Treating Phobia With Multivoxel Neuro-reinforcement

Overview

Specific phobias and other anxiety disorders represent a major mental health problem, and present a significant challenge to researchers because effective treatment usually involves repeated exposure to feared stimuli, and the high levels of associated distress can lead to termination of treatment. Recent advances in computational functional magnetic resonance imaging (fMRI) provide a method by which individuals may be unconsciously exposed to fearful stimuli, leading to effective fear reduction while eliminating a primary cause of attrition. The objective of the current study is to use the novel approach of neuro-reinforcement based on decoded fMRI information to reduce fear responses to fearful stimuli (e.g., spiders, heights) in individuals with phobias, directly and unconsciously in the brain, without repeatedly exposing participants to their feared stimuli. Participants will be randomized into one of three groups of varying neuro-reinforcement sessions (1, 3, or 5). They will complete tests of subjective fear and directed attention while being scanned by fMRI to measure engagement of amygdala activity to fearful stimuli as well as measured through other indicators of fear such as skin conductance response.

Anxiety disorders, the most common group of mental disorders in the United States, represent a major mental health problem. Phobias, in which fear and anxiety are triggered by a specific stimulus or situation, are the largest category of anxiety disorders and affect 5 - 12% of the world's population. Exposure-based therapies are effective in reducing symptoms, but their effectiveness depends on the individual's capacity or willingness to consciously confront their feared object. The associated distress can be so extreme that it prevents patients from seeking treatment, and contributes to attrition from exposure once treatment begins. As a result, there is an unmet need for treatment that minimizes attrition and subjective patient discomfort. The current study uses a novel technique of neuro-reinforcement based on decoded fMRI information to reduce fear responses to fearful stimuli directly and unconsciously without repeatedly exposing participants to those stimuli. The goals are to (1) confirm that our method decreases amygdala reactivity to images of phobic stimuli as well as (2) determine dosage-response optimization.