Forensic cognition

Question 1

Explain how emotions affect memory for gist and details of events

Answer 1

Concentration camp survivors Wagenaar & Groeneweg (1990)
- Marinus De Rijke was accused of nazi crimes in camp Erika in the Netherlands during WWII
- 78 witnesses were interviewed twice in between 1943-1948 (after release) and 1984-1988 (court case)
- Participants exposed to camp conditions for 4-5 months on average
- Data based on court records
- If your only shown 1 photo this is problematic, because your probability of guessing it is 100%
- May answer questions by thinking about what most likely happened (shemas)
Therefore
- Trauma and suffering provide no guarantee that memories for those events will be  entirely accurate  ever-lasting
- Usually, victims correctly recall the “gist” of traumatic events but not specifics

Detail for emotional events
- This is often what judges are looking for details on plates, hair, eye colour, times of day, who said what
- Memory for emotional events is characterised by better memory for the gist but worse memory for the details

Question 2

Discuss how emotions affect the accuracy and reliability of memories, using empirical evidence

Answer 2

“Implanted” memories (e.g., Bernstein & Loftus, 2009)
- Parents provide events from childhood
- Participants interviewed about them
- Plus suggestion of one fictional event (e.g., getting sick after eating egg salad; being lost in a mall; riding a hot air balloon)
- Approx. 30% of participants develop detailed, often vivid memories of fictional event
- Can have impact on behaviour (e.g., less egg salad consumed)

Memory for childhood sexual abuse (Geraerts et al., 2007)
- Individuals were interviewed and there were people with
○ Continuous memories of CSA
○ Discontinuous (recovered) memories of CSA
§ Spontaneous, random and surprising
§ Anticipated recover like in therapy
- Corroborative evidence was sought (e.g., confession, other victims, etc.)
-
- Be sceptical of recovered memories as they can be created and based on suggestion

Summary
- While on average, emotion improves (gist) memory, this can be explained by general memory principles (e.g., distinctiveness), and need not rely on a “special” mechanism
○ Although: Emotion modulates memory through amygdala activation (Phelps, 2004)
- Memory can still fail
○ impaired memory for detail
○ even entirely false memories of emotional events
Perceived reliability of emotional memories is inflated (both introspectively and in public opinion)

Question 3

Explain the terms “flashbulb memory”, “tunnel memory”, and “weapon focus effect”

Answer 3

Talarico & Rubin (2003): Flashbulb memories
- Memory for 9/11 (vs. neutral event) after 1d, 1w, 6w, 32w
- elevated levels of confidence and perceived vividness (i.e. belief in their accuracy) rather than improved accuracy and consistency
- not greater accuracy but greater perceived accuracy
Crombag et al. (1996)
flashbulb-like memories for events that were never witnessed (e.g., remembering seeing a particular plane crash on TV although there was no video footage of the crash)

Weapon focus effect
- If attacker has a weapon, memory for details of appearance is impaired
- This is the effect of emotion (i.e., threat, anxiety)
- Or distinctiveness/salience? Very distinctive event (Mitchell et al., 1998, “celery focus effect”)
- Highly focused on weapon creates an Attentional tunnel

Tunnel memory Safer et al., 1999
- Showed subjects 1 of 2 series of slides
- Identical except for a few slides
- One traumatic (e.g., woman gets throat slashed with knife)
- One neutral (e.g., woman gets handed keys)
- Followed by 4AFC slide recognition and asked which slide they saw in the study condition
- For the emotional condition 34% of participants inaccurately remembered being closer to the emotional event than they actually were
Paid less attention to the details on the periphery

Question 4

Explain the “post-event misinformation effect” and its cognitive basis (i.e. altered memory vs. bias)

Answer 4

Post event information
- Events that happen after the critical even are not neutral
- They often disturb memory
- What does post event information do to the original information?

Misinformation effect Loftus, Miller, & Burns (1978)
- People in the inconsistent group started favouring the wrong answer suggested during questioning
- People absorb suggestive information presented after the event and reproduce it later on
Is this due to altered memory or response bias/strategy?
- To find this there is an unbiased test alternative
- Stop sign in the slides
- Give way sign misleading question
- Then when asked to recollect given the choice of lights or stop sign
- If memory for STOP altered or impaired, misinformation effect should show up even with novel test alternative— and it does, but the effect is smaller (Payne et al., 1994)
- People can have a strategy/bias to report most recent information
- but—as demonstrated by unbiased test—post event misinformation also directly alters memory for event because it…
○ is more recent = stronger (remember temporal distinctiveness?)
○ interferes with event retrieval
○ (or partially overwrites event memory)

Boundary conditions for post event misinformation
- Misinformation needs to be plausible
- Source needs to be credible
- therefore Misinformation effects can be reduced if credibility or believability of source is questioned

Combating the post event misinformation effect
- Public statement early after the events
- Warnings: “Some of the questions contained misleading information”
○ Undermines credibility
○ Increases strategic monitoring
- Timing
○ Vulnerability grows with delay between event and misinformation
Forgetting of event details over time

Question 5

Describe the cognitive interview technique, including its theoretical basis

Answer 5

Police aim to get better information from interviewees based on two theories of memory:
1. Encoding specificity (e.g., Tulving, 1983)
○ Only those cues present at encoding are effective at retrieval
○ Encourage witnesses to reinstate context * What was the weather like? * How were you feeling?
○ What did you smell?
○ Encourage witnesses to recall everything, no matter how trivial—this may cue recall of something important
○ In reality, witness is often interrupted (every ~12s) and recall of trivial details is discouraged

2. Associative network theory (e.g., Bower, 1981)
   ○ Retrieval benefits from activation of as many different pathways as possible
   ○ Repeated recall attempts from different perspectives
   ○ What would someone have seen from the other side?
   ○ What would you have seen as a bird?
   ○ Recall events in varied order
   ○ Proceed forward and/or backward from different points
   ○ Also helps to assess credibility

Effectiveness of the cognitive interview
Geiselman et al. (1985)
- 35% additional material recalled
- No substantial increase in errors
- Accuracy around 90%
George & Clifford (1995)
- Hertfordshire police (U.K.) trained in CI techniques
- Actual witnesses randomly allocated to CI or conventional follow-up interview
- CI secured five times as much information per question as conventional techniques

Problems of the cognitive interview
- Time consuming
- Takes a lot of training
Need cooperative witnesses

Question 6

Discuss measures to reduce the potential for errors in eyewitness identification in line-ups

Answer 6

1. Avoid showing only one person and asking witness to confirm or deny
   ○ high demand put pressure
   ○ High chance of confirmation
   
   2. Warn witnesses tht perp may not be present
      ○ Extremely important and now routinely done
      ○ Reduces bias to make ID and relative judgements
      ○ Otherwise false identifications of up to 78%
   3. Present blank line-up first (all foils)
      ○ Accuracy check: selection of foil suggests “bad” witness
      ○ Blank line-ups do not reduce subsequent willingness to make ID or subsequent accuracy
   4. Blind testing: Person conducting line-up should not know which person in the line-up is the suspect (or at least should not know suspect position in line-up, if line-up blinded)
      ○ Avoids intentional and unintentional suggestion
   5. Take into consideration first-ID confidence only
      ○ Prevents reliance on inflated confidence IDs after contamination through multiple tests
   6. Sequential vs. simultaneous line-ups
      ○ Sequential line-ups reduce relative judgement processes
      ○ But: Sequential line-ups suffer from order effects (Wilson et al., 2019): People’s discriminability reduces with position
      ○ Recent research suggests (e.g., Wixted & Wells, 2017): Simultaneous line-ups are superior if the line-up is fair
   7. Crucial: Ensure fairness of line-up—Suspect must not “stand out”
      ○ Reduces relative judgement concerns
      ○ Ensures first-ID confidence is a reliable indicator of accuracy
      Not easy to achieve…but techniques exist

Question 7

Understand the issues associated with relative judgement and lineup fairness in eyewitness identification

Answer 7

Relative judgement
* identify the person who looks most like the culprit relative to the other members of the lineup
* Not benign because it is subject to bias and stereotypes
Strong evidence for relative judgement, even if crim is not in line up the innocent person who look most similar will be convicted

Question 8

Discuss methods of foil selection and line-up construction

Answer 8

• Suspect-matched
  ○ Pick foils that resemble suspect
  
  • Description-matched
    ○ Pick foils that match description of perpetrator (better)

Suspect matched line up problems
- Only the suspect is “chosen” (=arrested) because they resemble the perpetrator
- The foils are chosen to resemble the suspect (not perpetrator, if suspect is innocent)
- Hence the suspect, if innocent, is bound to be more similar to the perpetrator than the foils are
83% of U.S. police officers use this technique

Question 9

Explain indices of line-up fairness (effective and functional size)

Answer 9

Using mock line up to increase fairness
Two indices (should be maximised)
- Effective Size (ES): Eliminate foils that mock witnesses choose below chance. Mock witness choices should choose an even range of foils. Eliminate lineup if below expected value
○ Line-up size minus Σ[(Exp – Obs) / Exp] * only where obs < exp
- Functional Size (FS): Examine whether mock witnesses choose suspect more than would be expected by chance
Functional Size (FS): Total number of mock witnesses divided by number who choose suspect