Memory in forensic psychology

Investigative process

The investigative process is contingent on gathering information from human memory

• Investigators then make decisions based on accounts gained from people's memory

• All investigations, reviews and enquiries rely on the testimony of witnesses

• All witness testimony is reliant on the underlying memory processes.

Why is research important?

• Wrongful convictions: Wells et al (1998; Law & Hum. Behav.,22(6), 603-)

• "..mistaken eyewitness identification is responsible for more of these wrongful convictions than all other causes combined." (p.605)

• 40 cases where DNA evidence proved innocence

• 36 of these cases involved at least 1 eyewitness

• Wells, et al (2006: Pscy. Sci. in Public Interest, 7 (2), 45-75): 180 definitive DNA cases of wrongful conviction, 75% involved eyewitnesses: Innocence Project

BACKGROUND

Munsterberg (1908): "On the witness stand"

• Proclaimed the superiority of psychology to lawyers common sense

• Probably no relationship between accuracy of eyewitness and confidence'

Cognitive revolution 60s - 70s

• Neisser & Winograd (1988): Ecological approaches to memory

• Applied eyewitness testimony research

• Loftus & Palmer (1974): Post event factors

• Wells (1978) System-Estimator Variables

Much of this research currently endorsed by experts. Kessin et al (2001)

MEMORY IS NOT A RECORDING

Encoding can be affected by a number of different elements including:

• External factors

• Internal factors

• Perspective

• Bias

• Perception

Memory is not a recorder where all we have to do as an interviewer is reach for the play button. Memory is a construct formed of a complex number of influences.

External factors: Duration of exposure to event, object, person; frequency of exposure; physical factors, such as illumination, obstructions, distance; salience (is it if interest to the observer; gravity of offence; weapon focus more on this later Internal factors: Divided attention; personal relevance; mood, emotion, stress, dissociative symptoms (sexual offences), distortions (Private Ryan effect)

Psychological issues; substance effects; traumatic injury

Types of memory

Procedural - tasks eg picking up cups

Semantic - facts etc

Episodic - events

• Episodic memory does not work like a video recorder!

• Made up of lots of pieces of related information

• What happened, person descriptions, and related information such as emotions, thoughts, whether we saw/heard/read something.

• People can and do make mistakes!

YERKES DODSON LAW RELATIONSHIP BETWEEN AROUSAL AND PERFORMANCE

Yerkes, R. M. & Dodson, J. D. (1908). The relationship of strength of stimulus to rapidity of habit formation. Journal of Comparative Neurology and Psychology, 18, 459-482.

Easterbrook Hypothesis:

• Range of cues attended to is inversely related to degree of arousal

• Describes the 'tunnel effect' where central details are remembered over peripheral

• As arousal increases, attention narrows and fewer environmental stimuli are attended to (range attention decreases, focuses)

When arousal is low or too high, performance is weak.

ENCODING FACTORS - STRESS AND ATTENTION

Stress associated with worse recall - Valentine & Mesout (2009)

Mock POW camp as training. "Prisoners" susceptible to false information - Morgan et al. (2013)

Observers have better recall than those directly at risk in simulated armed police operations - Hope et al. (2016)

Witnesses to a real crime showed a positive relationship between stress and accurate recall even after 5 months- Yuille & Cutshall (1986)

ENCODING FACTORS - ATTENTION AND STEREOTYPING

Weapon focus (Fawcett et al., 2013)

• "Of Guns and Geese"

• Tendency to forget other details when a weapon is present

• Effect reduces with exposure

Stereotyping (e.g. Tuckey & Brewer, 2003)

• Tendency to misremember schema incongruent information about crimes

Fawcett - Our findings indicated an effect of weapon presence overall (g = 0.53) that was significantly influenced by retention interval, exposure duration, and threat but unaffected by whether the event occurred in a laboratory, simulation, or real- world environment.

NON-DECEPTIVE FACTORS AFFECT THESE PROCESSES

• Stress

• Emotion

• Age

• Disease

• Disability

• Neurodiversity

• Poverty

• Mood

• Mental Health

- These factors affect the everyone involved in the process, complainants, witnesses, suspects, and investigators

ENCODING FACTORS - INTOXICATION

• Alcohol: Usually associated with fewer details and might be associated with a tendency to focus on central features

• Other drugs: Harder to study

• Vredeveldt et al. (2018): Amsterdam "Coffee Shop" users remembered fewer details about a mock crime video when recruited leaving than when recruited entering.

EMOTION

Deffenbacher (1983;In Bostock & Clifford (Eds), Evaluating witness evidence, Wiley.)

• 10 studies show increased (or stable) accuracy with higher arousal levels, while 11 show the opposite: lower accuracy with increased arousal

Deffenbacher et al (2004 Law and Human Behavior, 28(6),687-)

• Meta analysis - 27 tests of perpetrator identification and 36 tests of recall for details of crime.

• High levels of stress impaired accuracy and recall on both types of eyewitness memory.

EXPOSURE DURATION

Shapiro & Penrod (1986; Psych. Bull., 100 (2), 139-156) meta-analysis

•Linear relationship: hit rate increases with increases in time spent viewing a target. However, increased exposure to faces increased false alarm rates.

Read (1995; Applied Cognitive Psychology, 9,91 - 21.)

•Suggested that longer exposure may bias people's assumptions about what they ought remember. Found that in Target Present line-ups longer exposure was associated with accuracy, but in Target Absent, with increased false alarm rate.

Memon, Hope & Bull (2003; Brit.Jour. Psyc, 94, 339-354)

• Simulated crime. Witness exposure manipulated (12s vs 45s)

• Longer exposure associated with accurate identification and accurate rejection

• Longer exposure also inflated witness confidence

WITNESS CONFIDENCE DOES NOT CORRELATE WITH ACCURACY jurors think it does!

• Retrieval & the barriers to remembering

Retrieval is simply the process of accessing information from memory storage The process of retrieval can suffer 'interference', both Retroactive interference & Proactive interference

Retroactive interference

• Occurs when new information disrupts or 'contaminates' the information to be remembered
  A witness's recall may suffer retroactive interference and become contaminated by information gained post-incident from speaking to other witnesses, police, emergency services, reporters, family, etc
  The recall may also suffer interference through poor questioning techniques, or by an interviewer asking a poorly framed question

misinformation effect

• The misinformation effect is a prime example of retroactive interference, which occurs when information presented later interferes with the ability to retain previously encoded information.

• The misinformation effect has been studied since the mid-1970s. Elizabeth Loftus is one of the most influential researchers in the field. It reflects two of the cardinal sins of memory: suggestibility, the influence of others' expectations on our memory; and misattribution, information attributed to an incorrect source.

Post event information

Can alter the original memory. Whether from others witnesses, investigators etc or from media material.

It can act as a retrieval cue to activate new recall or it can act as a contamination and 'overwrite' memory.

They may compromise their memory to align with the content of the PEl.

The misinformation effect is one of the most robust experimental findings in Psychology Does misinformation impair memory for originally - witnessed detail? There is some evidence although effects are small and inconsistent. It is not known whether the effects are permanent or reversible

Proactive interference -

Occurs when old information or memories interfere with new information Can be problematic when a witness's memory for old information taints their recall of a recent event

Barriers to Retrieval

• Distraction at the time of encoding

• Trauma

• Age

• Lack of concentrated effort at recall

• Passage of time

Context Reinstatement

Research has shown that memory retrieval is most efficient when the context of the original event is reinstated at the time of recall (Tulving & Thomson, 1973)

•Prior to inviting an episodic recall from a witness, their recall can be assisted by mentally recreating the external environment and their cognitive and emotional states that existed at the time of encoding

Retrieval

• Memory is fragile and can be contaminated through poor investigative techniques.
  Treat memory like a crime scene and tread carefully!

• Memories can only be retrieved if they were encoded to memory in the first place

• Eye-witnesses evidence tends to be recovered from Episodic memory

• Investigators can assist witnesses to retrieve information by re-establishing context

What are some ways we can retrieve memory

Question

free recall

serial order of events

temporal order

group by categories

cued- recall.

MNEMONIC PROMPT

Critical: Allow them to feel in control the narrative

Research has shown that inviting an interviewee to recall details in category clusters can help to increase information yield.

•Example: 'Please tell me everything you remember about Location x. Even if you think it might be irrelevant or that it's something that I already know about.
Take the time you need and tell me everything that you can remember.'

Potential category clusters of interest:

• Person details

• Action details

• Location details

• Object details

• Conversation details

• Sound/ sensory details

Crime Scene contamination is not restricted to the physical environment.

• The theme of the presentation is memory research and how police activity with witnesses has the same ability to impact evidence as poor crime scene management.

• We don't enter crime scenes without following guidance to preserve evidence and avoid destroying, damaging, degrading, altering evidence. The same principles should apply when considering witness evidence including cross-contamination!

Witnesses require three interdependent mental processes:

• Attention

• Perception

• Memory

EPISODIC MEMORY AND THE HIPPOCAMPUS

The hippocampus is required for:

• Encoding and recalling long term memories

• Encoding and recalling episodic memories

• Placing memories in context

• Knitting together incoming sensory information with the context, or backdrop, in which the memories were formed

• Spatial navigation: human GPS

EXPLORING EPISODIC AND EMOTIONAL MEMORY

Episodic memory involves recalling events in one's personal history such that one can provide details about people and objects present during specific events and the locations in which particular events occurred (Wang, Yonelinas, & Rangnath, 2013;
Good, Barnes, Staal, McGregor, & Honey, 2007).

Repeated recall

• Likely to happen in forensic contexts.

• Variability across interviews may be due to omission (and metacognitive factors).

• May also be due to contradictions in repeated reports of single events (bearing in mind repeated interviews may be needed to elicit full and accurate testimony, what are the costs?).

• Contradictions appear to arise from loss of availability of original response, irrespective of its accuracy.

• Longer delays should increase effect because of increased forgetting or inaccessibility.

• Dealt with practically by allowing witnesses to re-read statements.

Removed from repeated events to repeated recall of events - looking at the number of times of repeated recall

1. Friend family

2. Police call operator

3. Initial reporting officer

4. Secondary investigator (may be more than once- statement, interview etc) could be over period of time

5. Discussions that take place outside the context of investigation i.e. friends family

6. Process after charge- may go into counselling, medical attention, victim support

7. May give evidence in court

8. Contradictions appear to arrise from loss of availability etc - this stems upon the clients confidence regarding the information in their recall- are they recalling the original event or recalling their previous recall? There are a lot of well founded reasons why contradictors may appear- this does not necessarily discredit the
   witness testimony = each time you tell it there will be parts that come back to you and some parts that don't have much emphasis- some things may seem more apparent in one interview as you remember you didn't remember it in last interview

   9) Last point- good for events that happened some time ago as their memory was fresh when they made the statement

CENTRAL VS PERIPHERAL DETAILS

• For the witness, what they consider central is likely to be the details that give the event meaning.

• From the forensic point of view, central details would be details that would help catch and convict a perpetrator eg. Descriptions.

• Not always compatible.

• Studies are fraught with difficulties over these distinctions.

From a forensic perspective what is likely to be of central importance is the car registration number, description of driver etc. The witness might further give meaning by ascribing some stereotypical details to the driver.

INVESTIGATIVE CONSIDERATION - DELAY

If an event is recognised as crime (e.g. hit and run) the initial interview is often very quick. Trial may be some months/years later.

Some crimes not recognised as such until later e.g. fraud, child sexual abuse (CSA).
Initial interview is much delayed.

'Overlearned' events very reliable after time (e.g. words learned for school play, street names from childhood). Forensic memories are not generally 'overlearned' in this way. Relates to intentional versus incidental learning.

• This shows that if the event is recognised as a crime straight away then the interview may happen quite quickly but if not then can take a while and the memory wont be rehearsed over time and it will decay. May start off as verbatim memory but end with gist memory.

• Overlearned memories are things that you've INTENTIONALY tried to learn which doesn't usually take place in most forensic settings

Fine grain detail

These are specific details from memory that would fit with verbatim memory

Coarse grain detail

These are more general details that will form gist memory and be more stable over time

Gist memory

approx. = coarse grain size

• General details about event

• Long lasting

• Most likely to be elicited via free recall

• Vulnerable to schema-consistent distortion

Verbatim memory

(approx. = fine grain size)

• Specific details about event

• Liable to rapid decay

• May need to be elicited via cued recall

• Vulnerable to leading/misleading questions

Place cells

representations of episodic memory

Metamemory processes.

• Reality monitoring and source monitoring relate to our ability to differentiate between potential sources of information - imagined or real

• Distinctiveness heuristic: if an event is not distinctive in its nature to separate it from its other events, it may be unreported

• When such processes fail to reject false information, incorrect information may be given. They may also lead to the rejection of true information

RETRIEVAL: RECONSTRUCTIVE

• Links to constructive memory and schemas.

• •In addition to remembering information which is consistent with schemas for a given event, memory can be affected by perspective, imagination, beliefs, knowledge, self-esteem etc.

• Links to constructive memory and schemas- schemas and memory can change since the first ever recall due to anything such as speaking with friends, news, etc

• It is reconstructive because when you recall an event over a few times, each time you are actually recalling the recall than the original memory.

A MORE MODERN WAY TO EXPLORE LONG TERM MEMORY: MEMORY PROCESSES

• Different brain regions are recruited dependent on the information available, the context in which memories are encoded and retrieved, and factors such as stress or trauma history.

• The emotional state of an individual at the time of an event will impact how it is encoded, remembered, and later recalled.

• Emotional state impacts the encoding of episodic memories. Episodic encoding by hippocampus affects amygdala response to subsequent emotional stimuli (Phelps,
  2004)

• Differential neural activation patterns for emotional and neutral episodes (Smith, Henson, Dolan & Rugg, 2004)

THE ROLE OF EMOTIONS AND EPISODIC MEMORY IN INVESTIGATIVE INTERVIEWING

What one encounters on the other side of the table is impacted by their emotional state at the time events were encoded, the state you find them in during interview, and all the times they have recalled the events) in between.

Considering emotional processes when considering how episodic memories are recalled provides a more comprehensive account of events (Talmi, 2013).