anxiety

• weapon focus 


  tendency for witnesses who observe and armed criminal, to direct their attention towards the weapon- so fail to encode perpetrators physical appearance
• weapon focus/ tunnel vision (simple)


  eyes drawn to weapons, unexpected objects
• loftus + burns (1982)


  video, violent crime of boy being shot in face

  impaired recall for event running up to incident

  anxiety has a negative effect on memory recall, as witnesses would repress the memory
• christianson + hubinette (1993)


  58 victims of bank robbery, real life

  those who had been threatened more, were more accurate in recall, compared to bystanders

  continued to be true 15months later

  suggest anxiety has a positive effect, as the heightened reactions caused the ppt to pay more attention
• What was the main focus of Johnson and Scott's (1976) study?

  The effect of a weapon which causes anxiety
• How does the presence of a weapon affect a witness's recall of an event?

  It reduces a witness's recall for other details of the event
• What were the conditions of the experiment conducted by Johnson and Scott?

  • Condition 1: Low anxiety (casual conversation, man with a pen and greasy hands)
  • Condition 2: High anxiety (heated argument, man with a knife and bloody hands, broken glass sound)
• What percentage of participants accurately identified the man in the low anxiety condition?

  49%
• What percentage of participants accurately identified the man in the high anxiety condition?

  33%
• What is the tunnel theory of memory as proposed by Johnson and Scott?

  • Enhanced memory for central events
  • Weapon focus as a result of anxiety can have this effect
• What is the relationship between anxiety and memory recall according to Johnson and Scott's findings?

  Higher anxiety leads to reduced recall of details
• johnson + scott (1976)


  participants believed they were going to participate in a lab study, yet the experiment started in the waiting room
• johnson + scott (1976) evaluation 


  • lab study- highly controlled so can be replicated
  • lab study- artificial, lacks ecological validity as it causes demand characteristics
• yerkes-dodson law

  
• yerkes-dodson law


  performance improves as arousal increases up to some optimum point and then declines with further increases
• evaluation of johnson + scott (1976)


  • pickel (1998) - suggested that johnson + scott, weapon focus only tested surprise rather than anxiety
• pickel (1998) can only be used for evaluation not outline 


  repeated johnson + scott (1976) with different conditions
• pickel (1998)


  a = weapon focus is due to surprise not anxiety

  p= conditions: scissors, handgun, wallet or raw chicken as handheld items in a hairdressing salon video

  f = eye witness accuracy was poorer in high unsusualness conditions- handgun and raw chicken

  c = suggest that anxiety is not the cause of poorer recall, but instead surprise

  chicken would cause surprise not anxiety, yet took ppt focus
• field study research


  • less control over extraneous variables - eyewitnesses could talk to eachother and influence the experiment
• ethics 


  lab is controlled but hard to create genuine emotion

  field lacks control , but has genuine emotion

  unethical to create a real shooting
• hard to carry out research that is valid but creating anxiety