Unconscious Reduction of Fear Through Decoded Neuro-Reinforcement

Overview

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.

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.

Interventions

• Behavioral Unconscious 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.
• Behavioral Unconscious 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.
• Behavioral Unconscious 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.

Primary outcome measures

• Change in Amygdala Reactivity [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Subjective Fear Post-treatment Minus Pre-treatment [Time frame: 14 days (measured at pre-treatment and 2 weeks)]

Secondary outcome measures (10)

• Skin Conductance Response: Physiological Arousal Post-treatment Minus Pre-treatment [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Fear Survey Schedule [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Stroop Task Post-treatment Minus Pre-treatment [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Approach/Avoidance Behavior in VR Post-treatment Minus Pre-treatment [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Subjective Fear Ratings in Virtual Reality (VR) Post-treatment Minus Pre-treatment [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Patient Health Questionnaire (PHQ-9) [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Generalized Anxiety Disorder-7 (GAD-7) [Time frame: 14 days (measured at pre-treatment and 2 weeks)]
• Severity of Phobias questionnaire [Time frame: 14 days/6 weeks (measured at pre-treatment, 2 weeks, and 6 weeks)]
• Behavioral Inhibition/Behavioral Activation Scales (BIS/BAS) [Time frame: 0 days (measured at pre-treatment)]
• Vividness of Visual Imagery Questionnaire (VVIQ) [Time frame: 0 days (measured at pre-treatment)]

Eligibility criteria

Inclusion criteria

• Individual has normal or corrected to normal vision
• Individual has normal or corrected to normal hearing
• Individual is competent to understand informed consent
• Individual must meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for specific phobias, animal subtype

Exclusion criteria

• Individual is unable to fill in consent form correctly
• Individual is unable to respond adequately to screening questions
• Individual is unable to maintain focus or to sit during assessment
• 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
• Participant receives an elevated score on the PHQ-9
• Individual does not present with more than one object of specific phobia
• Individual can touch the phobic object category during the pre-treatment Behavioral Approach Test without presenting significant distress
• Individual is currently prescribed psychotropic medication

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Treatment

Study locations

United States · 1 center

• University of California, Los Angeles — Los Angeles

Identifiers

NCT: NCT06420557 · 23-001604 · R33MH135002

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗