Threat-Related Stimulus Exposure for Stuttering

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Memphis

Disqualifiers: Psychological disorders, Neurological injury, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

80 Participants Needed

Trial Summary

What is the purpose of this trial?

The goal of this clinical trial is to examine whether stuttering is associated with a tendency to attend more quickly or for longer durations to threat-related information in the environment (threat-related attention bias). The main questions it aims to answer are: Do adults who stutter, relative to adults who do not stutter, attend to threat-related stimuli more than neutral information? Are attentional biases observed across different types of threat or are they specific to threats related to stuttering experiences? Do measures of attention bias explain individual differences in psychological reactions among adults who stutter?

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, if you have a significant medical history or certain psychological conditions, you may not be eligible to participate.

What data supports the effectiveness of the treatment Threat-related stimulus exposure for stuttering?

The research suggests that people who stutter often experience social anxiety and fear of negative evaluation, which are related to their stuttering. This implies that addressing these fears through exposure to threat-related stimuli might help reduce anxiety and improve speech fluency. ^{1 2 3 4 5}

Is threat-related stimulus exposure safe for humans?

The 'Threat-of-Scream' paradigm, which involves exposure to low-intensity screams, was found to be safe as the screams were neither harmful nor intolerable. This suggests that similar threat-related stimulus exposure methods can be safe for humans. ^{6 7 8 9 10}

How does the Threat-Related Stimulus Exposure treatment for stuttering differ from other treatments?

Threat-Related Stimulus Exposure is unique because it uses exposure to threat-related stimuli, like unpredictable screams, to potentially reduce anxiety associated with stuttering. This approach is different from traditional speech therapy as it focuses on managing anxiety rather than directly modifying speech patterns. ^{7 8 10 11 12}

Eligibility Criteria

This trial is for adults who identify as stutterers, with a mild degree of stuttering or more. They must have normal color vision, speak English primarily, and have at least average nonverbal intelligence and expressive language ability. Excluded are those with significant medical conditions, psychological disorders, reading difficulties, other speech/language disorders besides stuttering, neurological injuries or high scores on depression/anxiety/ADHD scales.

Inclusion Criteria

Additional inclusion criteria for adults who stutter: Self-identification as a person who stutters, Score of at least 11 (mild stuttering) on Stuttering Severity Index, 4th Edition

Normal color vision (based on Ishihara Test, Concise Edition)

Speaks English as their primary language

Exclusion Criteria

Reported significant medical history

Psychological or emotional disorder

Score within clinically significant range for depression on Beck Depression Inventory

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Experimental Tasks

Participants complete three experimental tasks: free-viewing task, dot-probe task, and emotional Stroop task to measure attention bias

3 weeks

2 sessions (2-2.5 hours each)

Follow-up

Participants are monitored for safety and effectiveness after experimental tasks

4 weeks

Treatment Details

Interventions

• Threat-related stimulus exposure

Trial Overview The study investigates if adults who stutter pay more attention to threatening information than neutral data. It explores whether this bias is general or specific to threats related to their experiences with stuttering and if it correlates with individual psychological responses among the participants.

Participant Groups

Group I: Eye tracking tasks Experimental Treatment 1 Intervention

All participants complete three tasks in which they view threat-related and neutral stimuli (words or faces)

Who Is Running the Clinical Trial?

University of Memphis

Lead Sponsor

Trials

73

Recruited

12,000+

University of Alabama, Tuscaloosa

Collaborator

Trials

49

Recruited

17,900+

Findings from Research

A 3-month study involving 9 individuals who stutter showed that repeated exposure to delayed auditory feedback (DAF) significantly reduced the percentage of stuttered words during non-altered feedback (NAF) conditions.

The results indicate that DAF can effectively improve speech fluency outside of a clinical setting, although the relationship between the length of exposure and fluency improvement may not be straightforward.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Delayed auditory feedback in the treatment of stuttering: clients as consumers. Van Borsel, J., Reunes, G., Van den Bergh, N.[2019]

In a study involving 13 adults who stutter (AWS) and 10 adults who do not stutter (ANS), it was found that AWS had significantly decreased lip aperture movement control under external attentional focus conditions, especially during high social stress situations.

AWS exhibited slower tongue movements across all conditions, indicating that social stress impacts their speech motor control, but the type of attentional focus (internal vs. external) specifically affected lip movements rather than tongue movements.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of attentional focus on speech motor control in adults who stutter with and without social evaluative threat. Bauerly, KR., Mefferd, A.[2023]

A study involving 34 participants who stutter and 34 control participants found that those who stutter have significantly higher anxiety related to social situations, as measured by the Fear of Negative Evaluation Scale, indicating a strong expectation of social harm.

The results suggest that anxiety in people who stutter is specifically linked to social evaluation rather than general anxiety, highlighting the importance of using targeted psychological assessments like the Fear of Negative Evaluation and the Endler Multidimensional Anxiety Scales-Trait in clinical settings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Social anxiety in stuttering: measuring negative social expectancies. Messenger, M., Onslow, M., Packman, A., et al.[2013]

Adults with persistent developmental stuttering (PDS) show normal brain responses to simple tone contrasts but exhibit enhanced brain activity in response to phonetic contrasts, indicating abnormal processing of speech sounds.

This enhanced brain response correlates with the severity of speech disfluency, suggesting that the way the brain represents speech sounds may contribute to the challenges faced by individuals with stuttering.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Abnormal speech sound representation in persistent developmental stuttering. Corbera, S., Corral, MJ., Escera, C., et al.[2006]

The Premonitory Awareness in Stuttering Scale (PAiS) is a newly developed and validated tool that effectively measures the anticipation of stuttering events in adults who stutter, showing good internal consistency and the ability to distinguish between those who stutter and those who do not.

Higher scores on the PAiS correlate with fewer stuttered syllables, suggesting that individuals who can anticipate their stuttering may be better at managing their speech disruptions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Premonitory Awareness in Stuttering Scale (PAiS). Cholin, J., Heiler, S., Whillier, A., et al.[2019]

The study involved 13 phobic individuals and 14 control subjects to assess their responses to a threat stimulus using manual muscle testing, revealing poor reliability in the results before controlling for confounding variables.

After adjusting for factors like musculoskeletal and attentional variables, the validity of muscle testing improved significantly to 91%, suggesting that these factors are crucial for accurately measuring emotional arousal in response to threats.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A preliminary inquiry into manual muscle testing response in phobic and control subjects exposed to threatening stimuli. Peterson, KB.[2007]

The 'Threat-of-Scream' paradigm effectively induces anxiety in participants without ethical concerns associated with physical shocks, as it uses low-intensity screams instead.

In two studies, participants showed increased anxiety levels and physiological responses (skin conductance) during threat conditions compared to safe conditions, indicating that this method can sustain anxiety responses over time.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The 'Threat of Scream' paradigm: a tool for studying sustained physiological and subjective anxiety. Beaurenaut, M., Tokarski, E., Dezecache, G., et al.[2021]

In a study with 20 normal volunteers, the anticipation of electric shocks significantly increased the acoustic startle reflex, indicating heightened anxiety levels during threat conditions compared to no-threat conditions.

The fear-potentiated startle effect grew stronger the longer the threat was anticipated, suggesting that anticipatory anxiety intensifies over time, but it sharply decreased once the threat was removed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Measuring the time course of anticipatory anxiety using the fear-potentiated startle reflex. Grillon, C., Ameli, R., Merikangas, K., et al.[2019]

In a study with 9 volunteers, anticipatory anxiety significantly increased the amplitude and decreased the latency of the acoustic startle reflex, indicating that anxiety can be objectively measured in humans.

This method of measuring the startle reflex during anxiety anticipation could help researchers explore the neurobiological mechanisms of anxiety disorders and test potential treatments, leveraging existing knowledge from animal studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fear-potentiated startle in humans: effects of anticipatory anxiety on the acoustic blink reflex. Grillon, C., Ameli, R., Woods, SW., et al.[2021]

The study demonstrated that prepulse inhibition (PPI) can effectively reduce the startle response in rats when a less frequent 'oddball' speech sound precedes a startling noise, indicating its potential for studying complex sound discrimination.

PPI was shown to be a promising method for assessing the ability to discriminate between different speech sounds, providing quicker and more informative results compared to traditional methods.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Differential reductions in acoustic startle document the discrimination of speech sounds in rats. Floody, OR., Kilgard, MP.[2021]

The study found that predictable electric shocks enhanced the startle reflex more than unpredictable shocks, indicating that the predictability of a threat significantly influences fear responses.

Visual cues that did not signal when shocks would occur still increased startle reactions, suggesting that the fear response is dynamically influenced by rapidly changing information about threats, rather than just attention to the cues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Startle potentiation in rapidly alternating conditions of high and low predictability of threat. Mol, N., Baas, JM., Grillon, C., et al.[2019]

The study found that when participants encountered a dangerous object in a previous trial, their reaction times improved and errors decreased in subsequent trials involving dangerous objects, indicating enhanced attentional resource allocation.

In contrast, trials preceded by a safe object resulted in longer reaction times and more errors when facing a dangerous object, demonstrating a motor interference effect that was absent when the previous trial was also dangerous.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A sequential trial effect based on the motor interference effect from dangerous objects: An ERP study. Liu, P., Wang, X., Cao, G., et al.[2021]

References

1. United States pubmed.ncbi.nlm.nih.gov

Delayed auditory feedback in the treatment of stuttering: clients as consumers. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

The effects of attentional focus on speech motor control in adults who stutter with and without social evaluative threat. [2023]

3. United States pubmed.ncbi.nlm.nih.gov

Social anxiety in stuttering: measuring negative social expectancies. [2013]

4. United States pubmed.ncbi.nlm.nih.gov

Abnormal speech sound representation in persistent developmental stuttering. [2006]

5. United States pubmed.ncbi.nlm.nih.gov

Premonitory Awareness in Stuttering Scale (PAiS). [2019]

6. United States pubmed.ncbi.nlm.nih.gov

A preliminary inquiry into manual muscle testing response in phobic and control subjects exposed to threatening stimuli. [2007]

7. England pubmed.ncbi.nlm.nih.gov

The 'Threat of Scream' paradigm: a tool for studying sustained physiological and subjective anxiety. [2021]

8. United States pubmed.ncbi.nlm.nih.gov

Measuring the time course of anticipatory anxiety using the fear-potentiated startle reflex. [2019]

9. United States pubmed.ncbi.nlm.nih.gov

Fear-potentiated startle in humans: effects of anticipatory anxiety on the acoustic blink reflex. [2021]

10. United States pubmed.ncbi.nlm.nih.gov

Differential reductions in acoustic startle document the discrimination of speech sounds in rats. [2021]

11. Netherlands pubmed.ncbi.nlm.nih.gov

Startle potentiation in rapidly alternating conditions of high and low predictability of threat. [2019]

12. United States pubmed.ncbi.nlm.nih.gov

A sequential trial effect based on the motor interference effect from dangerous objects: An ERP study. [2021]