Memory in the Courtroom; Public Perception of Memory Flashcards
Eyewitness Testimony
- 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
- 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
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)
Pros and Cons of a Constructive Memory?
Pros:
○ Allows us to “fill in the blanks”
○ Cognition is creative
○ Understand language
○ Solve problems
○ Make decisions
○ Cons
○ Memory errors
■ False beliefs about others
■ Susceptibility to misinformation
Knowledge, Experiences, and Expectations
-
Schema: knowledge about some aspect of the environment
– You know what a post office, ball game, or classroom should look like -
Script: conception of a sequence of actions that usually occurs during a particular experience
– Going to a restaurant; playing basebal
script differently then schamas but scrip is what occurs in a particular experience
Schemas and Scripts
- 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
- Error Type 1: Source monitoring error
-
Source memory: determining origins of our memories
(who,when,where,what,how the memroy comes from) -
Source monitoring error: misidentifying source of a given memory
– Did I mention this in this section or the other one?
study
Source Monitoring: Becoming Famous Overnight
Encoding: (everybody got this)
* 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
Explanation:
ome non-famous names were familiar, and the participants misattributed the source of the familiarity. Failed to identify the source as the list that had been read the previous day
this is important because eyewitness are usually interview after some time so their memory are more sustable to mistribution
Error Type 2: 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
-when paying attention to something else, witness dont notice a crime
-or do not recognize who did the crime which might lead them to fill in the blanck with something else(that might be wrong)
Error Type 3: Errors due to suggestion
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
Suggestion: The Misinformation Effect - experiment
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?
result: “smash” group much
more likely to report a faster speed and the presence of broken glass
misinformation effect:
misleading information presented after someone witnesses an event can alter how that person later remembers
the event
People of all ages are prone to the misinformation effect but some data
suggests it is stronger in children and older adults.
Implanting False Memories
- If participants are givena 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
Implanting False Memories
implanting a crime
“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
Relevance
If we understand how vulnerable memory is, we can mitigate memory errors in the courtroom.
1. Improve Interview Techniques
● Avoid misleading questions
● Avoid manipulation
* using neutral question
* be aware of who can mislead us
1. Improve Interview Techniques: Be Aware of Who Can Mislead Us
● Partner > Stranger
● Social attractiveness > social unattractiveness
● High power > low power
2. Understand How Confidence Works
- Obtain confidence ratings early(right after it heppened)
○ Otherwise, “confirmation bias” (gathering information in support of your hypothesis) or rehearsal may inflate later confidence
3. Education
● Teach people about memory science
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?
Closing Thoughts
Important!!!!
● So should we trust an eyewitness? It depends!
○ So many factors affect memory and we must wrestle with this balancing act
○ Central versus peripheral
○ Familiar versus novel (we are unlikely to show mistaken identity for someone we know) (a person you know vs a stranger)
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
First, Why PUBLIC
PERCEPTION OF
MEMORY Is Important?
- eyewitness
- combat ageism
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.
Substantial numbers of respondents agreed with propositions that conflict with expert consensus…”
