Human Memory
Lesson 16
Human Memory EWT Anxiety & EWT Produced by
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Key Terms Eyewitness Testimony (EWT) • EWT can be defined as the evidence given in court or in a police investigation by someone who has witnessed a crime or an accident.
Key Study – Loftus & Burns (1982) • Loftus and her colleagues showed participants a particularly violent version of a crime in which a boy was shot in the face. • These participants had significantly impaired recall for events running up to the violent incident. • Participants were asked to sit outside a laboratory where they thought they were hearing genuine exchanges between people inside the laboratory. • In one condition, they heard an amicable discussion about an equipment failure. A man with greasy hands then came out of the laboratory holding a pen.
• In the other condition, participants outside the laboratory heard a hostile discussion, followed by the sound of breaking glass and overturned furniture. • A man then emerged from the laboratory holding a knife covered in blood. • Participants were then given 50 photos and asked to identify the man who had come out of the laboratory. • People who witnessed the peaceful scene were more accurate in recognising the man then people who had witnessed the violent scene.
• Loftus believed that anxiety elicited by the weapon (i.e. blood stained knife) narrowed the focus of attention for the witness and took attention away from the face of the man. • However, such laboratory studies might not reflect what happens in real life events. Christianson and Hubinette (1993) reported that in real life incidents involving high levels of stress, memory can be accurate, detailed and long lasting. • They carried out a survey among 110 people, who had witnessed between them 22 genuine bank robberies.
• Some of these people had been bystanders in the bank at the time of the hold-ups while others had been directly threatened by the robbers. • The victims, i.e. the people who had been subjected to the greatest anxiety, showed more detailed and accurate recall than the onlookers.
Examiners Tip on Methodology • This study shows the importance of collecting data from real, naturally occurring events when possible. • Laboratory simulations cannot, for ethical reasons , reproduce the levels of stress generated by real events and are unlikely to have the same impact as real events.