Lecture 11 - Forensic Testing (DN) Flashcards
1
Q
What is required of the forensic Neuropsychologist?
A
- must demonstrate a causative link between
- cognitive impairment & the event in question
2
Q
What kind of Battery should be used in a Forensic setting?
A
- A fixed battery
- ensures replicability
- observations can be backed up
3
Q
Where did the Daubert standard come from?
A
- Daubert was suing a pharmaceutical company
- believed medication mother took during pregnancy caused cognitive deficits
- supported by animal studies
- problem was they couldn’t support with human studies
- led to strict guidelines for forensic assessment
4
Q
What is the Daubert standard:
A
Standards expected for forensic testing; resulting from outcome of Daubert case.
Validity of methods are judged by
- the experts methodology must be testable
- the technique should not rely on subjective interpretation by the expert
- the theory must have been peer reviewed
- the underlying theory or technique should be generally accepted by relevant scientific community
- the techniques potential rate of error should be low
- non judicial uses of the theory or technique are also considered
5
Q
What is the “Motion to Exclude” controversy?
A
- Various batteries, including flexible batteries do meet legal requirements if administered & interpreted properly
- the HRB is very widely used & papers published have been used by defense attorneys to exclude other approaches
- In reality - the HRB is not the only valid battery, but scientific papers are often used to imply this
- in particular it is often used to discredit flexible approaches
6
Q
What special considerations should be made in a Forensic Neuropsychological Assessment?
A
- Interview Approach
- General Assessment Approach: Selection and Administration of Instruments
- Estimation of Premorbid Functioning
- Detection of Malingering
- Ecological Validity (apply to real life impact)
7
Q
What are the goals of a forensic interview?
A
-
establishing causal link between deficit & legal consideration (not documenting deficit)
- e.g., Rodney King case (riots - sued for police brutality, could not prove causality)
- focus on inconsistencies
- aided by multiple sessions
- focus on dynamic evolution of symptoms
- discard alternative accounts
- confirm reported symptoms align with impact on everyday activities
23:30
8
Q
How does a forensic psychologist establish premorbid functioning?
A
premorbid functioning must be reported in forensic settings
forensic neuropsychologists utilise:
- Records: School, Military
- History and Collateral Interview
- Resistant (crystalised) skills
- reading, writing, vocabulary, attention for familiar scenes or pictures
- Demographic variables
- e.g., rural vs city, education
- Resistant*Demographic
- combining resistant & demographic info
- “Best performance”
- Include personality assessment
9
Q
How could a Forensic Neuropsychologist estimate premorbid IQ?
A
- no 100% reliable methods
- combine methods
- use proxi’s of IQ
- access records (school etc)
- work position etc
- collateral interviews
- reading ability is also good indicator of IQ
- all combined should provide a good picture of premorbid IQ
10
Q
What psychometric properties should be considered when selecting instruments in forensic settings?
A
- Norms
-
Sensitivity
- accuracy to detect (signs of) existing conditions
- detect malingering
- accuracy to detect (signs of) existing conditions
-
Specificity
- accuracy to discard (signs of) non-existing conditions
- do not want to falsely classify a malingerer if they are not
- accuracy to discard (signs of) non-existing conditions
14:40 & 45:00
11
Q
What is involved in the administration of instruments in forensic settings?
A
- multiple sessions (schedule in advance)
- rapport
- record exact dates, times, rapport, sequence of instrument administration
- stick to standard test instructions
- clearly record test outcomes, timings in timed tests
12
Q
What is malingering?
A
- Intentional production of false or greatly exaggerated symptoms
- to attain some identifiable external reward
(Iverson & Binder, 2000)
47:50
13
Q
According to the DSM-IV-TR, what are some symptoms often presented by a malingerer?
A
- Physical symptoms (e.g., low back pain)
- Psychological symptoms (e.g., psychotic)
- Neurocognitive problems (e.g., poor memory)
14
Q
What is a very important early step in forensic evaluations?
A
- Clarify the referral question
- be aware of external gains
- frame referral
15
Q
What should be present before diagnosing Definite Malingered Neurocognitive Dysfunction (MND)?
A
- Presence of a substantial external incentive
- Definite negative response bias
- the Negative response bias cannot be otherwise accounted for
16
Q
What two criteria are used when performing a differential diagnosis of malingering in forensic settings?
A
- Control over Behaviour
- External Reward
54:00
17
Q
What should be present before diagnosing Probable Malingered Neurocognitive Dysfunction (MND)?
A
- Presence of a substantial external incentive plus
- > 2 types of NP evidence (not including negative response bias)
or
- 1 type of NP evidence plus 1 type of evidence from self-report
- Behaviors cannot be otherwise accounted for
18
Q
What are three Malingering Assessment Methods?
A
- Specific tests
- appear to be testing something else, but actually designed to detect malingering
- material is well protected - to minimise cheating on these tests
- Pattern analysis of standard tests
- does pattern of performance align with symptoms
- Detection of inconsistencies
1:09:30
19
Q
What type of inconsistencies does a forensic psychologist seek to detect?
A
Inconsistencies
- Within reported symptoms (different moments)
- Between reported and recorded history
- Between reported symptoms and actual behaviour
- Between reported symptoms and collateral information
- Between reported symptoms and performance on tests
- Between expected scores (considering type and severity of dysfunction) and actual scores
- Between tests scores and behavioural observations or everyday activities
- Between tests scores and collateral reports
- Between neuropsychological domains
- Between repeated testings
141:30
20
Q
- What are some forms of Standard Test Pattern Analysis?
A
- Easy vs. Difficult Items
- Indices measuring similar domains
- Attention vs. Memory
- Recency and Primacy effects
- Free recall vs. Recognition
- Implicit Memory tests
21
Q
What are some ‘fair’ reasons that people may try to exaggerate or underperform on an assessment?
A
-
Assessment conditions
- Inadequate assessment conditions, poor rapport
- prison, refugee, cultural, communication difficulties
- Inadequate tests – culture, language
- Inadequate assessment conditions, poor rapport
-
Trait characteristics
- Cognitive distortions
- Somatisation, Hypochondriasis
- Conversion Disorder
-
Condition/Litiation specific states (e.g., may go on for years)
- Stress, Pain
- Bad sleep, Fatigue
- Medication, drug use
57:00
22
Q
How could these ‘fair’ exaggerations be handles without labelling the peron a malingerer?
A
- Ensure “fair” assessment conditions
- Analyse Records, History (e.g., “hospital records”, “family history – somatisation”)
- to look at impact on client presentation
- Diagnostic Tools
- Trait/State self-reports: Mood, Stress, Sleep, Fatigue
- Biomarkers
- e.g., in drug use, check if drug in blood
100:20
23
Q
What should a forensic neuropsychologist considered if Drug Use is suspected to be contributing to an over exaggeration of symptoms?
A
- Patterns of use
- Severity of dependence
- Withdrawal
- Craving
- Drug testing
- Saliva
- Urine
- Hair
24
Q
What are some other disorders (other than malingering) that should be considered when faced with an exaggerating client?
A
- Factitious disorder
- Somatoform disorder
- Depression
- Personality Disorders
- Dissociative Identity Disorder
25
What is negative response bias?
performance below chance
normally when someone is purposely performing poorly (e.g., in malingering)
1:08:00
26
What is the Rey test?
* Rey 15 items
* a malingering test
* based on floor effects
- create perception it is difficult, by saying this is a difficult task, but try your best!
- it is actually difficult to get it wrong
sensitivity 49% - not that good - as most malingerers would get more than 9 correct (perhaps because it is a little too obvious that it is a malingering test???)
specificity - good - wouldn't have false positives as most people not trying to malinger would do it right
27
What is the main focus of malingering tests?
identify best combination of tests to maximise sensitivity & specificity
28
What are some features of '**Specific Tests' **used to detect Malingering?
* Based on floor effects (15 items)
* Based on overlearned skills (Dot Counting)
* **Forced choice recognition** (VSVT, TOMM)
* Victoria Symptom Validity Test (stimuli, then blank screen, then two stimuli - choose)
* Test of Memory Malingering (booklet - 50 stimuli - present at beginning as most difficult to remember 50 items). - as its forced choice (recognition) is much easier than free recall
* More complex presentations, multiple domains
* Forced Choice vs. Simplistic
* Empirical cutoffs vs. Binomial distribution
29
Which Tests have **sensitivity greater than 85%?**
**FORCED CHOICE TESTS**
* **Digit Recognition**
* Victoria Symptom Validity Test (VSVT)
* **Visual Recognition**
* Test of Memory Malingering (TOMM)
* **Word Recognition**
* Word Memory Test (WMT)
30
Which of the Forced Choice Tests have sensitivity between **70 - 84%**?
**FORCED CHOICE TESTS**
* **Digit Recognition**
* Digit Memory Test (DMT)
* **Visual Recognition**
* Letter Memory Test
* 48-Pictures Test
**SIMPLISTIC TEST**
* The b Test
31
Which of the Tests have sensitivity between 50-69%?
**FORCED CHOICE TEST**
* **Verbal & Nonverbal Abilities**
* Validity Indicator Profile (VIP)
32
Which of the Forced Choice Tests have **sensitivity less than 49%**?
**FORCED CHOICE TESTS**
* **Digit Recognition Test**
* Portland Digit Recognition Test (PDRT)
* **Word Recognition Test**
* 21-item Test
**SIMPLISTIC TESTS**
* Rey 15-item Test
* Dot Counting Test
33
Specificity \>85%
**FORCED CHOICE TESTS**
* **Digit Recognition**
* Digit Memory Test (DMT)
* Portland Digit Recognition Test (PDRT)
* Victoria Symptom Validity Test (VSVT)
* **Visual Recognition**
* Test of Memory Malingering (TOMM)
* Letter Memory Test
* 48-Pictures Test
* **Word Recognition**
* 21-Item Test
**SIMPLISTIC TEST**
* Rey 15-Item Test
34
Do current malingering tests fall short on sensitivity & specificity?
Specificity is optimal in many tests
Sensitivity is not so good
e. g., Rey test has good specifiity and not good sensitivity
128: 15
35
What are 'low sensitivity' tests usually based on?
* Floor effects
* overlearned skills
36
What features do tests with Good Sensitivity and Excellent Specificity usually have?
* Forced choice recognition
* More complex presentations,
* multiple domains
37
Which two tests have the best numbers for sensitivity and specificity?
TOMM and VSVT
38
Other than sensitivity & specificity; what else should be considered when testing for malingering?
* the **Predictive Value (PV)** of the test
* PV is the capacity of the test to actually decide if the person has or has not the disorder or not
* While sensitivity & specificity are **not** impacted by the prevalence of the condition in the population, **PV is heavily influenced** by base rates (prevalence)
* e.g., base rates - Neuropsych patients 15% / Criminal case 54%
* calculations at (1:32:20) on lecture (don't think need to know them though)
1: 30:00
39
What three factors should be most highly considered when selecting a test of malingering?
* Sensitivity
* Specificity
* Predictive Value
40
What is another way of checking for malingering?
Pattern analysis of other standard tests
* Easy vs. Difficult Items
* Indices measuring similar domains
* Attention vs. Memory
* if one is good the other most likely should be good
* check for consistency
* Recency and Primacy effects
* Free recall vs. Recognition
* if recognition is performed worse than free recall - this would be suspicious
* Implicit Memory tests
* normally preserved even in brain dysfunctional population
41
What indices would be used to detect Malingering using Pattern Analysis in Standard Tests?
Pattern Analysis
* **WAIS: Digit Span**
* Malingerers: Low digit span performance (\< 4) ***(below 4 is unusual)***
* Reliable Digit Span (sum of longest correct span for both trials \< 7) ***(below 7 unusual)***
* Vocabulary–DigitSpan(low digit span while vocabulary is high) ***(t-scores should be similar)***
* **Wechsler Memory Scale**
* Malingerers:Attention/Concentration\< General Memory
* *(memory would usually be worse)*
* Opposite pattern to typical head injury
* **Verbal learning** (e.g., California Verbal Learning Test)
* Malingerers: Low recognition (hits & forced-choice)
* Cutoff scores for recall trials produce variable false-positive rates
* **Word Memory Test**
* Malingerers:Inconsistentresponding,poorinitialrecognition
* Pattern should reflect severity of impairments
* **Category Test**
* Malingerers:Poor performance on first 2 subtests
* **Wisconsin Card Sorting Task**
* Malingerers: Poor ratios of categories completed compared to
both perseverative errors and failure to maintain set
* Non-perseveration errors \> Perseveration errors
* **Motor Functioning**
▪ Malingerers: Suppress motor functioning to extreme levels
▪ Motor decline should only be associated with severe brain injury
136:35
42
Why would an individual exaggerate symptoms (via self report)?
* May not be intentional
* May be due to other variables (i.e., depression, pain, stress)
* e.g., Post-Concussive Syndrome persisting for more than 3 months
1:43:40
43
How can malingering be detected through standard tests?
* Some standard tests detect malingering e.g., MMPI-2
* Malingerers tend to show elevations in clinical scales 1, 2, 3, 7, and 8,
* the Fake Bad Scale (FBS),
* VRIN
* TRIN
* the Infrequency-Psychopathology Scale [F(p)].
* The F Scale and F – K does not appear to be as sensitive, and therefore “valid” profiles may be obtained.
* Caution should be given to interpreting the clinical scales and F Scale derivatives, as these can be easily influenced by psychiatric comorbidities
44
How can the **ecological validity** of a forensic assessment be improved?
When choosing assessment tools
* Emphasise Verisimilitude over Veridicality.
* **Verisimilitude** - tries to make tests very similar to real life situation (e.g., key search test from last week)
* **Veridicality** - more pragmatic (practical) - about doing research on the predictive validity of classical tests
* Clearly define outcomes
* define as different levels rather than (yes can work or no can't work)
* Prioritise memory, executive & motor measures (better prediction domains)
* Consider test properties & previous evidence
* up to 51% variance explained (this is where we are at now)
45
What are important considerations in the administration of the assessment?
* Establishing Rapport
* provide best possible conditions for assessment
* Schedule Multiple Sessions
* Record dates, times, rapport, sequence of tests
* Stick to standard test instructions
* Clearly record test outcomes & timing in tests
* also record the way the patient is coping etc
* this minimises risk of subjective
46
What are some important considerations when administering tests for malingering?
* Always first
* if detect malingering, then rest of tests would be invalid
* Use multiple tests
* Adjust predictive value to number of tests
* try to maximise
* Consider face value of multiple presentation modalities
* people will normally try to malinger obvious thing (like memory)
* other tests like executive function (better disguise the test)
1:50:00
47
What are some guidelines for **interpretation** of the tests?

* Consider ALL sources: History, Observations, Tests, Collaterals info, Clinical Judgment
* don't jump to conclusions from one tests
* Avoid subjective signs (observations, complaints)
* lack of scientific evidence regarding validity
* If there is evidence of malingering
* All other NP tests patterns should be considered invalid
* Always use probabilistic/descriptive language in reports
* (use diagnostic descriptors fron Slick, Sherman e Iverson, 1999; X% probability of malingering according to X)
* can't label someone a malingerer
* Provide extensive referencing for your statements in reports
151:15
48
What are some of the **challenges** faced when testing for malingering?
* Inherent complexity of the assessment
* Protection of specific tests
* Coaching from lawyers
* Replicability
152:50
49
What is the difference between a patient who is 'lying' and one who 'lacks awareness' or is in 'denial'
A patient who is lying has
* purposeful intention
* cognitive control
* very different to awareness or denial
* can use objective markers of lying
* e.g., fMri - shows cognitive effort involved in lying
153:50
