Anxiety

• what effects does anxiety have?

  strong emotional and physical effects
• what does anxiety create?

  physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
• what is one approach to studying anxiety and EWT?


  to look at the effect of the presence of a weapon which creates anxiety
• what does the presence of a weapon creating anxiety lead to?

  a focus on the weapon, reducing a witness' recall for other details of the event
• procedure of Johnson and Scott's study

  - ppts believed they were taking part in a lab study

  
  

  - while seated in a waiting room ppts in the low anxiety condition heard a casual conversation in the next room and then saw a man walk past them carrying a pen and with grease on his hands

  
  

  - other ppts overheard a heated argument, accompanied by the sound of breaking glass

  
  

  - a man walked out of the room, holding a knife covered in blood

  
  

  - this was the high anxiety condition
• what did ppts in Johnson and Scott's study believe?

  that they were taking part in a lab study
• while seated in a waiting room, what did ppts in the low anxiety condition hear?

  a casual conversation in the next room and then saw a man walk past them carrying a pen and with grease on his hands
• what did ppts in the high anxiety condition of Johnson and Scott's study hear?


  - other ppts overheard a heated argument, accompanied by the sound of breaking glass followed by a man walking out the room holding a blood covered knife
• findings of Johnson and Scott's study

  - the ppts later picked out the man from a set of 50 photos, 49% who had seen the man carrying the pen were able to identify him

  
  

  - the corresponding figure for the ppts who had seen the man holding the blood covered knife was 33%
• how many of those who had seen the man carrying the pen were able to identify him?

  49%
• how many of those who had seen the man holding the blood covered knife identify him?

  33%
• what is the tunnel theory of memory?

  argues that people have enhanced memory for central events, weapon focus as result of anxiety can have this effect
• what does witnessing a stressful event create?

  anxiety through physiological arousal within the body
• why my the fight or flight response improve memory for the event?

  because due to increased alertness, we become more aware of cues in the situation
• procedure of Yuille and Cutshall study

  - conducted a study of an actual shooting in a gun shop in Vancouver

  
  

  - the shop owner shot a thief dead

  
  

  - there were 21 witnesses - 13 took part in the study

  
  

  - they were interviewed 4-5 months after the incident and these interviews were compared with the original number of police interviews at the time of the shooting

  
  

  - accuracy was determined by a number of details reported in each account

  
  

  - the witnesses were also asked to rate how stressed they had felt at the time of the incident and whether they had any emotional problems since the event
• how many witnesses took part in Yuille and Cutshall's study?

  13
• when were the witnesses interviewed?

  4-5 months after the incident
• what were the interviews in Yuille and Cutshall's study compared with?

  the original number of police interviews at the time of the shooting
• what was accuracy in Yuille and Cutshall's study determined by?

  a number of details reported in each account
• what were the witnesses in Yuille and Cutshall's study asked to do?

  - the witnesses were also asked to rate how stressed they had felt at the time of the incident and whether they had any emotional problems since the event
• findings of Yuille and Cutshall's study

  - the witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after 5 months

  
  

  - some details were less accurate, such as recollection of the colour of items and age/height/weight estimates

  
  

  - those ppts who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less stressed group)
• how accurate were the witnesses of Yuille and Cutshall's study?

  - the witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after 5 months
• what was not so accurate in Yuille and Cutshall's study?

  - some details were less accurate, such as recollection of the colour of items and age/height/weight estimates
• who was the most accurate in Yuille and Cutshall's study?

  - those ppts who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less stressed group)
• what do the findings that those who were the most stressed being the most accurate in Yuille and Cutshall's study suggest?

  that anxiety does not have a detrimental effect on the accuracy of eyewitness memory in a real world context and may even enhance it
• what did Yerkes and Dodson suggest?

  the relationship between emotional arousal and performance looks like an inverted 'U
• what did Deffenbacher review?

  21 studies of EWT and noted contradictory findings on the effects of anxiety
• what did Deffenbacher use to explain his findings?

  the Yerkes-Dodson law
• what does the Yerkes-Dodson law suggest?

  - when we witness a crime or accident we become emotionally and physiologically aroused - we experience anxiety as well as physiological changes in our body (fight or flight response)

  
  

  - lower levels of anxiety/arousal produce lower levels of recall accuracy, and then memory becomes more accurate as the level of anxiety/arousal increases

  
  

  - however, there is an optimal level of anxiety, which is the point of maximum accuracy

  
  

  - if a person experiences any more arousal, then their recall suffers a drastic decline
• limitation - Johnson and Scott's study may not have tested anxiety

  - the reason ppts focused on the weapon may be because they were surprised at what they saw rather than scared

  
  

  - Pickel conducted an experiment using scissors, a handgun, a wallet or raw chicken as the hand held items in a hairdressing salon video

  
  

  - eyewitness accuracy was significantly poorer in the high unusualness conditions (chicken and handgun)

  
  

  this suggests that the weapon focus effect is due to the unusualness rather than anxiety/threat and therefore tells us nothing specifically about the effects of anxiety on EWT
• Strength - there is evidence supporting the view that anxiety has a negative effect on the accuracy of recall

  - Valentine and Mesout supports the research on weapon focus, finding negative effects on recall

  
  

  - the researchers used an objective measure (heart rate) to divide ppts into high and low anxiety groups

  
  

  - in this study, anxiety clearly disrupted the ppts' ability to recall details about the actor in the London Dungeon's Labyrinth

  
  

  this suggests that a high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event
• Strength - evidence showing anxiety can have positive effects on the accuracy of recall

  - Christianson and Hubinette interviewed 58 witnesses to bank robberies in Sweden

  
  

  - some of the witnesses were directly involved and some were indirectly involved

  
  

  - the researcher assumed that those directly involved would experience the most anxiety

  
  

  - it was found that recall was more than 75% accurate across all witnesses, the direct victims were even more accurate

  
  

  these findings from actual crimes conforms that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enhance it

  
  

  however, there is potential for a lack of control over confounding variables as researchers interviewed their ppts several months after the events so had no control over what happened to the ppts in the intervening time