Memory 2

Memory 2

1. Eye witness testimony: Misleading info

   • Why leading Qs affect EWT: RESPONSE BIAS EXPLANATION- Wording of a question has no enduring effect on an eyewitness testimony of an event but influences answer given
     • SUBSTITUTION EXPLANATION: wording of a Q does affect eye witness memory; it interferes with its original memory, distorting its accuracy
     • LOFTUS AND PALMER EXP procedure: 45 student pps watched film clips of car accidents and then answered Qs about speed to make it real. The critical Q measure was 'How fast were the cars going when they hit each other?' there were 5 groups of pps and were all given a diff verb in the Q : HIT, CONTACTED, BUMPED, COLLIDED and SMASHED Findings: the verb 'contacted' had a mean estimate of 31.8 mph and the verb 'smashed' had a mean est of 40.5 mph. the leading q biased EW recall of an event as the verb smashed got a higher mph est than 'contacted'
       • GABBERT ET AL procedure:paired pps watched a vid of the same crime at diff angles. both pps discussed what they had seen before individually tested on recall findings: 71% remebered aspects that didn't happen but they had picked up from the other pp. in the cont group: no discussion and no errors
     • Post event discussion (PED) memory contamination is when co-witnesses discuss a crime, mix info from others with their memory. memory conformity is when witnesses discuss and go along with each other to win social approval. there all unsure so they go with others cos they believe they are right
       • E: research into misleading info had real life application. the research had important practical uses for police officers because the inaccuracy of EWT is very serious. eg Loftus claimed that leading Qs can have such a distorting influence on memory that police need to watch how they phrase their Qs when interviewing ppl. research into EWT is where researchers can benefit the publics life and make a difference eg in the legal system
         • E: L-individual diffs in accuracy of EWT eg Anastasi and rhodes found that older ppl were far less accurate than youth when giving EWT however, they also found that all age groups were more accurate when identifying ppl of their own age group. research studies often use younger ppl as the target to identify . so age groups may seem less accurate but not always the case
       • E: L-loftus and palmers study used artificial materials as pps watching a clip of an accident is very diff from witnessing in real life Eg less stressful. Yuille and cutshall found that witnesses of an armed robbery still had accurate recall after 4 months. this shows that using artificial tasks tells us little about how leading Qa affect EWT in real crimes

2. EWT: Anxiety

   • ANXIETY HAS A NEGATIVE EFFECT ON RECALL Johnson and scott pps are sat in a waiting room thinking there waiting for a lab study to start. each pp heard an argument in the next room in the low anxiety condition: a man walked through with greasy hands and a pen. cond 2 high anxiety: loud argument, glass breaking and man walks through with paper knife covered in blood. pps were later asked to identify man from pics.
     • findings: in cond 1: 49% could identify right and in cond2: 33% identified. this is because the TUNNEL THEORY OF MEMORY argues that a witnesses attention is on weapon because its a source of danger/anxiety
       • E: Limitation: johnsons and scotts study may test surprise not anxiety pps may have focused on weapons because they're surprised not scared. For instance Pickel used scissors, handgun wallet and raw chicken as handheld items in a hair salon.EWT was poor for high unusualness eg raw chicken and gun so the 'weapon focus' effect is due to the unusualness rather than anxiety and therefore tells us nothing specifically on effects of EWT on anxiety
         • E: Lim: field studies lack a control of variables as real life EW were interviewed after the event.many things happen to them in the meantime that researchers cannot control. eg memory contamination/conformity or reading the media reports. these extraneous variables may be responsible for the (in)accuracy of recall not anxiety. it's difficult to isolate the variables.
           • E: Lim; there are ethical issues with this research area as creating anxiety in may subject pps to psychological harm so RL studies are benficial as the researchers interviewed EW that already witnessed an event-no need to create it. ethical issue don't challenge the findings (e.g johnson and scott) but do raise Qs about conducting this research
             • E: the inverted U explanation is too simplistic/limited. anxiety is difficult to measure because it has many elements (cognitive, behavioural and physical. The inverted U explanation assumes that one one of these is linked to poor performance- physiological arousal. this explanation fails to account for other factors eg the emotional effects of witnessing a crime (terror/fear etc) on the accuracy of memory
     • ANXIETY HAS A POSITIVE EFFECT ON EWT Yuille and cutshall looked as a real life armed robbery where the gun shop owner shot the thief dead. there were 21 witnesses and 13 agreed to participate. witnesses rated how stressed they felt at the time. findings: witnesses were very accurate and little change after 5 months. some details less accurate eg colour of items/height/age & pps who reported the highest levels of stress were more accurate than those less stressed (885 compared to 75%)
     • INVERTED U THEORY yerkes and doson argue that the relationship between performance and stress is curvilinear not linear. daffen bacher found that lower levels of anxiety did produce lower levels of recall accuracy. recall accuracy increases with anxiety to a certain point -optimal point

3. Cognitive Interview

   • FISHER AND GEISALMAN claim that the EWT could be improved if the police use techniques based on psychological insights into how memory works, they called it the CI to indicate its foundation in cognitive psychology. understanding is established with interviewee
     • 1) REPORT EVERYTHING: witnesses encouraged to include every detail of an event-however irrelevent it may seem. trivial details could be important and may trigger other memeories
       • 3) REVERSE THE ORDER events are recalled from a diff chronological order (eg from end to beginning) this prevents ppl using their expectations of what should have happened rather than what did. also prevents dishonesty as its harder to lie this way
         • ENHANCES CI: fisher et al developed additional elements of CI. this included focus on the social dynamics of the interaction (eg. knowing when to establish eye contact) the CI also included ideas such as reducing EW anxiety, minimising distractions and getting the witness to speak slowly plus open Qs
           • E: some elements of CI are useful. 2 researchers found that each induvidual element of CI was equally valuable. However, they also found that a combo of 'report everything and 'reinstate C' produced better recall than any of the other techniques individually. so at least these 2 elements should be used to improve police interviewing of eyewitnesses even if full Ci isn't used
             • E: strength is the support for effectiveness of enhanced CI. For instance a meta analysis by kohnken et al combined data from 50 studies where the enhanced CI consistently provided more correct info than the standard police interview. studies like this indicate that there are real life practical benefits to the police using the original CI
               • E: limitation is that research may be unreliable due to variations of CI. studies of effectiveness of CI use slightly diff techniques. diff researchers may use variations of CI or E-CI nd police evolve their own methods. this means that it is difficult to draw conc on Ci in general
             • E: a limitation is that the CI is time consuming and the police are even reluctant to use it because its takes more time to establish rapport with EW and to allow them to relax. 2 researchers point out that CI also requires special training and many forces cannot provide more than a few hours. this means its unlikely that the 'proper' version of CI is actually used
     • 2) REINSTATE THE CONTEXT the witnesses return to the original crime scene in their mind and re-imagine the environment (eg the weather/what they see) and their emotions (how they felt). this is based on 'Context Dependant Forgetting' - environmental cues trigger recall
       • 4) CHANGE PERSPECTIVE witnesses recall the incident from other ppl's perspective. how would it have appeared to anther witness or to perp? this prevents influence of expectations and schema's on recall.

4. Coding/capacity & duration of memory

   • Baddeley: coding in STM and LTM exp -- procedure: 4 groups to learn one liste each, ACOUSTICALLY SIMILAR words (eg.cat/dog) or DISSIMILAR (eg.pit/few). SEMANTICALLY SIMILAR (eg.large,big) or DISIMILIAR (eg.good/hot) F: immeadiate recall worse with SEMANTICALLY DISSIMILIAR so STM is acoustic. = recall after 20 mins worse with SEMANTICALLY DISSIMILIAR words. LTM is semantic
     • E: limitation is that it didnt use meaningful material. The words used in the study had no personal meaning to pps. when processing meaningful info, ppl may use semantic coding even for STM tasks. This means the results of this study have limited applicationand we should be cautious about generalising the finding to other mmeory tasks
       • E: limiation is that this study was conducted a long time ago. early research often lacked adequete control of extraneous variables. eg some pps may have been distraacted whilst being tested so didnt preform as well as they should. this would mean the results may not be valid due to confounding variables that weren't controlled. BYT these results have been confirmed in other research so validity is supported.
       • E: A limitation is that Miller's research may have overestimated the capacity of STM. cowan et al reviewed other research and concluded that the capacity of STM is only about 4 chunks. This suggests that the lower end of Miller's estimate (5 chunks) is more appropriate than 7
     • Jacobs (1887) Capacity of STM P: Digit span: researcher read 4 digits and increases until pp cannot recall order correctly. F: On ave. pps could repeat back 9.3 numbers and 7.3 letters in the correct order.
       • Peterson and peterson studey - duration of STM: 24 pps were given a consonant syllable (eg. YCG) to remember and a 3 digit number to count back from <--prevented maintenance rehearsal at interval secs of 3,6,9,12,15 and 18. 80% of students who had a 3 sec interval recalled the consonant syllables accurately. at 18 seconds: 3% recalled the consonant S accurately. This suggests that duration of STM lasts 18-30 seconds
         • E: A limitation of this study is that it uses an artificial stimulus as trying to remember consonant syllables does not reflect most real life memory activities where what we try to remember is meaningful. IT could be argues that it lacked external validity. On the other hand, we do sometimes try to remember fairly meaningless things such as phone numbers. so study isn't completely irrelevant
           • E: a strength is that this study has high external validity as it used real meaningful memories. Sheppard recreated this study with meaningless pics and found recall rate was much lower. The downside of Rl studies is that confounding variables cannot be controlled. e.g bahricks pps may have have looked at the year book often since they graduated and therefore rehearsed it into their LTM
         • Bahrick et al - duration of LTM study: --P: pps were 392 American males aged: 17-74 they had a RECOGNITION TEST where they had to try to remember the names of pupils from their yearbook. and the second was a free recal test which they recalled the names of of their graduating class. F: pps tested 48 years after the graduation were 70% accurate in photo recognition. free recall was less accurate.
     • Miller capacity of STM study --P: Miller made observations of everyday practice and noticed that things come in 7's. e.g. 7 days of the week, 7 deadly sins etc--F&Conc: he concluded that the span of the STM is about 7+/-2 items but can be improved by chunking (grouping sts of digits/letters into meaningful units

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