimony ao3
- numerous ethical guidelines were violated by this study, the participants were deceived about the nature of this experiment and additionally were not protected from psychological harm. these participants were led to believe that they were exposed to a murder scene which is likely to cause participants extreme distress especially if by chance they had experienced something similar before.
- weapon focus may not always be caused by anxiety, Pickel proposed that the reduced accuracy did not come from anxiety but rather surprise. she conducted a study where participants watched a thief enter a salon holding one of 4 weapons, scissors, handgun, wallet, whole raw chicken, based on their level of threat and surprise. the findings showed that identification was least accurate in the high surprise condition of the chicken rather than the high threat condition of the scissors or handgun.
- the Yerkes Dodson Law is too simplistic as anxiety is difficult to define and measure accurately due to its many elements (cognitive, behavioural, emotional, physical). it is hard to measure anxiety and compare it to performance. additionally personality characteristics may come into play with accuracy in recall. some individuals have better recall when they are in an anxious state meaning there are individual differences in the effect of anxiety levels and this explanation is too simplistic
cognitive interview ao1
Geiselman et al (1985) developed the cognitive interview to improve police techniques and obtain more accurate information from eyewitnesses
it consisted of 4 stages
context reinstatement - recreate an image of the situation and the environment in order to act as context dependant retrieval cues
report everything - encourages witness to recall all details about the vent even if seemingly unimportant, helps to highlight overlooked details and trigger other memories
recall from a changed perspective - witness asked to recreate the situation from different viewpoints (eg what other witnesses might have seen) to provide a holistic view of the event and and reduce the influence of schemas
recall in a changed order - witness recalls the scene in a different chronological order, in order to verify the accuracy of the account and highlight any missed details
additional guidelines were added by Fisher (1987)
- encourage the witness to relax and speak slowly
- reduce the witnesses anxiety
- avoid distractions
- use open ended questions
- offer comments to help clarify
cognitive interview ao3 (++–)
+ research support to evidence that the cognitive interview not only generates more information but more accurate information. gieselman et al (1986) staged a situation where an intruder wearing a blue rucksack steals a slide projector from a classroom, 2 days later participants were questioned either using standard interviews or the cognitive interview, early on participants were asked a leading question, then later were asked about the same thing but in an open ended question, findings showed that those in the cognitive interview were less likely to be affected by the leading question
+ a meta analysis of 53 studies was conducted by Kohnken et al (1999) which showed on average, an increase of 34% in the amount of correct information generated in a cognitive interview compared to a normal interview
- the cognitive interview can be very time consuming and is quite expensive, conducting a cognitive interview takes a lot of time which is not always available to the police, additionally in order to conduct a cognitive interview, the interviewer has to receive a lot of training which means more money and time to introduce this technique
- gieselman’s study alongside others that evidence the effectiveness of the cognitive interview have all been coonducted as lab studies, in the case of gieselman his study consisted of participants recalling a staged crime however watching a real crime is very different and is likely to induce different emotions which may affect the amount of information recalled, therefore findings cannot be generalised to every day life
