Cognitive Psychology Flashcards
What was the background and aim of Vrij & Mann’s study?
- No real background - previous experiments were low in ecological validity as lies were artificial
- Aim: to conduct a study examining the behaviours of authentic high-stake liars
- Expected decrease in nonfunctional movements and behaviours consistent with cognitive load and/or behavioural control, presence of nervous behaviours uncertain
What method did Vrij & Mann use?
Describe the sample
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Naturalistic observation: subjects did not know they would be analysed
- IV: veracity, but not manipulated by experimenters
- DV: behaviours
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Self selecting sample with repeated measures design: the suspects were known to have made both truth and lie statements
- 13 males, 3 females
- 4 juveniles (three 13yrs, one 15yrs)
- 12 adults under 65yrs
- 15 Caucasian, 1 Asian (1st language Punjabi, fluent in English)
- Crimes: 9 theft, 2 arson, 1 attempted rape, 4 murder
- at least 10 had been previously interviewed for other crimes
Describe the procedure for Virj & Mann’s study (authentic high-stake liars)
- Video tapes obtained from Kent County Constabulary with truth/lie supported by other evidence
- 65 clips chosen with 27 truths, 38 lies - truths and lies comparable in nature
- At least one truth & one lie for each subject - min. 2, max. 8 clips
- 5.2-145.7s per clip, 41.4-368.4s per subject
- Clips joined to make an hour long video
- Two observers (not told purpose of activity) coded the footage for intances of behaviour in 8 categories (quantitative data)
- Observer 2 randomly coded 36 clips, inter-rater reliability checked (e.g. r = .86 for gaze aversion and .99 for blinking)
List and describe the 8 behaviour categories coded by the observers in Vrij & Mann’s study
- Gaze aversion: seconds looking away from interviewer
- Blinking: frequency
- Head movements: frequency of head nods, shakes, tilts, etc.
- Self-manipulations: e.g. scratching
- Illustrators: movements to modify/supplement verbal information
- Hand/finger movements: without moving arms
- Speech disturbances:‘ah’, ‘mmm’, sentence incompletion, stutters, sentence change
- Pauses: approx. 0.5s or more betwee words
List the controls in Vrij & Mann’s study
- The researchers did not code the clips due to possible bias
- Subjects’ truths and lies confirmed by police
- Truths comparable in nature to lies
- Observers were naïve - not told the purpose of the study or whether a statement was true/false
Describe the results of Vrij & Mann’s study
- Lies:
- decrease in blinking (81%) (mean 18.50 compared to 23.56)
- increase in pauses (81%) (mean 5.31 compared to 3.73)
- decrease in hand and arm movements (69% decrease, 31% increase)
- Individual differences occured:
- 50% increase, 50% decrease for head movements and speech disturbances
- 56% increase, 44% decrease for gaze aversion
What can be concluded from Vrij and Mann’s study on high-stake liars?
- lying was accompanied by a decrease in blinking and an increase in pauses (possible indicators of cognitive load)
- decrease in blinking indicates cognitive affects suspects’ behaviour more than nervousness
- individual differences challenge popular belief that liars have one set of behaviours: blinking rapidly, fidgeting and avoiding eye contact
Evaluate Vrij & Mann’s study
- Generalisation: no, all were criminals (10 had been interviewed several times previously for other offences), 16 is a small sample
- Reliability: low, no real background, different interviewers (sometimes more than one), sometimes other people (attorney, parents) were present, 10 subjects had previously been interviewed
- Validity: high, coders were naïve so no bias, participants did not know they were studied; however, behaviour categories may not have been comprehensive enough
- Ecological validity: high, real-life situation
- Ethics: low, no consent, criminal records are meant to be confidential
- Usefulness: high, helps police BUT not applicable in other situations
Define
retroactive and proactive interference
Retroactive interference: occurs when current information works backwards to interfere with earlier information
Proactive interference: occurs when current information is lost because it is mixed up with previously learned, similar information
What was the background and aim of Loftus and Pickrell’s study on the formation of false memories?
- Previous experiements by Loftus
- car crash (leading questions; broken glass)
- Loftus & Coan - 14 year old Chris rated clarity of false memory as 8
- Aim: to investigate whether it is possible to implant an entire false memory for an event that never happened, i.e. being lost in a shopping mall
Describe Loftus’ implantation of a false memory in 14-year-old Chris
- Three true events involving mother and brother Jim
- Jim helped to construct false memory: lost in University City shopping mall, Spokane, Washington at age 5; rescued whilst crying heavily by an old man
- Chris wrote about memories every day for 5 days, with more details about getting lost (old man was ‘really cool’, scolded by mother)
- Reinterviewed a few weeks later; true memories rated 1, 10, 5 for clarity; false memory rated 8
- Thought one of the true memories was false
Describe the paradigm outlined by Loftus for conducting research into altering eyewitness memories about an event
- Participants witness a complex event e.g. a car accident or crime
- Half of participants receive misinformation whilst the other half do not
- All participants attempt to recall the event
Describe Loftus’ method
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Experiment with self-report and semi-structured interviews
- repeated measures design
- could be described as lab (interview at University of Washington) or field (phone interviews, booklet completed at home)
- IV: three stages of booklet completion, first interview and second interview
- DVs: %participants recalling true & false events; ratings of clarity (1-10 Likert scale) and confidence (1-5 Likert scale)
- Both quantitative and qualitative data collected
Describe Loftus’ sample
- Opportunity sample
- 3 males, 21 females aged 18-53 recruited by University of Washington students
- Each student provided a pair - usually parent/child or siblings - the relative had to be knowlegeable about the childhood experiences of the subject
- Possibly multiple ethnicities: mentioned Vietnamese-American
Describe Loftus’ procedure
- Interviews conducted with relatives to obtain 3 true events and information for constructing a false event (verifying the ‘lost in mall’ story was completely false)
- Subjects told the study was on childhood memories and asked to complete a 5-page booklet that had been mailed to them about their memories and how much they remembered of them
- 1st interview 1-2 weeks after receipt of the booklet, 2nd interview 1-2 weeks after that (two female interviewers) (at the Uni or by phone)
- Asked to recall events, rated clarity (1-10) and confidence that given time they would be able to remember more (1-5) (Likert scale)
- After 1st interview, participants were thanked for their time and encouraged to think about the four events; asked to remember more details for the next interview, but to not discuss the events with anyone else.
- Participants debriefed after 2nd interviewed and apologised to for the deception