Forensic Fluency Assessment and Differential Diagnosis of Malingered Stuttering

Forensic Fluency Assessment: Overview and Clinical Context

• Forensic Application Gaps: There are few published reports describing the forensic application of knowledge related to stuttering and fluency disorders. This is critical for cases that test criteria for differential diagnosis, particularly in distinguishing malingering from authentic disorders.
• Definition of Malingering: Malingering (or feigning) is the intentional production of physical or mental disorder signs/symptoms. The motivation is external gain: obtaining something desirable (money, drugs, insurance settlements) or avoiding something unpleasant (punishment, work, military service, jury duty).
• Pure vs. Partial Malingering:
  • Pure Malingering: All symptoms are falsified.
  • Partial Malingering: Existing symptoms are exaggerated.
  • Denial Malingering: Denying existing symptoms or problems.
• Factitious Disorder Differentiation: Unlike malingering, which has external motivations, factitious disorder is motivated by a desire to occupy a "sick role."

Historical Case Studies in Forensic Fluency

• Shirkey (1987) - Albuquerque, NM:
  • Subject: $33\text{-year-old}$ male accused of molestation.
  • Legal Background: The defendant was previously acquitted because none of the victims reported stuttering, whereas the defendant was known to stutter. Upon re-arrest, the clinician assessed if the defendant could have spoken fluently during the crimes.
  • Findings: Stuttering severity was highly variable. Remarkably, the defendant was fluent in many stressful situations, including police interrogation.
  • Outcome: Fingerprints and eye-witnesses were the primary elements for the guilty verdict, rather than speech assessment.
  • Proposed Evidence Types: Speech assessment under varying conditions, covert audio recordings, polygraph testing, independent testimony (relatives, guards), school/medical records, and observation in conditions typically yielding fluency.
• Bloodstein (1988) - Brooklyn, NY:
  • Subject: Male in his $early 30\text{s}$ accused of armed robbery.
  • Defense Argument: The defendant argued he could not have spoken the words heard by witnesses: ‘‘This is a stickup. Get down on the floor and don’t make a move or I’ll blow your head off.’’
  • Assessment: Analysis of expectancy, adaptation, consistency, adjacency effects, and stuttering loci on content vs. function words. Fluency-inducing conditions included noise and response contingent stimulation (e.g., ‘‘no/wrong’’).
  • Outcome: Responses were typical of an actual stutterer; charges were expected to be dropped.

Theoretical Framework for Malingering and Differential Diagnosis

• Silverman (2004) Protocol:
  • Initial focus on age of onset, symptomatology, and phenomenology.
  • Indirect Process: The clinician asks the client what they know about stuttering. If the client claims ignorance but later defends a exhibited symptom when the clinician questions its consistency, the false claim of ignorance is revealed, undermining the integrity of all behaviors.
• Resnick (1993) Clinical Indicators:
  • Acting and Overacting: Malingerers are "actors" who believe extreme or bizarre behaviors are more convincing.
  • Eagerness: They call more attention to their illness than genuine patients.
  • Contradictions: Discrepancies between stories or between accounts and objective evidence. Malingerers often respond with sulking or laughter when caught.
  • Interview Behavior: Tend to try and take control or act intimidating. They may accuse the clinician of thinking they are faking.
  • Fatigue Factor: Lengthy interviews reduce the ability to maintain deception; rapid-fire questions increase contradictory responses.

Distinguishing Malingering from Conversion Disorders and Psychogenic Stuttering

• Conversion Disorder (Conversion Reaction):
  • Involves involuntary deficits in motor or sensory function suggesting neurological conditions without medical cause.
  • Motivated by unresolved intrapsychic conflict transformed into somatic symptoms.
  • Personality Traits: Individuals tend to be cooperative, appealing, clinging, and dependent.
  • Deception: The individual is in a state of self-deception as well as deceiving others.
  • Accounts: Often provide less generous accounts with omissions and general complaints.
• Comparison with Malingering:
  • Malingerers are often aloof, sullen, resentful, and secretive.
  • Malingerers give exhaustive details about accidents/repercussions to build credibility.
  • Malingering is a conscious intention to deceive others, but not oneself.

Critical Challenges to Detecting Malingered Stuttering

• Inherent Variability: Stuttering is episodic. In actual stutterers, about $90\%$ of speech is fluent on average. Frequency rarely exceeds $45\%$ of syllables except in severe cases.
• Islands of Fluency: Genuine stuttering subsides in specific "fluency-inducing conditions."
• Suspicions of Malingering: A total lack of fluency (stuttering constantly in all conditions) is highly suspicious but must be differentiated from neurogenic and psychogenic stuttering, which also lack "islands of fluency."
• Shared Characteristics of Acquired Stuttering (Neurogenic/Psychogenic):
  • Onset usually in adulthood.
  • Absence of adaptation effect.
  • No pattern of stuttering loci on content vs. function words.
  • Little variability across speaking contexts (e.g., singing, unison).
  • No typical fear, anxiety, or secondary behaviors (e.g., normal eye contact is maintained).

Case Study: Armed Robbery Investigation in the Midwest

• The Participant: Male in his $late 30\text{s}$; high school dropout with a GED; lived only in the Midwest, spoke Standard American English. Reported onset at age $4 \frac{1}{2}$.
• The Crime: Armed robbery at a gas station. Witnesses heard the perpetrator say fluently: ‘‘Lady, give me the money or I’ll shoot.’’
• The Objective: Determine the probability of the defendant being fluent during the crime based on current and past speech patterns.

Assessment Methodology and Fluency Protocol

• Spontaneous Speech Sample: Conversations recording "core" and "accessory" disfluencies.
  • Core Disfluencies: Part-word repetition, monosyllabic word repetition, dysrhythmic phonation (prolongations, blocks).
  • Accessory Disfluencies: Multisyllabic word/phrase repetition, interjection (e.g., "uh"), revision-incomplete phrase.
• Oral Reading Series: Repeated readings of ‘‘The Great Chief’’ passage to measure:
  • Adaptation Effect Formula: $[(\text{percentage stuttered in R1} - \text{percentage stuttered in last reading}) \times 100] / \text{percentage stuttered in R1}$.
  • Consistency Index Formula: $[(\text{number of words stuttered in R1 also stuttered in R2}) \times 100] / \text{total words stuttered in R1}$.
• Fluency-Inducing Conditions Observed:
  • Unison (choral) reading.
  • Whispering, shouting, lipped speech.
  • Automatic/rote speech (counting to $10$, days of the week).
  • Therapeutic probes (finger tapping, slowed syllabic speech).
• Attitude Evaluation: Modified Erickson Scale of Communication Attitudes.
• Information Sources: Jail inmate records (previous and current year), health/medical records, and physician testimony.

Detailed Results of the Forensic Speech Evaluation

• Frequency and Severity:
  • Spontaneous sample ($727\text{ words}$): Overall frequency of $104$ disfluencies per $100\text{ words}$. Core ($50$) and accessory ($54$) were nearly equal.
  • Oral reading ($R1$): $39\%$ of words stuttered (classed as "very severe" where $>25\%$ is the maximum rating on the Iowa Scale).
  • No consecutive utterances were free of stuttering; only $5\%$ ($8/140$) of utterances were fluent, mostly single-word answers.
• Adaptation and Consistency:
  • Adaptation: $4.9\%$ between $R1$ and $R2$, and $0\%$ between $R1$ and $R3$. Group mean for stutterers is $40.54\% \, (SD = 18.3)$.
  • Consistency Index: $51\%$. This is significantly lower than average for stutterers ($M = 69.3\% \, , SD = 14.9)$.
• Patterns and Locations:
  • Stuttering occurred on content words ($50\%$) and function words ($25\%$).
  • Atypical Behavior: The defendant struggled to say interjections (e.g., "umuh") while surrounding words were fluent. He also stuttered on the last words of utterances (e.g., "…thing-thing"), which is rare.
• Fluency Conditions: The defendant stuttered severely in all checked conditions, including unison, whispering, shouting, and automatic tasks. In unison, stuttering became more severe in tension and duration, which is highly unusual.
• Secondary Behaviors: No nonverbal secondary behaviors exhibited; however, he maintained steady, direct eye contact during severe blocks, which is inconsistent with the typical shame/avoidance seen in developmental stuttering.

Analysis of Jail and Medical Records

• Neurological Claims: Jail records noted a "brain aneurysm" and "hypoxic encephalopathy" following surgery $10\text{ years}$ prior. However, health records showed a negative MRI diffusion scan with only minimal inflammatory changes in sinuses.
• Psychiatric Profiles: Records mentioned anxiety attacks, auditory hallucinations, "psychosis nos," and depression. Medications included trazadone, Zyprexa, diazepam, and Prozac.
• Inconsistencies in Fluency Reports:
  • Jail records from the previous year: ‘‘When he is not stuttering, his speech is slow and deliberate.’’
  • Physician testimony: Recalled the defendant speaking fluent utterances of $6 \text{ to } 8\text{ words}$ shortly before the crime.
  • Self-reported history: The defendant insisted he never stuttered less than the amount shown in assessment and that his speech had been the same since age $4 \frac{1}{2}$.

Final Differential Diagnosis and Conclusion

• Developmental Stuttering: Likely present given early onset, core disfluency types, and appropriate Erickson scale score ($21$).
• Partial Malingering (Exaggeration): Identified based on several factors:
  1. Extreme frequency ($104$ per $100\text{ words}$).
  2. Atypical patterns (stuttering on interjections and final words).
  3. Atypical lack of adaptation/consistency index below $1 \, SD$.
  4. Zero improvement in any fluency-inducing condition (especially unison speech).
  5. Direct, relaxed eye contact incompatible with reported apprehension.
  6. Blatant contradiction between self-report (absolute invariability) and third-party observations of fluent periods.
• Acquired Subtypes: Psychogenic and neurogenic forms were suspected but largely unsupported due to early onset history and negative neurological imaging.
• Outcome: The clinician confronted the defendant, stating his responses were "not typical." The defendant did not deny but offered to try tasks again. Ultimately, he submitted a guilty plea and received a lighter sentence.

Questions & Discussion

• Clinician-Defendant Interaction: Upon being told his stuttering was "not typical" and too extreme, the defendant did not become defensive. He asked, "Have I done too many ‘umuhs’?" and requested more time to try tasks like finger tapping, though the $2\text{-hr}$ limit had been reached.
• Implications for Future Research: There is a need for better-designed questionnaires. Future forms should ask, "Does your stuttering improve?" and use numeric rating scales rather than "Yes/No" answers. The term "malingering" should be restricted to clients old enough to have knowledge of the truth (excluding most preschoolers).
• Expert Asset: Valid forensic assessment require clinicians with extensive experience (e.g., over $20\text{ years}$ and Specialty Recognition) to distinguish unique individual variation from deliberate feigning.