Memory isn't a static record of event like photographic or CCTV evidence, it's an active process and there's evident that our previous experiences, stereotypes we hold, emotions we felt at an event, post event information can change our memories and effect the way in which our memory is laid down.
Rattner 1988 reviewed 205 cases of wrongful arrests mistaken EWT 52% of cases
Loftus and Palmer 1974 devised an experiment to find out if leading questions could bias how a witness answers. Film of a car accident to participants, how fast the cars were travelling. The words used in the questioning affected the estimation of speed given, when asked a week later if they'd seen any broken glass, the ones who'd been given the word smashed were most likely to say yes. Subtle changes to wording a question can effect EWT.
Yuille and Cutshall 1986 interviewed 13 witnesses to real life shooting involving a store owner and an armed robber. Store owner was wounded but recovered, robber was shot dead, interviews on witnesses impressively accurate account even months after. Misleading questions had no effect on memory.
Results not consistent with Loftus' findings, they knew the crash wasn't real not emotionally effected. Participants in the lab were expecting to see a film of an event and so would be more prepared than people in real life situations.
Loftus 1975 barn study, see if false information can change original memory. Participants asked about speed of white sports car after watching a film, half asked about a car passing a stop sign, other half about it passing a barn sign. 17% of barn group reported seeing a barn, there'd been no barn in the film. Barn group had added misleading post event information to their original memory.
Lab study, artificial, deception used, participants debriefed afterwards, act the way they think they should.
Misleading information can cause inaccurate recall of events because it leads to phenomenon known as source misattribution.
Tomes and Katz 1997 found that people with general recall for an event are more susceptible to misleading information as are people who score highly on tests of imagery vividness and empathy.
Loftus found that people aren't misled by blatant wrong information, set of slides to participants of a red purse being stolen from a hand bag. Said the purse was brown, not misled when information refers to central rather than peripheral details.
Foster et al 1994 it's possible that participants in experiments are less accurate than real life witnesses because they know inaccuracies won't lead to serious consequences. Tested this possibility in a study where participants were shown a video of a bank robbery and subsequently asked to identify the robber in the identity parade. One group were left to believe that the robbery was a real event, their responses would influence the trial while the second group were told it's a simulation. Identification of the robber was more accurate for the first group. Consequences are an important factor for witnesses.
Improve accuracy recall
Koriat and Goldsmith 1966 witness accuracy can be dramatically increased if tests don't rely on forced choice format and if witnesses are allowed to leave out a question if they feel unsure. Witnesses can produce far more accurate memories if they're given appropriate cues.
Bekerian and Bowers 1983 replicated a study by Loftus et al 1978. Where a car is shown stopping at either a stop or a yield sign, participants are then asked questions which are consistent or inconsistent with what they've seen. In the recognition phase of the study, the participants were presented with the pairs of slides in chronological order. Loftus showed them in any order and their recall was poor. In the replication recall was accurate as a control group who were given non leading information, they concluded that the original memory hadn't been lost for the experiment group. Using slides in the correct order provided enough cues to reactivate the original memory regardless of having been given misleading information after the event.
However, other researchers have failed to replicate this result, so it remains unclear whether the memory trace is destroyed or obscured.
Things that can affect the accuracy of the record at each stage of memory. Encoding- poor viewing conditions, effect of schemas, anxiety and weapons. Storage - misleading information, misattribution errors. Retrieval - leading questions. Age of witness effects everything.
Frederick Bartlett 1932 showed that instead of storing an exact replica of event we store what he terms a reconstructive memory based on our interpretation of events using prior knowledge we've already stored in our memory. This information is available to use stored in discreet entities called schemas.
Schemas help us make sense of the world, if we had to analyse every new event or object from scratch it'd take ages to process the information and would be a waste of resources.
Schemas enables us to process new information according to what we already have stored about previous similar situations and helps us to fill in any gaps in the information available for us.
Brewer and Treyens 1981 investigated the effects of schemas on visual memory. They asked individual participants to wait in a room for 35 seconds. The room was designed to look like an office and contained 61 items, some of which were consistent with an office schema, desk, typewriter, and some of which weren't, skull, brick, pliers. In a later recall test, they found that participants were more likely to recall the typical office items and less likely to recall items inconsistent with an office schema. They also found that errors in recall typically involved substituting schema consistent items, falsely recalling things like pens. Eight participants recalled the bizarre item skull, which shows that we use schemas when encoding information but also pay attention to bizarre or atypical detail.
List 1986 asked people to rate various events in terms of their probability in a shoplifting scenario. She then devised a video showing eight different shoplifting acts, each of which incorporated some of the events rated as high probability and low. She showed the video to a new set of participants and tested their recall a week later. More likely to recall high events than low and that substitution errors made tended to involve high.
Cohen 1993 five ways that schemas can lead to reconstructive memory.
1) we tend to ignore elements of an event that don't fit in with out currently activated schema.
2) we can store then central features of an event without having to store exact detail.
3) we can make sense of what we have seen by filling in missing information.
4) we distort memory of events to fit in with prior expectations.
5) we may use schemas to provide us with a best guess if we can't recall the exact information.
Evidence about the effects of anxiety and stress on the accuracy of EWT is contradictory. Laboratory studies suggest that anxiety can impair recall whereas real life studies often show that the anxiety of an event can enhance recall making memories accurate and long lasting.
Loftus 1979 participants sitting outside a laboratory, believed they were listening to genuine conversation inside the laboratory followed by them witnessing a man leaving. In one condition, participants heard a calm discussion and saw a man with greasy hands and a pen leave. In another condition there was a heated exchange accompanied by the sound of smashing glass and furniture being turned over, then man left holding a bloody knife. Later the group who'd had heard the calm exchange were must better at identifying the man from a series of photographs than the group who'd had a heated exchange. Loftus believed that the anxiety caused by seeing the weapon effected participants ability to identify the man. She called this the weapon effect since the presence the weapon had drawn focus from the face.
Loftus and Burns 1982 participants saw either a film of a violent crime in which a boy was shot in the face, or a non-violent version. Those who'd seen the violent version were less accurate in recalling the details of the crime.
Christianson and Hubinette 1993 questioned 110 witnesses who'd witnesses genuine bank robberies. Some of the witnesses who'd been witnessed were bank employees who'd been directly threatened during the robberies, the rest were onlookers. Victims gave more accurate recall of the event and remembered more difficult details than people who'd been onloookers. This superior recall was evident even after a 15 month interval. This would suggest that people, especially victims, are good at remembering highly stressful events if they occur in real life rather than in the artificial surroundings of a laboratory.
Encoding, Storage and Retrieval
Ceci and Bruck 1993 encoding, believe that children may be inaccurate at providing EWT because they lack the appropriate schemas to help them interpret a situation. However, this could make them more accurate then an adult since without an appropriate schema, they're not susceptible to seeing things which are consistent with a particular schema but weren't actually there during the event.
Thomson 1988 storage, longer the time between the encoding of memory and it's later retrieval, the more likely retrieval is to be inaccurate. The case for both adults and children, children's memories are more affected by a retrieval delay. They type of information stored is also a factor, a storage interval increases, descriptions of people become less accurate then details of action. They type of information stored is also a factor, a storage interval increases, descriptions of people become less accurate then details of action.
Ceci Leichtman 1995 retrieval, children eave out more details than adults but relevant cues help to jog their memory. Children are more susceptible to leading questions than adults so are more likely to recall information implied by the question. They found that if 3 and 6 year old children were given misleading information in questions they incorporated it into their memory.
Poole and Lindsay 2001 children ages 3 to 8 incorporated elements of a story read to them by their parents into their memories of a science demonstration watched earlier. When asked about the source of information, source monitoring, older children were able to remove the post event items. Suggests children who're younger are more susceptible than older children to the effects of misleading post event information.
Geiselman et al 1985 improve accuracy of witness recall by recreating to context, to report every detail, to recall the event in different orders, to change perspectives.
Milne and Bill 2002 context reinstatement and reporting every detail seem to be the most effective combination of element in terms of eliciting accurate recall.
Geiselman 1999 proved to be effective, context reinstatement and reporting every detail with children over the age of 8 but not so useful with children under 6 perhaps because young children fail to understand the instructions.
Fisher 1987 recommends using an enhanced cognitive interview technique in which police actively listen to the witness, minimise distractions, use open ended questions. Encourage the use of imagery and avoid making judgemental comments.
Organisation of information the way we organise information that we wish to remember is central to remembering it effectively. One of the most well known organisation strategy is mnemonics.
This uses verbal rhymes or visual image or organise information such as processes or events which need to be remembered in order.
The more silly or bizarre you make the rhyme the more likely you are to remember it because LTM loves the unusual, the rhyme will be stored with little effort.
Also if you chunk things together it'll take up your STM when you recall it.
Some mnemonic techniques are based on visual imagery, these involve linking a visual image to the information you wish to remember.
One of the most fun visual techniques is called the method of loci, this allows us to remember things like shopping lists by visualising something already stored in LTM and handling the new information from it.
Paivio 1965 visual imagery enhances recall, found that participants were better at recalling concrete nouns than abstract ones. He linked this to the dual coding hypothesis where concrete nouns are encoded twice, first using a verbal code and again using a visual image.
De bene and Moe 2003 found the use of visual imagery to especially help memory when information is presented verbally since conjuring up a visual image can be done whilst holding the word in the articulatory loop and therefore, making use of two separate working memory systems. Studies like these seem to show that visual imagery enhances recall but they have been criticised for lacking realism since it's not very often that we have to learn lists of unrelated words. Having some kind of organisation strategy for remembering the more typical complex information we're more likely to be faced with in real life still seems to improve our recall.
Encoding and Retrieval Stages
Tulving and Thomson 1973 encoding and retrieval strategies, states that when we acquire memories, we encode them with links to the context we're in at the time. The context becomes a retrieval cue which can help recall information stored in LTM.
Tulving and Osler 1968 gave participants lists of words, each of which was paired with cue words, city, dirty. Participants were then asked to recall the original list either by free recall or cued recall. The findings showed that cued recall produced consistently better performance than free recall.
Godden and Baddeley 1975 even the context which learning took place can act as a retrieval cue. They asked divers to learn a list of 40 unrelated words either on land or 15 feet under water. Later, half the divers recalled in their original context whilst the other half recalled in a different context. The findings were that those who recalled in the same context as the one in which learning ha taken place remembered more words. This supports the encoding specificity principles. Information about the context must have been encoded along with the words. These cues weren't available to those who recalled in a different environment, therefore, their recall was poorer.
Smith 1979 gave participants a list of 80 words to learn whilst sitting in a distinctive basement. The following day he tested some of the participants in the same basement, some in an upstairs room and a third group in the upstairs room but asked to imagine they were in the original basement room. The findings were that those in the original context recalled the most words, followed by those who imagined they were in the original context. The worst recall was produced by those in a different context. It's been shown that students simply imagining the original room in which the information was learned can help with retrieval.
State or Mood can effect recall
Godwin et al 1969 state or mood can effect recall, heavy drinkers who learn things in a drunken state are more likely to recall them in a similar state.
Eich 1980 people who learn things when doing marijuana recall them in a similar state.
Ucros 1989 found a moderately strong relationship between mood at the learning and retrieval stage. She also found that mood was more likely to affect real life rather than artificially constructed material and that deep processing, good retention, comes from understanding information semantically.
Craik and Lockhart 1975 more likely to remember material that we have actively processed by interacting with material, called a deep level. They identified three levels on which we can take in information. Structural - what does it look like. Phonological - what does it sound like. Semantic - what does it mean. They argues that taking in information on a structural level involved a very shallow level of processing resulting in a memory trace that isn't very robust and that deep processing, good retention, comes from understand information semantically.
Craik and Lockhart 1972 gave participants a list of words which they had to answer questions requiring shallow, medium deep processing. Then they gave the participants a surprise recall task. Words which have been associated with deep processing on a semantic level were the best remembered. This shows that meaningful interaction with material gives better retention and that the learning is incidental didn't know they were going to be tested, made no special effort to remember the material. Performed well as a control group who made specific effort to remember the words on the list. Activates material stored in LTM and therefore, makes numerous associations which can later act as retrieval cases.
Levels of Processing
Tyler et al 1979 questioned the notion of levels of processing. They believed that the semantic tasks required in processing the information which improved recall. To test this idea, they gave participants two sets of anagrams to solve, difficult and easy. Participants were later given an unexpected recall test. They found that significantly more of the difficult anagram words were recalled and concluded that since all words were processed at the same level semantically, therefore seep level, the better recall in the different anagram group must have been due to the effort put into processing them and not the depth.
Most studies show that the more you interact with the material, the more elaborate and organised you make it, the more likely you are to remember it.