MEMORY

cognitive interview

cognitive interview

a method of interviewing eyewitnesses to help them retrieve more accurate memories using four main techniques based on psychological knowledge of human memory - report everything, reinstate the context, reverse the order and change perspective

Fisher and Geiselman

argued that eyewitness testimony could be improved if the police used better techniques when interviewing witnesses and recommended they should be based on psychological insights into how memory works (CI)

report everything (CI)

witnesses are encouraged to include every detail of the event, even though it may seem irrelevant or the witness doesn’t feel confident about it - may trigger other important memories.

reinstate the context (CI)

the witness should return to the original crime scene ‘in their mind’ and imagine the environment (weather, surroundings) and their emotions - related to context-dependent forgetting

reverse the order (CI)

events should be recalled in a different order from the original sequence - this is done to prevent people reporting their expectations of how the event must have happened rather than reporting the actual events and prevents dishonesty

change perspective (CI)

witnesses should recall the incident from other people’s perspectives (how it would appeared to other witnesses or perpetrator) to disrupt the effect of expectations and the effect of schema on recall

effect of schema on recall

the schema you have for a particular setting generate expectations of what would have happened and it is the schema that is recalled rather than what actually happened

the enhanced cognitive interview

fisher et al developed some additional elements of the CI to focus on the social dynamics of interaction - like when to establish eye contact etc. - includes ideas such as reducing eyewitness anxiety, minimising distractions, getting the eyewitness to speak slowly and asking open-ended questions

strength of the CI: support for effectiveness

• evidence it works

• Köhnken et al: meta-analysis combining data from 55 studies comparing the CI/ECI with the standard police interview

• CI = 41% increase in accurate information compared to standard interview

• only 4 studies in the analysis showed no difference

• effective technique helping witnesses recall info stored in memory but not immediately accessible

counterpoint of the CI

• Köhnken et al: increase in the amount of inaccurate info recalled by participants

• especially in the ECI = more incorrect details than the CI

• CI may sacrifice quality of EWT in favour of quantity

• police should treat evidence with caution

limitation of the CI: some elements may be more useful

• not all elements are equally effective/useful

• Milne + Bull: each of the four techniques used alone produced more information than the standard police interview.

• found using a combination of report everything and reinstate the context produced better recall than any of the other elements or combinations

• confirmed police suspicions that some aspects are more useful than others

• doubts credibility of overall CI

limitation of the CI: time-consuming

• police may be reluctant to use CI as it takes ore time and training than standard police interview

• more time is needed to establish rapport with a witness and allow them to relax

• the CI requires special training and many forces don’t have the resources to provide more than a few hours

• complete CI isn’t a realistic method for police to use

anxiety’s negative effect on recall

anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse

weapon focus

the effect of the presence of a weapon which creates anxiety - this leads to a focus on the weapon, reducing a witness’s recall for other details of the event

Johnson and Scott procedure

• participants believed they were taking part in a lab study

• low anxiety condition: while seated in a waiting room participants heard a casual conversation in the next room and saw a man walk past carrying a pen with grease on his hands

• high anxiety condition: overheard a heated argument, the sound of breaking glass. a man walked out holding a knife covered in blood

Johnson and Scott findings

• participants later picked out the man from a set of 50 photos.

• 49% who saw the man carrying the pen could identify him.

• only 33% of those who saw the man holding the knife could identify him

tunnel theory of memory

argues that people have enhanced memory for central events - weapon focus as a result of anxiety can have this effect

anxiety’s positive effect on recall

witnessing a stressful event creates anxiety through physiological arousal within the body - the fight or flight response is triggered, increasing alertness. this may improve memory for the event as we become more aware of cues in the situation

Yuille and Cutshall procedure

• study of an actual shooting in a guns shop in Canada - the shop owner shot a thief dead

• there were 21 witnesses - 13 took part.

• interviewed 4/5 months after the incident and these interviews were compared to original police interviews at the time of the shooting

• accuracy was determined by the number of details reported in each account

• witnesses were asked to rate how stressed they felt at the time of the incident and whether they had any emotional problems since then

Yuille and Cutshall findings

the witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after 5 months - some details were less accurate like recollection of colours

participants who reported the highest stress levels were most accurate compared to the less-stressed group (88% compared to 75%)

anxiety doesn’t have a detrimental effect and may enhance memory

Deffenbacher

reviewed 21 studies of EWT and noted contradictory findings on the effects of anxiety and used the Yerkes-Dodson Law to explain the findings

yerkes-dodson law

inverted u: when we witness a crime we become emotionally and physiologically aroused (fight/flight). lower levels of anxiety produce lower levels of recall accuracy, and then memory becomes more accurate as the level of anxiety increases. there is an optimal level of anxiety, which is the point of maximum accuracy, if a person experiences any more arousal then their recall suffers a drastic decline

performance will increase with stress, but only to a certain points, where it decreases drastically

limitation of anxiety affecting EWT accuracy: unusualness not anxiety

• Johnson and Scott study may not have tested anxiety

• participant may have focused on the weapon because they were surprised, not scared

• Pickel: experiment using scissors, a handgun, a wallet or a raw chicken as the hand-held items in a hairdressing salon video

• EW accuracy was significantly poorer in the high unusualness conditions (chicken and handgun)

• weapon focus effect is due to unusualness rather than anxiety and tells us nothing about the effects of anxiety

strength of anxiety affecting EWT accuracy: support for negative effects

• evidence supports the view anxiety has a negative effect on accuracy of recall

• Valentine + Mesout study supports the research on weapon focus, finding negative effects on recall

• researchers used an objective measure (heart rate) to divide participants into high- and low- anxiety groups

• anxiety clearly disrupted the participants’ ability to recall details about the actor in the London Dungeon’s Labyrinth

• high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event

strength of anxiety affecting EWT accuracy: support for positive effects

• Christianson and Hübinette interviewed 58 witnesses to actual bank robberies in Sweden

• some witnesses were directly involved and some were indirectly involved.

• researchers assumed those directly involved would experience the most anxiety

• they found recall was more than 75% accurate across all witnesses

• direct victims were even more accurate

• findings from actual crimes confirm anxiety doesn’t reduce accuracy of recall

counterpoint of anxiety affecting EWT accuracy

• Christianson and Hübinette interviewed participants several months after the event

• researchers had no control over what happened to their participants in the intervening time

• effects of anxiety may have been overwhelmed by other factors (post-event discussion)

• lack of control over confounding variables may be responsible for these findings, invalidating their support

eyewitness testimony (EWT)

the ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed. accuracy of EWT can be affected by factors such as misleading information and anxiety

misleading information

incorrect information given to an eyewitness usually after the event - it can take many forms, such as leading questions and post-event discussion between co-witnesses

leading question

a question which, because of the way it is phrased, suggests a certain answer

post-event discussion

occurs when there is more than one witness to an event - witnesses may discuss what they have seen with co-witnesses or with other people, this may influence the accuracy of each witness’s recall of the event

Loftus and Palmer’s research on leading questions

arranged for 45 students to watch film clips of car accidents and then asked questions about the accident.

what was the leading question in Loftus and Palmer’s research?

‘About how fast were the cars going when they hit each other’

• there were 5 group of participants and each was given a different verb in the critical question

what were the different verbs in Loftus and Palmer’s leading question?

hit, contacted, bumped, collided, smashed

findings of Loftus and Palmer’s research

• the mean estimated speed was calculated for each group

• the verb contacted had a mean of 31.8 mph

• the verb smashed had a mean of 40.5 mph

• the leading question biased the eyewitness’s recall of an event

what were the two explanations as to why leading questions affect EWT?

the response-bias explanation and the substitution explanation

response-bias explanation

suggests that the wording of the question has no real effect on the participants’ memories but just influences how they decide to answer - when a participant gets a leading question with the word smashed this encourages them to choose a higher speed estimate

substitution explanation

proposes that the wording of a leading question changes the participant’s memory of the film clip

Loftus and Palmer’s second experiment

participants who originally heard smashed were later more likely to report seeing broken glass than those who heard hit - the critical verb altered their memory of the incident (substitution explanation)

Gabbert’s research on post-event discussion

• studied participants in pairs and each participant watched a video of the same crime,

• filmed from different points of view so they could see elements in the event that the other couldn’t (only one participant could see the title of a book)

• both participants then discussed what they had seen before completing a test of recall

Gabbert et al’s findings

found 71% of participants mistakenly recalled aspects of the event that they didn’t see in the video but had picked up in discussion

in the control group, with no PED, was 0% - memory conformity

what were the two explanations as to why post-event discussion affects EWT?

memory contamination and memory conformity

memory contamination

when co-witnesses to a crime discuss it with each other, their eyewitness testimonies may become altered or distorted because they combine misinformation from other witnesses with their own memories

memory conformity

Gabbert et al: concluded that witnesses often go along with each other, either to win social approval or because they believe the other witnesses are right and they are wrong - the actual memory is unchanged

strength of misleading information affecting EWT accuracy: real-world application

• research into misleading information has important practical uses in the criminal justice system

• Loftus: believes leading questions can have such a distorting effect on memory that police officers need to be careful about how they phrase their questions when interviewing eyewitnesses

• psychologists are sometimes asked to act as expert witnesses in court trials and explain the limits of EWT to juries

• psychologists can improve the legal system by protecting innocent people from faulty convictions based on unreliable EWT

counterpoint of misleading information affecting EWT accuracy

• practical applications of EWT may be affected by issues with research

• Loftus + Palmer’s participants watched film clips in a lab - very different from witnessing a real event

• Foster et al: what eyewitnesses remember has important consequences in the real world, but participant’s responses in research don’t matter in the same way

• research participants are less motivated to be accurate

• researchers are too pessimistic about the effects of misleading information

limitation of misleading information affecting EWT accuracy: evidence against substitution

• EWT is more accurate for some aspects of an event than for other

• Sutherland + Hayne: showed participants a video clip, when participants were later asked misleading questions, their recall was more accurate for central details of the event than for peripheral ones

• the participants’ attention was focused on. central features of the event and these memories were relatively resistant to misleading information

• original memories for central details survived and weren’t distorted - not predicted by the substitution explanation

limitation of misleading information affecting EWT accuracy: evidence challenging memory conformity

• there is evidence that PED actually alters EWT

• Skagerberg + Wright: showed participants film clips - two versions (hair was dif colour)

• participants discussed the clips in pairs, each having seen different versions

• they often didn’t report what they had seen in the clips but a ‘bend’ of the two - medium brown

• suggests memory is distorted through contamination rather than memory conformity

retrieval failure

a form of forgetting - occurs when we don’t have the necessary cues to access memory, the memory is available but not accessible unless a suitable cue is provided

cue

a ‘trigger’ of information that allows us to access a memory, such cues may be meaningful or may be indirectly linked by being encoded at the time of learning. indirect cues may be external or internal

context-dependent forgetting

recall depends on external cue (e.g. weather or a place)

state-dependent forgetting

recall depends on internal cue (e.g. feeling upset, being drunk)

Tulving

reviewed research into retrieval failure and discovered a consistent pattern to the findings - he summarised this in the encoding specificity principle

encoding specificity principle (ESP)

states that a helpful cue has to be both (1) present at encoding and (2) present at retrieval.

if the cues available at encoding and retrieval are different there will be some forgetting

types of cues

some cues are encoded at the time of learning in a meaningful way (mnemonic techniques) others are encoded in a non-meaningful way

Godden and Baddeley’s research on context-dependent forgetting

• studied deep-sea divers who work underwater to see if training on land helped or hindered their work underwater.

• the divers learned a list of words either underwater or on land and then asked to recall the words either underwater or on land

what were the four conditions in Godden and Baddeley’s research?

• learn on land - recall on land

• learn on land - recall underwater

• learn underwater - recall on land

• learn underwater - recall underwater

findings of Godden and Baddeley’s research

accurate recall was 40% lower in the non-matching conditions - they concluded that the external cues available at learning were different from the ones available at recall and this led to retrieval failure

Carter and Cassaday’s research on state-dependent forgetting

• gave antihistamine drugs to their participants (had a mild sedative effect making the participants slightly drowsy)

• this creates and internal physiological state different from the normal state of being awake

• participants had to learn lists of words and passages of prose and then recall the information

what were the four conditions in Carter and Cassaday’s research?

• learn on drug - recall on drug

• learn on drug - recall not on drug

• learn not on drug - recall on drug

• learn not on drug - recall not on drug

findings of Carter and Cassaday’s research

in conditions where there was a mismatch between internal state at learning and recall, performance on the memory test was significantly worse

when cues are absent then there is more forgetting

strength of research into retrieval failure: real-world application

• retrieval cues can help to overcome some forgetting in everyday situations

• cues may not have a strong effect on forgetting, but Baddeley suggests they are worth paying attention to

• when having trouble remembering something, it is worth making the effort to recall the environment in which you learned it first

• e.g. going into a room to get something, forgetting in the other room, going back to the original room and remember it again

• research can remind us of strategies we can use in the real world to improve recall

strength of research into retrieval failure: research support

• there is a range of research that supports the retrieval failure explanation

• studies by Godden and Baddeley and Carter and Cassaday are two examples because they show a lack of relevant cues at recall can lead to context-dependent and state-dependent forgetting in everyday life

• memory researchers Eysenck and Keane argue that. retrieval is perhaps the main reason for forgetting from LTM

• shows retrieval failure occurs in real-world situations as well as labs

counterpoint of research into retrieval failure

• Baddeley argues that the context effects are not very strong, especially in everyday life

• different contexts have to be very different before an effect is seen

• it would be hard to find an environment as different from land as underwater

• learning something in one room and recalling it in another is unlikely to result in much forgetting because these environments are generally not different enough

• retrieval failure due to lack of contextual cue may not explain everyday forgetting

limitation of research into retrieval failure: recall versus recognition

• context effects may depend on the type of memory being tested

• Godden and Baddeley replicated their underwater experiment but used a recognition test instead of recall

• participants had to say whether they recognised a word read to them from a list, instead of retrieving it for themselves

• there was no context-dependent effect - performance was the same in all four conditions

• suggests that retrieval failure is a limited explanation for forgetting

• only applies when a person has to recall information rather than recognise it

interference

forgetting because one memory blocks another, causing one or both memories to be distorted or forgotten

proactive interference (PI)

forgetting occurs when older memories disrupt the recall of newer memories - the degree of forgetting is greater when the memories are similar

retroactive interference (RI)

forgetting occurs when newer memories disrupt the recall of older memories already stored - the degree of forgetting is greater when the memories are similar

interference in LTM

• interference has been proposed mainly as an explanation for forgetting in LTM - once information has reached LTM it is more or less permanent. -

• forgetting of LTMs is most likely because we can’t get access to them even though they are available

• interference between memories makes it harder for us to locate them

McGeoch and McDonald’s research on the effects of similarity

• studied the effect of retroactive interference by changing the amount of similarity between two sets of materials.

• participants had to learn a list of 10 words until they could remember them with 100% accuracy, then they learned a new list

• there were six groups who had to learn different types of new lists

what were the groups in McGeoch and McDonald’s study?

• Group 1 → synonyms

• Group 2 → antonyms

• Group 3 → words unrelated to the original ones

• Group 4 → consonant syllables

• Group 5 → three-digit numbers

• Group 6 → no new list (control)

findings from McGeoch and McDonald’s study

when participants were asked to recall the original list of words, the most similar material (synonyms) produced the worst recall → shows that interference is strongest when the memories are similar

explanation of the effects of similarity on PI

previously stored information makes new similar information more difficult to store

explanation of the effects of similarity on RI

new information overwrites previous similar memories because of the similarity

strength of research into interference: real world interference

• there is evidence of interference effects in everyday situations

• Baddeley and Hitch asked rugby players to recall the names of the teams they had played against during a rugby season

• the players all played the same time interval but the number of intervening games varied because some players missed matches due to injury

• players who played the most games (most interference) had the poorest recall

• shows interference can operate in real world situations

• increases the validity of interference theory

counterpoint of research into interference

• it is unusual for interference to occur in everyday situations

• conditions necessary for interference to occur are rare - unlike lab studies where the high degree of control means a researcher can create ideal conditions for interference

• two memories have to be fairly similar in order to interfere with each other - may happen occasionally but not often

• forgetting might be better explained by other theories

limitation of research into interference: interference and cues

• interference is temporary and can be overcome by using cues

• Tulving and Psotka: gave participants lists of words organised into categories, one list at a time

• recall averaged about 70% for the first list, but became progressively worse as participants learnt each additional list (PI)

• at the end of the procedure the participants were given a cued recall test - they were told names of categories and recall rose again to 70%

• shows interference causes a temporary loss of accessibility to material still in the LTM

strength of research into interference: support from drug studies

• there is evidence of retrograde facilitation

• Coenen + van Luijtelaar: gave participants a list of words and later asked them to recall the list - assuming the intervening experiences would act as interference

• they found when a list of words was learned under the influence of diazepam, recall one week later was poor (compared to a placebo control group)

• when a list was learned before the drug was taken, later recall was better than placebo

• the drug improved recall of material learned beforehand

• Wixted: suggests that the drug prevents new information reaching parts of the brain involved in processing memories so it can’t interfere retroactively with information already stored

• forgetting can be due to interference

central executive

monitors incoming data, focuses and divides our limited attention and coordinates the 3 subsystems to tasks. it has limited processing capacity and doesn’t store information

phonological loop

deals with auditory information (acoustic coding) and preserves the order in which the information arrives. includes written and spoken material. is divided into the phonological store and articulatory process

phonological store

stores the words you hear

articulatory process

allows maintenance rehearsal (repeating sounds to keep them in working memory). the capacity of this loop is believed to be two seconds’ worth of what you can say

visuo-spatial sketchpad

stores visual and spatial information. has a limited capacity of about 3/4 objects. Logie subdivided the VSS into the visual cache and the inner scribe

visual cache

stores visual data

inner scribe

records the arrangement of objects in the visual field

episodic buffer

• a temporary store for information, integrating the visual, spatial, and verbal information processed by other stores and maintaining a sense of time sequencing.

• is a storage component of the central executive and has a limited capacity of about four chunks. it links working memory to LTM and wider cognitive processes like perception

• added to the model by Baddeley in 2000

working memory model (Baddeley and Hitch 1974)

• an explanation of how STM is organised and how it functions.

• it suggests that STM is a dynamic processor of different types of information using subunits co-ordinated by a central decision making system

• is concerned with the mental space that is active when we are temporarily storing and manipulating information

• consists of four main components, each of which is qualitatively different in terms of coding and capacity

strength of the WMM: clinical evidence

• support from Shallice and Warrington’s case study of patient KF

• after his brain injury, KF had poor STM ability for auditory information but he could process visual information normally

• his immediate recall of letters and digits was better when he read them than when they were read to him

• KF’s phonological loop was damaged but his VSS was intact

• supports the existence of separate visual and acoustic memory stores

counterpoint of the WMM

• it’s unclear whether KF had other cognitive impairments which might have affected his performance on memory tasks

• his injury was caused by a motorcycle accident - the trauma involved may have affected his cognitive performance quite apart from any brain injury

• challenges evidence that comes from clinical studies of people with brain injuries that may have affected many different systems

strength of the WMM: dual-task performance

• studies of dual task performance support the separate existence of the VSS

• when Baddeley et al’s participants carried out a visual and verbal task at the same time, their performance on each was similar to when they carried out the tasks separately

• when both the tasks were visual/verbal performance on both declined

• both visual tasks compete for the same subsystem (VSS) whereas there is no competition when performing a visual and verbal task together

• shows there must be a separate subsystem that processes visual input and one for verbal processing

limitation of the WMM: nature of the central executive

• there is a lack of clarity over the nature of the central executive

• Baddeley: ‘the central executive is the most important but least understood component of working memory

• the CE needs to be more clearly specified than just ‘attention’

• some psychologists believe the CE may consist of separate subcomponents

• CE is an unsatisfactory component and challenges the integrity of the WMM

Tulving’s types of LTM

first cognitive psychologist to realise the MSM view of LTM was too simplistic - he proposed there are three LTM stories containing different types of information (episodic, semantic and procedural)

episodic memory

• LTM store of our ability to recall events from our lives.

• they are time-stamped, and store information about how events relate to each other in time.

• includes several elements (people/places/objects) that are interwoven to produce a single memory

• you have to make a conscious effort to recall episodic memories

semantic memory

• LTM store for our knowledge of the world. includes facts and our knowledge of what words and concepts mean.

• they need to be recalled deliberately. is less personal and constantly being added to

• is less vulnerable to distortion and forgetting than episodic memory

procedural memory

• LTM store for our knowledge of how to do things

• includes our memories of learned skills

• we recall these memories without making a conscious or deliberate effort

strength of types of LTM: clinical evidence

• there is supporting evidence from the case studies of HM and Clive Wearing

• Episodic memory in both men was severely impaired due to brain damage

• their semantic memories were unaffected - they still understood the meaning of words

• HM could not recall stroking a dog half an hour earlier but he didn’t need the concept of a dog explained to him

• Procedural memories were also intact - both knew how to read music, sing and play the piano

• supports Tulving’s view there are different memory stores

counterpoint of types of LTM

• clinical studies of people with brain injuries are not perfect

• they lack control of variables

• brain injuries experienced by participants were usually unexpected - the researcher had no way of controlling what happened to the participant before or during the injury

• researcher has no knowledge of the individual’s memory before the damage so it’s difficult to judge how much worse it is afterwards

• lack of control limits what clinical studies can tell us

limitation of types of LTM: conflicting neuroimaging evidence

• there are conflicting research findings linking types of LTM to areas of the brain

• Buckner + Peterson: reviewed evidence regarding the location of semantic and episodic memory

• they concluded that semantic memory is located in the left side of the PFC and episodic memory on the right

• other research links the left PFC with the encoding of episodic memories and the right PFC with episodic retrieval

• challenged neurophysiological evidence to support types of memory as there is poor agreement on where each type might be located

strength of types of LTM: real world application

• understanding types of LTM allows psychologists to help people with memory problems

• as people age they experience memory loss,

• research has shown this is specific to episodic memory (harder to recall memories of personal events/experiences that occurred recently but past episodic memories stay intact)

• Belleville et al: intervention to improve episodic memories in older people, the trained participants performed better on a test of episodic memory after training than a control group

• distinguishing between types of LTM enables specific treatments to be developed

multi-store model (MSM)

a representation of how memory works in terms of three stores: sensory register, STM and LTM. it describes how information is transferred from one store to another, what makes some memories last and what makes some memories disappear