Factors affecting EWT (anxiety)

• Anxiety def


  -State of emotions & physical arousal.

  -Includes thoughts of worry and tension.

  -Physical changes: higher bpm & sweatiness

  -can affect accuracy if detail of EWT
• Who did research on the negative effect on recall

  Johnson and Scott
• What method did Johnson & scott use

  -Ppt believes they were taking part in lab experiment but while waiting heard casual convo next door and saw man walk past carrying a pen with grease on hands. Then heard heated argument then sound of break glass then man walked past the room holding a knife with blood on his hands
• Result of Johnson and scott

  - 49% ppt picked out man holding pen (out of 50 photo)

  - but only 33% identified knife man
• Conclusion of Johnson and scott

  Knife exposure increases levels of anxiety and weapon focus effect occurs (focus on knife rather than face(
• Who found that anxiety has a positive effect of recall

  Yuille and Cutshall
• What method did Yuille and Cutshall use

  -Actual shooting in gun shop in Vancouver, Canada (shop owner shit thief dead)

  -21 witnesses (13 took part in study)

  -accuracy was determined by no. of details reported in each account

  -witnesses were asked to rate how stresses they felt at the time (on 7 point scale) if they experienced emotional issues since the event (eg imsomnia)
• What were the findings of Yuille and Cutshall

  Witnesses were v accurate & little change in recall & accuracy after 5 months (but some a little less accurate eg estimates of height)

  -Those who reported more stress were more accurate (88% vs 75% less stressed)

  -Suggests anxiety doesn't have detrimental effect on accuracy of EWT in real world application (may even enhance it)
• Who developed inverted U theory

  Yerkes-Dodson
• Yerkes-Dodson Law def


  -Low level of anxiety produce bad recall, but memory becokes mroe accurate as anxiety increases

  -Optimal level of anxiety

  -If witness experiences too much anxiety, recall is reduced
• Evaluation... ...
• Strengths of anxiety as a factor of EWT

  +Evidence support for negative effects

  +Support for positive effects

  ​
• What supporting evidence is there for :)

  +Tim Valentine & Jan Mesout used heart rate to divide ppt into high & low anxiety groups. Anxiety clearly interrupted ppt ability to recall ab actor in London Dungeons Labyrinth. So high level of anxiety has bad effect on immediate recall of stressful events
• What is support for positive effect :)

  +Christianson & Hubriette interviewed 58 witnesses to recall bank robberies in Sweden. Some were directly involved (bank workers) and others bystanders. Researchers assumed directly involved had more anxiety. Recall was 75%+ accurate across all witnesses but direct victims (who were more anxious) were msot accurate
• Weaknesses of anxiety as a factor of EWT

  -Usualness not anxiety

  -Problems w/inverted U theory
• How is Usualness not anxiety a weakness

  -May not have tested anxiety (surprised not scared)

  -Pickel used scissors, handgun, wallet or raw chicken. EWT was worse in unusual conditions (scissors or raw chicken)
• What problems are there iwrh inverted-U theory

  -Inverted U theory is a reason explanation of contradictory findings linking anxiety w/ better/worse EW recall

  -BUT ignores fact that anxiety has many aspects (cognitive, behavioural, emotional & physical)

  -Only focuses on physical arousal & assumes that is only aspect (but cognitive reaction may be important)