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
Describe the booklet mailed to the participants in Loftus’ study, and the details of the false memory that was constructed
- 5-page booklet
- cover letter with instruction and scheduled interviews
- four short stories: three true events described by relative that occured when the subject was aged 4-6
- false event: lost for an extended period of time in a mall or large department store at about 5 years old, crying, found and aided by an elderly woman, then reunited with the family
- to make the memory believable, details provided by the relative included:
- where the family shopped at that age
- which members of the family usually went on shopping trips
- what kinds of stores attracted the subject’s interest
Describe the results found in Loftus’ study on the formation of false memories
- 49/72 of true events remembered across the booklet and both interviews
- 7/24 remembered false event; one subject recalled the event at first then decided she did not remembered so 6/24 in the end
- More words used to describe true memories (mean 138) than false memories (mean 49.9)
- Ratings for 5 participants who falsely remembered being lost:
- Clarity: mean 6.3 and 6.3 for true events, 2.8 and 3.6 for false event
- Confidence: 2.7 then 2.2 for true events, 1.8 then 1.4 for false events
- 19/24 correctly guessed false event
Evaluate Loftus’ study on the formation of false memories
- Generalisation: no, educated sample (known to University students), gender imablance
- Reliability: high, supported by previous studies, many controls
- Validity: low, semi-structured interviews with suggestions so data is perhaps distorted by the interviewers, Likert scale (subjects avoid extreme values and may be drawn to pick the middle value), mean values are skewed
- Ecological validity: low, unusual situation for a relative to make up a false event
- Ethics: high, debriefing; low, deception, no informed consent, altering memory
- Usefulness: high, eyewitness testimonies and the danger of leading questions
Define
sensation and perception
Sensation is the process of bringing information from the external world into the internal body and brain.
Perception is the process of selecting, organising and interpreting the raw information that has been taken to the brain by your senses (i.e. touch, taste, sight, sound and smell).
Held and Hein investigated perception, which is involved in visually guied behaviour.
What was the background and aim of Held & Hein’s study (kitten carousel)?
- Hebb (1949): the effects of exposure to the environment of the development of spatial perception and coordination
- Walk & Gibson (1961): visual cliff
- Aim: To investigate if self-produced movement with its concurrent visual feedback is essential for the development of visually-guided behaviour
Describe Held and Hein’s method and sample
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Lab experiment with controlled observation
- IV: active/passive kitten, exposure to light
- DV: results for tests
- controls: movements of kittens, visual stimuli of kittens
- 20 kittens (10 pairs)
- One ‘active’ A and one ‘passive’ P kitten in each pair
- Kept in lightless cages with littermates and mother to reduce anxiety
- Group X (8 pairs): reared in darkness from birth until A attained the minimal size and coordiational capacity required (8-10 weeks), then began experiment
- Group Y (2 pairs): exposed to the patterned interior of a laboratory while restrained from 2-10 weeks of age for 3hrs daily, then began experiment
Describe the main tests of visually guided behaviour in Held & Hein’s study
- Visually-guided paw placement: The kitten was held by an experimenter. Its head and forelegs hung freely. It was carried down to the edge of a table. A kitten with normal visual experience would extend its paws in anticipation of contact with the table.
- Avoidance of a visual cliff: The kitten was placed onto a transparent cliff-shaped block. It was placed onto the centre. One side looked ‘shallow’ and the other looked ‘deep’. A kitten with normal visual experience completely avoids the deep-looking side because they have a perception of different depths.
- Blink to an approaching object: The kitten was held in a standing position. The experimenter quickly brought his hand towards the kitten’s face, stopping just in front of it. A kitten with normal visual experience would blink in response.
Describe the additional tests done by Held & Hein to check the peripheral receptors and response mechanisms of the kittens
- Visual pursuit of a moving object: The experimenter moved their hand slowly in front of the kitten. The kitten’s eye movements were recorded. A kitten with normal visual experience would follow the hand with its eyes.
- Pupillary reflex to light: A torch beam was moved across the kitten’s eyes. Any change in pupil size was noted. The pupil of a kitten with normal visual experience would shrink in response to the light.
- Tactual placing response: The kitten was held with its forelegs hanging freely. Its front paws were placed against the vertical surface of a table. A kitten with normal visual experience would respond by moving its paws into a horizontal position on the table surface.
Describe the procedure for Held and Hein
- Apparatus allowed A to move with the motions mechanically transferred to P (use of ball bearings and aluminium reduced friction and inertia)
- P restrained in a gondola to prevent locomotion, head was free to move
- Group X:
- exposed to apparatus for 3hrs daily, with 6 repetitions of paw-placement test after each exposure
- on the 1st day that one kitten in each pair passed this test, both were tested on the visual cliff
- retested the following day, then P left in a continuously illuminated room for 48hrs, then retested
- Group Y:
- on the first day A displayed visual paw placing, it was tested on the visual cliff and retested the next day
- passive exposure continued 3hrs daily for total 126hrs, then P tested
