ClinicalTrials.gg
RecruitingNCT06420557DecNefUpdated Oct 5, 2026

Unconscious Reduction of Fear Through Decoded Neuro-Reinforcement

An interventional study of Unconscious Neuro-reinforcement and Unconscious Neuro-reinforcement in Phobia, sponsored by University of California, Los Angeles. Recruiting at 1 site in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-05.

Sponsored by University of California, Los Angeles · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Started Sep 2024; still recruiting 2 years 2 months later.
Updated Oct 5, 2026Primary completion movedStudy completion movedGo to Updates ↓
Phase
Not applicable
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

This application investigates the efficacy of a novel method of neuro-reinforcement based on decoded fMRI activity to reduce fear responses in individuals with phobias (e.g., spiders, snakes). This method works unconsciously in the brain, without the need for participants to endure repeated conscious exposures to their feared stimuli. Fear-related disorders such as specific phobia, post-traumatic stress disorder (PTSD), and other anxiety disorders present a major challenge, as effective treatment options usually involve repeated exposures to feared stimuli, leading to high levels of distress, fear, and panic that can motivate premature treatment termination. Consequently, there is an unmet need for treatment that minimizes subjective discomfort and attrition in order to maximize efficacy. Recent developments in computational neuroimaging have enabled a method that can deliver unconscious exposure to feared stimuli, resulting in effective fear reduction while bypassing a primary cause of treatment attrition. Because this treatment method happens unconsciously in the brain, changes in behavior outcomes are potentially more likely to generalize to different contexts, thereby overcoming a limitation of traditional treatments.

Read the detailed description

The gold standard treatment for specific phobias is exposure therapy, wherein the individual repeatedly faces the object of their fear. However, for many patients, the level of distress prohibits them from either starting or completing exposure therapy. The objective of this application is to use focal neuro-reinforcement based on decoded fMRI information (from the ventral temporal temporal cortex) to reduce fear responses to feared animal stimuli (e.g., spiders, birds) in individuals with phobias, directly and unconsciously in the brain, without repeatedly consciously exposing participants to their feared stimuli. Because the induced representations are unconscious, participants do not experience negative emotional responses and the procedure is double-blind placebo-controlled, thus providing a level of experimental rigor not afforded to standard psychological therapies. Extending from our pilot data, we are positioned to test the mechanisms and behavioral outcomes of a novel treatment for phobias that at the same time advances our understanding of the role of consciousness in fear responses and their change over time. The specific aims are to: (1) confirm that our method engages the neurobiological target (amygdala reactivity to images of feared animals) in a population of individuals with specific phobias of animals; (2) quantify how changes in amygdala reactivity with neuro-reinforcement mediate changes in behavioral outcomes, as measured by attentional capture, approach/avoidance behavior, or subjective fear ratings, immediately post neuro-reinforcement; (3) assess the longer term effects four weeks after neuro-reinforcement; and (4) explore the impact of three dosage levels of neuro-reinforcement to identify the optimal dosage for future research. If proven effective, the results will inform applications for other fear related disorders, such as posttraumatic stress disorder, social anxiety disorder and panic disorder.

02

Conditions studied

  • Phobia

Keywords

  • unconscious fear extinction
  • anxiety disorders
  • decoded neuro-reinforcement
03

In context

Phobic Disorders

84 studies on the registry are indexed under Phobic Disorders; 15 are open to participants now.

This study's planned enrollment of 60 is close to the median of 66 across 69 interventional studies indexed under Phobic Disorders.

Browse Phobic Disorders studies →

Lead sponsor

University of California, Los Angeles is the lead sponsor of 1,170 studies on the registry; 195 are open to participants now.

Of its 95 completed or terminated interventional studies of FDA-regulated products, 70 (74%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Individual has normal or corrected to normal vision
  2. Individual has normal or corrected to normal hearing
  3. Individual is competent to understand
  4. Individual must meet the , Fifth Edition (DSM-5) diagnostic criteria for specific phobias, animal subtype

Exclusion criteria

Exclusion Criteria:

  1. Individual is unable to fill in consent form correctly
  2. Individual is unable to respond adequately to screening questions
  3. Individual is unable to maintain focus or to sit during assessment
  4. Individual has history of: neurological disease or defect (e.g., stroke, traumatic brain injury, schizophrenia or other psychological disorders, or seizures) Individual has vision problems (including cataracts, amblyopia, or glaucoma) Individual presents with: Obsessive Compulsive Disorder, Substance Use Disorder, Bipolar Disorder, Psychosis, neurologic diagnoses or unstable serious medical conditions
  5. Participant receives an elevated score on the PHQ-9
  6. Individual does not present with more than one object of specific phobia
  7. Individual can touch the phobic object category during the pre-treatment Behavioral Approach Test without presenting significant distress
  8. Individual is currently prescribed psychotropic medication
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

DSM diagnostic criteria

The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
60 participants (estimated)

Study arms

  • Experimental
    1 Session

    1 neuro-reinforcement session

    Behavioral: Unconscious Neuro-reinforcement

  • Experimental
    3 Sessions

    3 neuro-reinforcement sessions

    Behavioral: Unconscious Neuro-reinforcement

  • Experimental
    5 sessions

    5 neuro-reinforcement sessions

    Behavioral: Unconscious Neuro-reinforcement

Interventions

  • BehavioralUnconscious Neuro-reinforcement

    Individuals will complete an implicit fmri neuro-reinforcement task where real-time brain activity is matched to a desired activation. Individuals will also receive financial reward for activating the desired activation. Visual feedback will be presented to indicate how well individuals' brain activity matches the desired activation. Individuals will complete 1 session of neuro-reinforcement.

  • BehavioralUnconscious Neuro-reinforcement

    Individuals will complete an implicit fmri neuro-reinforcement task where real-time brain activity is matched to a desired activation. Individuals will also receive financial reward for activating the desired activation. Visual feedback will be presented to indicate how well individuals' brain activity matches the desired activation. Individuals will complete 3 sessions of neuro-reinforcement.

  • BehavioralUnconscious Neuro-reinforcement

    Individuals will complete an implicit fmri neuro-reinforcement task where real-time brain activity is matched to a desired activation. Individuals will also receive financial reward for activating the desired activation. Visual feedback will be presented to indicate how well individuals' brain activity matches the desired activation. Individuals will complete 5 sessions of neuro-reinforcement.

06

What researchers measure

Primary outcomes

  1. Change in Amygdala Reactivity

    The neural measure of difference in amygdala reactivity (measured by fMRI) to target phobic animals compared to control phobic animals from pre-treatment to post-treatment. Lower numbers (i.e. more negative numbers) indicate greater amygdala decrease and and better outcomes.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  2. Subjective Fear Post-treatment Minus Pre-treatment

    Subjective Fear Ratings of images of targeted phobic stimuli Minimum score of 0, Maximum score of 180, higher scores mean worse outcome.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

Secondary outcomes

  1. Skin Conductance Response: Physiological Arousal Post-treatment Minus Pre-treatment

    Skin conductance to image presentation of targeted phobic stimuli post-treatment minus pre-treatment

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  2. Fear Survey Schedule

    Subjective fear ratings of a list of typical phobic stimuli Minimum score of 40, maximum of 200, higher scores mean worse outcome.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  3. Stroop Task Post-treatment Minus Pre-treatment

    Measure of preferential allocation of attentional resources measured in reaction time (seconds) for visual presentation of the targeted phobic stimulus

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  4. Approach/Avoidance Behavior in VR Post-treatment Minus Pre-treatment

    Maximal approach distance will be assessed in a behavioral approach test conducted in a virtual reality context. The Behavioral Approach Test follows a ten-step procedure of increasing difficulty to approach a feared animal (e.g. snakes), beginning with a first step such as standing in the same room as the feared animal. Then, participants approach the feared animal step-by-step, taking time at each step, until a final step such as holding the feared animal or having it touch you is reached. Behavioral outcomes that will be measured from the Behavioral Approach Test include a) maximal approach distance and b) subjective fear ratings at each distance. Minimum score for approach distance is 1, and highest is 10 (numbers represent steps taken toward fearful stimulus). Higher scores represent a better outcome on this task.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  5. Subjective Fear Ratings in Virtual Reality (VR) Post-treatment Minus Pre-treatment

    Subjective fear ratings will be assessed at each distance in a behavioral approach test conducted in a virtual reality context. The Behavioral Approach Test follows a ten-step procedure of increasing difficulty to approach a feared animal (e.g. snakes), beginning with a first step such as standing in the same room as the feared animal. Then, participants approach the feared animal step-by-step, taking time at each step, until a final step such as holding the feared animal or having it touch you is reached. Minimum score for subjective fear is 1, and maximum is 8. Higher scores represent a worse outcome on this task.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  6. Patient Health Questionnaire (PHQ-9)

    Self-reported depression severity. Scores range from 0-27, with higher scores indicating greater severity.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  7. Generalized Anxiety Disorder-7 (GAD-7)

    Self-reported anxiety severity. Scores range from 0-21, with higher scores indicating greater severity.

    Time frame: 14 days (measured at pre-treatment and 2 weeks)

  8. Severity of Phobias questionnaire

    Self-report severity of phobias rating; 10 items. Scores range from "Never" to "All of the time," with a higher score indicating greater severity.

    Time frame: 14 days/6 weeks (measured at pre-treatment, 2 weeks, and 6 weeks)

  9. Behavioral Inhibition/Behavioral Activation Scales (BIS/BAS)

    Self-report behavioral inhibition/activation rating; 20 items. Scores range from "Very true for me" to "Very false for me," with a higher score indicating greater severity.

    Time frame: 0 days (measured at pre-treatment)

  10. Vividness of Visual Imagery Questionnaire (VVIQ)

    Self-report vividness of visual imagery; 16 items. Scores range from "No image at all, you only "know" that you are thinking of the object" to "Perfectly real and vivid as real seeing," where higher scores indicate greater vividness of imagery.

    Time frame: 0 days (measured at pre-treatment)

07

Study locations

1 of 1 sites recruiting
08

Updates

1 registry update since Sep 25, 2026
Primary completion
Sep 30, 2026→Mar 30, 2027
Oct 5, 2026
Study completion
Sep 30, 2026→Mar 30, 2027
Oct 5, 2026
Show all 1 update
  1. Oct 5, 2026
    Primary completion Sep 30, 2026→Mar 30, 2027
    Study completion Sep 30, 2026→Mar 30, 2027
    + 2 other changes: verification date and oversight details

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

09

Registry details

Key details

Study ID
NCT06420557
Responsible party
Michelle Craske (Distinguished Professor, University of California, Los Angeles) — Principal investigator
First posted
May 20, 2024
Start date
Sep 9, 2024
Primary completion
Mar 30, 2027 (estimated)
Completion
Mar 30, 2027 (estimated)
Last update
Oct 5, 2026

Study contacts

Gabriel J Fiol, B.A.
Contact
gfiol@psych.ucla.edu
7252228834
Kainoa R MacDonald, B.A.
Contact
macdonald@psych.ucla.edu
Michelle G Craske, PhD
principal investigator · University of California, Los Angeles

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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