psych memory

• The tunnel theory of memory

  Argues that a witness's attention is on the weapon (weapon focus), because it is a source of danger and anxiety
• Witnesses rated how stressed they felt at the time of the incident
• Unethical
• Witnesses were very accurate and there was little change
• Study 1: Johnson and Scott

  1. Participants sat in a waiting room believing they were going to take part in a lab study

  2. Each participant heard an argument in the next room

  3. Low-anxiety condition: a man walked through the waiting room carrying a pen with grease on his hands

  4. High-anxiety condition: the heated argument was accompanied by the sound of breaking glass. A man then walked through the room holding a paper knife covered in blood

  5. Participants were later asked to pick the man from a set of 50 photographs

  6. 49% of participants in the low-anxiety condition were able to identify him. The corresponding figure for high-anxiety participants was just 33%
• Study 1: Johnson and Scott - Anxiety has a negative effect


  1976
• This is weapon focus
• Study 2: Yuille and Cutshall


  1. In a real-life crime a gun-shop owner shot a thief dead. There were 21 witnesses, 13 agreed to participate in the study

  2. Participants were interviewed 4-5 months after the incident

  3. Accounts were compared to the police interviews at the time of the shooting
• Study 2: Yuille and Cutshall - Anxiety has a positive effect


  1986
• The anxiety associated with a situation may affect recall