Eyewitness Memory and Interviewing Witnesses - Lecture 1 Flashcards
What is eyewitness testimony?
It is evidence given by a witness to a crime, typically in the form of a verbal account or person identification.
What are they asked to recall?
Episodic memories.
What are episodic memories?
These are memories for personally experienced events. Tend to retain details of time and situation in which these memories were acquired of when, where and what happened.
Why is research on Human memory important for the law?
Because memory needs to be 100% accurate and eyewitness accounts are considered to be compelling by jurors. Also, eyewitness misidentification is the leading cause of wrongful conviction.
What percentage of cases does eyewitness misidentification occur in?
12%. There have been 325 post-conviction DNA exoneration cases in US of which 20 served time on death-row and 13.6 years was the average time served.
Why do eyewitnesses make errors?
Memory processing occurs in three stages and an error can occur at any stage.
What is the first stage of memory processing?
Stage 1 = Acquisition/Encoding which is the information that the person receives.
What is stage two of memory processing?
Stage 2 = Storage/retention which is the information that the person stores in their memory.
What is stage 3 of memory processing?
Stage 3 = Retrieval which is the information that the person retrieves later.
Why is stage 1 so important?
Because it forms a basis for what is stored in memory and eventually retrieved when giving a testimony.
Which 5 factors affect the quality of the information encoded into memory?
1) Exposure duration
2) Crime seriousness
3) Violence
4) Weapon presence
5) Perpetrator characteristics eg. disguises
What is top-down, bottom-up processing?
Bottom-up = data driven and begins with an image that falls onto retina. Information is transmitted up to higher levels of visual systems until object is perceived. It builds from individual stimulus features to unified perception.
Top-down = Sensory information that is interpreted in light of prior knowledge, concepts and expectations.
What is perceptual set? And who invented the concept?
It is the idea that cues can ‘set’ the individual to interpret impoverished info in a certain way.
It was invented by Bugelski and Alampay (1961)
What are past experience-schemas?
They are a mental framework or body of knowledge that helps us make sense of familiar situations.
What do past experience schemas do?
They guide our expectations and provide a framework within which new information is processed and organised.
What are common schemas called?
‘Scripts’ - people can have scripts for events they have never witnessed before eg. what a robbery would involve.
Who invented the concept of schemas?
Bransford and Johnson in 1972. (the washing clothes scenario)
What is the schema theory?
It suggests that we remember items better if they fit in with our schema and previous experience.
NOTE: expectations and prior knowledge can lead to errors.