memory

• eyewitness testimony


  the ability of people to remember the details of event which they have observed
• leading questions


  a question that suggests a certain answer due to the way it's phrased
• Loftus and Palmer


  investigated the role of leading questions in recall

  - 45ppts watched clips of car accidents in a lab setting

  - they were then asked the same leading question but with different synonyms to describe the speed of the car: smashed, collided, bumped, contacted.

  - the mean estimated speed was highest for 'smashed' and lowest for 'contacted". this shows that leading questions an bias EWT.

  
  

  - a follow up study a week later asked the ppts if they saw any broken glass (even though there wasn't any) and the ppts who heard the word 'smashed' were more likely to report seeing broken glass than those who heard 'hit
• post-event discussion


  when co-witnesses to an event/crime discuss the details of it with each other meaning their testimonies become contaminated by the combination of information from other witnesses with their own memories
• Gabbert et al.


  - placed ppts into pairs and each ppt watched a video of the same crime but they were filmed from different points of view meaning both observed elements that their partner didn't

  - after watching the clip, the pairs discussed what they observed before being interviewed

  - 71% of ppts mistakenly recalled elements of the clip that they hadn't directly observed but were discussed by their partner

  
  

  -internal validity increased with the use of a control group who were tested individually and didn't discuss

  - they had 0% false recall of the clip they had watched.

  
  

  evidence that post-event discussion affects information recall and suggests that witnesses often go along with each other to gain social approval which is called memory conformity
• the bunny effect


  Loftus aimed to have participants share their childhood experience with Bugs Bunny at Disneyland even though that is an impossible occurrence as Bugs is a Warner Brothers character

  - ppts evaluate a fake ad for Disneyland which included a photo of Bugs Bunny on it and then they were asked questions about the colour and layout of the ad, and then their childhood experience to Disneyland and which characters they met

  - many ppts recalled meeting Bugs Bunny and went into detail about the encounter when questioned about it

  - this provides support for the influence of leading questions on a person's memory recall
• artificial tasks to measure leading questions and post-event discussion


  watching a video is arguably less emotionally arousing than witnessing real incidents and some evidence suggest that emotional arousal can improve the accuracy of EWT

  - questions how much lab studies can tell us about real life EWT

  - ppts in Loftus and Palmer's study watched the car accident from start to finish and in a real life situation witnesses may only see part of the crash, and from one particular perspective

  - decreases the validity of the results from lab studies into EWT
• individual differences


  evidence has shown that older people have less accurate recall than younger people when giving EWT- age groups 18-25 and 35-45 were more accurate than people 55-78 years oldhowever,all age groups were most accurate when identifying people their own age (age bias)- age can have an impact on the accuracy of EWT
• real-life application of leading questions


  the consequences of inaccurate EWT can be serious in settings such as criminal investigations

  - Loftus believed that leading questions could have such a distorting effect on memory that police officers need to be very careful with how they phrase words and sentences

  this criticism led to the introduction of the cognitive interview
• reinstate the context - cog interview


  witness is asked to return to the crime scene in their minds

  - "think about the day...what you had been doing...what was the weather like"

  - links to context-dependent forgetting which suggests that we recall more if the context in which we recall and retrieve the information are the same
• report everything - cog interview


  witnesses encouraged to report every detail even if it seems insignificant to them

  - small details may trigger more important memories
• change the order - cog interview


  witnesses asked to recall the story in a different chronological order to the original sequence (middle or end to the beginning)

  - stops people reporting their schemas (expectations) of what's going to happen rather than the actual events

  - catches people out if they're being dishonest as it's much harder to lie in reverse order)
• change the perspective - cog interview


  witnesses asked to recall the incident from other peoples perspectives

  - disrupts the effects of schemas on recall

  - "how would this of looked to other witnesses?"
• Geiselamn et al.


  compared the cognitive interview with a standard interview technique on 51 volunteer participants

  - ppts watched two films of violent crimes and were interviewed 48 hours later using either a standard or cognitive interview

  - significant increase in the number of correct items recalled using the cognitive interview, and a small decrease in made up items recalled

  - cognitive interview is effective in increasing the accuracy of EWT
• Köhnken et al.


  meta-analysis of 53 studies- cognitive interview increased recall on average by 34% compared to the standard interview- providing evidence that the cognitive interview is effective and has validityHowever,most of the studies involved were conducted on college students in a laboratory setting therefore the sample lacks population validity as the students aren’t representative of the population, and lacks mundane realism due to the artificial setting
• Fisher et al.


  trained detectives from the Miami PD to use the cognitive interview and interview victims or witnesses of crime

  - compared findings to a control group of officers who used the standard interview

  - interviews were recorded and the total number of statements was scored

  - a second eyewitness then confirmed or denied the statements

  - cognitive interview produced 90% accuracy overall, 46% more accurate recall compared to the standard

  - evidence for the effectiveness of the cognitive interview as it produces higher recall and less errors compared to the standard interview. Additionally, the study has high external validity as real police officers and witnesses were used
• real-world application of cognitive interview


  police adopted the cognitive interview to ensure they get all the detail they can from witnesses which in turn reduces miscarriages of justice and ensures just prosecution
• the weapon effect


  in violent crimes, the arousal may focus the witness on more central details of the attack, such as a weapon, than more peripheral details, such as what the offender was wearing.
• Johnson and Scott


  Two conditions took place in a lab waiting room meaning ppts thought they heard a genuine discussion taking place in the lab

  1. there was an amicable discussion, about equipment failure, and a man emerged holding a pen with greasy hands.

  2. there was a hostile discussion, followed by the sound of breaking glass and a man emerged holding a paper knife with bloody hands.

  1- 49% correctly identified the man 2- 33%, results suggest that the people who were exposed to the knife had higher levels of anxiety therefore, the anxiety associated with seeing the knife reduces the accuracy of EWT
• anxiety improving recall


  during the fight or flight response adrenalin is released, this may increase witnesses alertness and improve recall as they become more aware of cues in the situation
• Yuille and Cutshall


  studied a real life shooting where the shop owner was shot dead

  13 witnesses interviewed 4-5 months after and these were compared to the original police interviews taken at the time of the shooting

  accuracy was determined by the number of details reported in each account, witnessed were also asked to rank how they felt at the time of the incident and if they had any emotional problems (sleeplessness)

  the witnesses were highly accurate in their accounts with little changes found in accuracy, ppts who reported the highest levels of stress were the most accurate
• Christiansons and Hübinette


  evidence of enhanced recall gathered from interviews of 38 real witnesses to bank robberies in Sweden

  - witnesses were either victims (obtaining high anxiety) or bystanders (lower levels of anxiety)

  - interviews conducted 4-15 months after the robberies

  - all the witnesses showed generally good memories for details about the robbery itself (<75% accurate recall) showing that the witnesses who were most anxious had the best recall of events

  - evidence that anxiety doesn't reduce the accuracy of recall
• explanations for forgetting


  interference and retrieval failure
• interference


  forgetting because one memory blocks another, causing one or both memories to be distorter or forgotten
• proactive interference


  when older memories disrupt the recall of new memories
• retroactive interference


  when newer memories disrupt the recall of older memories that are already stored
• rugby player studies


  Evidence for retroactive interference:

  Baddeley and Hitch asked rugby players to remember the names of the teams they had played that season, week by week.

  Results found that recall wasn't down to how long since the last game, but how many games they've played since.
• retrieval failure


  the inability to recall long-term memories because of insufficient cues
• encoding specificity principle


  the idea that cues have to be present at encoding and retrieval to help us recall informations
• types of cues


  context-dependent

  state-dependent

  Meaningful
• Diver study


  support for context dependent cues:

  Godden and Baddely found that different external cues at learning and recall result in retrieval failure

  - divers learnt a list of words either underwater or on land, they then had to recall the words either underwater or on land.

  The two conditions that matched had a recall 40% higher than the non-matched

  
  

  - criticised for testing recognition not recall (lowers internal validity), artificial task, extreme and unrealistic environments
• Goodwin's study


  support for state-dependent cues:

  male volunteers asked to remember a list of words either drunk or sober and then recall the list after 24hours when some were sober and others got drunk again.

  recall scores suggest that info learnt when drunk is more available to ppts if in the same state again later.
• short term memory


  information we're currently aware of or thinking about
• coding in STM


  acoustically
• Baddeley STM coding


  two groups of ppts: group A learnt acoustically similar words and group B acoustically dissimilar words and the ppts were asked immediately to recall the words immediately
• results of Baddeley STM


  ppts in group A performed the worst, recalling only 10% of the words because they confused similar sounding word
• capacity of STM


  7 +/- 2
• Jacobs capacity of STM


  a number of digits is given to participants who then have to recall them in the correct order

  the amount of digits given increased by 1 and ppts had to recall until they couldn't recall the correct order. This determines their digit span the mean digit span was 9.3 items and for letter it was 7.3
• Miller's law


  he recognised that things tend to come in 7's and believed the STM could hold 7 +/- 2
• duration of STM


  18-30 seconds