Lecture 10 Flashcards
What is eyewitness testimony? Are they accurate? What are the risks of them being wrong? (3 things)
- Testimony (e.g., in court) by an witness to a crime (bystander or victim)
- One of the most compelling types of evidence in legal cases (one of the most compelling peices of
evidence in legal cases) - However, some aspects of eyewitness testimony can be inaccurate
– Can lead to mistaken identity
– Has led to hundreds of wrongful convictions
– Implicated in ~70% of cases that were exonerated with DNA evidence
T]he spectre of erroneous convictions based on honest and convincing, but mistaken, eyewitness identification haunts the criminal law.”
(R. v. Quercia, (1990), 60 C.C.C. (3d) 380 (Ont. C.A.) at 389.)
What is the innocence project?
WATCH RECORDING
How can memory theory help us with understanding eyewitness testimonies?
Why do we sometimes make errors as eyewitnesses What kinds of errors can we make?
Eye whitnessess are not always accurate
- why do we sometimes make errors as an eye whitness
- memories are constructive, they are a cominibation of what actually happened plus our knowledge and expirences
Why do we sometimes make errors as eyewitnesses?
Memory is constructive
Memory = (what actually happens) + (person’s knowledge, experiences, and
expectations)
Our memory is not not a tape recorder we play back
Our memories change: reproductions contain omissions (leaving things out) or commissions (adding new content)
(we can leave things out that we have forgotten)
What are the pros and cons of constructive memory?
Pros
○Allows us to “fill in the
blanks”
○ Cognition is creative
○ Understand language
○ Solve problems
○ Make decisions
- you can make traumatic memories less trauamatic over time
- you can use your past knowledge to reconstruct the future
- we can use our own memory construtiv system to recreate
Cons:
Memory errors
■ False beliefs about others
■ Susceptibility to misinformation
What is a schema? Example?
Schema: knowledge about some aspect of the environment
– You know what a post office, ball game, or classroom should look like
schema is knowledge about some aspect of the environement
- we can all think about what a classroom is like
What is a script?
Script: conception of a sequence of actions that usually occurs during a particular experience
– Going to a restaurant; playing baseball (unfolding of a sequence)
Do schemas and scripts influence memory? How?
Schemas and scripts influence memory
– Our memory can include information not actually experienced but inferred because it is
expected and consistent with a schema or script
– Office waiting room: books are not present but often mentioned by participants in a memory task
both influence memory
- some research looking at this has shown if you show people an image of a office room they will fasley beleive books were present, because they expect them to be there
What is a type 1 memory error? What causes them?
Source monitoring error:
misidentifying source of a given memory
Happens to professors often
– Did I mention this in this section or the other one?
(confusing similar expirences)
cause: Errors due to suggestion
when a whitnness is being asked questions about a crime
their memory can be distorted
Examples of Suggestive questioning
– Confirming feedback
– Can be severe/unethical and lead to confessions for crimes one did not commit
– In some cases, police presented those accused with false evidence
– Can happen in therapeutic contexts as well
can lead to confessions of crime one did not commit
What is source memory?
Source memory: determining origins of our memories (mix up the source of information)
What was the becoming famous overnight study? What were the methods, results, and explanation?
Encoding:
Read non-famous names
Immediate Test Group:
Read non-famous names from encoding, new non-famous names, and new famous names.
Asked: which are famous?
Result: most non-famous names correctly labelled as non-famous (not that interesting)
Delayed Test Group (24 h):
Read non-famous names from encoding, new non-famous names, and new famous names.
Asked: which are famous?
Result: some non-famous names incorrectly labelled as famous
(Seen the names before in some capacity so they assume
that they are famous
- they misinterpreted the source of familiarity)
Explanation: some non-famous names were familiar, and the participants
Encoding: encoding AND new non- encoding AND new non-
misattributed the source of the familiarity. Failed to identify the source as the list Read non-famous famous names and new famous names and new
that had been read the previous day.
names famous names. f
What is a type 2 error?
Errors due to attention
Specific stimuli can narrow attention
– “Weapon focus”
– This leads to better memory for the “central” elements at the expense of everything else
– Would be very difficult to recall what was in the periphery if we did not attend to it
– In extreme form: crime blindness
Video
- show ppl a complex event
- tell them to watch for theft
- ppl who are givenmething different to do barely noticed the theft at all
- even when we are not paying attention to the salinet thing, we still
fill in gaps after if we are asked about it. This can be problamatic
for eye whitness testing
WATCH LECTURE RECORDING
What is the misinformation effect?
The misinformation effect: misleading information presented after someone witnesses an event can alter how that person later remembers the event (suggestion)
What was the study on misinformation effect?
Group 1: How fast were the cars going when they hit each other?
Group 2: How fast were the cars going when they smashed into each other?
One of the most famous studies looking at this
- devided the Ss in two groups and ask how fast where the cars going
when they hit OR smashed into the other car
^- this one word was the only difference
- the smashed group reported that the cars were going faster
- the smashed group was more likley to misremember broken glass
“smash” group much more likely to report a faster speed and the presence of broken glass
Who is prone to the misinformation effect?
- People of all ages are prone to the misinformation effect but some data suggests it is stronger in children and older adults.
What is the video we watched on implanting false memories? Wade and coworkers (2002)
Wade and coworkers (2002); photoshopped participant in a photo
If participants are given a few true memories and one false one, they will tend to believe the false one was true, particularly after repeated discussion.
Involves participants first picturing the event in their mind, followed by questioning.
What is the video we watched on implanting false memories? (Julia Shaw (2015))
Picture yourself at the age of 14 in Kelowna in the Fall And you were with Ryan…” (imagination + presentation of some plausible information)
““most people can retrieve lost memories if they try hard enough” (social manipulation)
Shaw et al., convinced 70% of participants that they committed a crime
Study was about if you could get someone to faslely remember commiting a crime
imagination exerciences -> induce false memory
was able to convince 70% of the Ss that they comminted a crime
What would we need to understand to mitigate memory errors in the courtroom? What can we do to avoid this?
If we understand how vulnerable memory is, we can mitigate memory errors in the courtroom.
- Improve Interview Techniques
● Avoid misleading questions
● Avoid manipulation
(some of these things are legal depending on where you go)
Be Aware of Who Can Mislead Us
● Partner > Stranger (more likely to be mislead by someone we know)
● Social attractiveness > social unattractiveness
● High power > low power (more likeky to be miss lead by a person of higher power)
- Understand How Confidence Works
● Obtain confidence ratings early
○ Otherwise, “confirmation bias” (gathering information in support of your hypothesis) or rehearsal may inflate later confidence
confidence is uncorrelated to some forms of accuracy
- Education
● Teach people about memory science
educating people about how memory works
- other ppl at ubc do not take courses like this one
What is the thought experiment that is a potential test question?
Possible test question
● You are a juror on a murder case.
● An eyewitness takes the stand and reports their account of the crime.
● How does your knowledge of memory and memory errors affect your use of the
eyewitness testimony?
What were the closing thoughts on this lecture?
● So should we trust an eyewitness? It depends!
(a lot of times in classes like this we think about how eye whitness tests can be disotored
- but there is nauance to this and there )
○ So many factors affect memory and we must wrestle with this balancing act
○ Central versus peripheral
(We tend to remember the central details more accurately)
○ Familiar versus novel (unlikely to show mistaken identity for someone we know)
(- this is extremely relavant for a lot of legal cases)
it is not so simple!
“…a single confident witness might provide enough evidence for conviction if the witness happened to know the accused before seeing the crime or if the witness had extensive opportunities to observe the suspect. Constructing statements of fact that could not be interpreted differently under any set of assumptions would require so many hedges and qualifications that the item likely would not convey the intended meaning (or even be intelligible) to laypeople…”
(We really have to seperate if it is someone known or unknown)
Why is public perception of memory important?
we want to make sure that people have a decent understanding of how memory works
- this is a topic that is imporatant becasue memory is a real world thing for all of us
What Does the Public Believe About Memory?
“Incorrect beliefs about the properties of memory have broad implications: The media conflate normal forgetting and inadvertent memory distortion with intentional deceit, juries issue verdicts based on flawed intuitions about the accuracy and confidence of testimony, and students misunderstand the role of memory in learning.
We conducted a large representative telephone survey of the U.S. population to assess common beliefs about the properties of memory. Substantial numbers of respondents agreed with propositions that conflict with expert consensus…”
Most people underestimate how malleable memory is
Judges and law enforcement professionals know little more than e.g., college students
Amnesia
82.7%
“of respondents agreed that “people suffering from amnesia typically cannot recall their own name or identity.” All 16 experts disagreed”
Confident Testimon
37.1%
“agreed that “in my opinion, the testimony of one confident eyewitness should be enough evidence to convict a defendant of a crime.” All 16 experts disagreed”
Video Memory
63.0%
“agreed that “human memory works like a video camera, accurately recording the events we see and hear so that we can review and inspect them later.” All 16 experts disagree”
Permanent Memory
47.6%
“agreed that “once you have experienced an event and formed a memory of it, that memory does not change.” 15 experts disagreed and 1 responded “Don’t Know/Unclear.””
Unexpected Events
77.5%
“agreed that “people generally notice when something unexpected enters their field of view, even when they’re paying attention to something else.” 13 experts disagreed and 3 agreed”
What is the most common misconception about memory? (David Marchese)
READ SLIDE
What do memory scientistists have to be careful about in temrs of public perception of memory?
As memory scientists, we must be careful not to make blanket statements. Most phenomena are nuanced. Moreover, people differ.
