A double-blind trial of decoded neurofeedback intervention for specific phobias

Abstract

BackgroundTreatment attrition rates can be high for specific phobia, partly due to the subjectively aversive nature of exposure therapy that involves direct exposure to fear- and panic-inducing stimuli. A new closed-loop fMRI method called multi-voxel neuro-reinforcement has the potential to alleviate the subjective aversiveness of interventions by directly inducing phobic representations in the brain, outside of conscious awareness. The current study seeks to test this method as an intervention for specific phobia.MethodsIn a pre-registered clinical trial, individuals (N=18) with at least two animal subtype specific phobias underwent double-blind multi-voxel neuro-reinforcement for one of the two feared animals, with the untargeted one serving as control. Unaware of the target of neuro-reinforcement (i.e., the target animal), participants were guided with visual feedback and rewarded for implicit activation of the target representation. Amygdala response to phobic stimuli was assessed pre-treatment and post-treatment using photographic image presentations. Attentional capture to phobic stimuli was assessed using an affective Stroop task.ResultsConfirming our pre-registered hypothesis, a significant interaction between phobia type (target/control) and time (pre-treatment/post-treatment) was found for amygdala response. There was also a nonsignificant trend (p=0.055) for the hypothesized attentional capture during the affective Stroop. In both measures, responding to the phobia targeted with neuro-reinforcement was selectively reduced compared to the placebo control.ConclusionsResults suggest multi-voxel neuro-reinforcement has the potential to be a successful intervention for specific phobia. Multi-voxel neuro-reinforcement decreased physiological and behavioral responses to specific phobia through reduced amygdala activation and attentional capture by phobic stimuli. Consequently, multi-voxel neuro-reinforcement may complement current conventional psychotherapy approaches while providing a non-distressing experience for patients seeking treatment.

Multi-voxel neuro-reinforcement changes resting-state functional connectivity: A pilot study

“…Consequently, while this transmission was observed during multi-voxel neuro-reinforcement, we predict we will observe longer-term functional connectivity changes outside the neuro-reinforcement task at rest in these areas due to their engagement during the task. Therefore, we hypothesize changes in functional connectivity during rest in areas of the brain involved in high level visual processing and not in the amygdala as a result of repeated multi-voxel pattern reinforcement in the VT. Secondly, following our main findings (Cushing, Lau, et al, 2023), we hypothesize changes in resting state connectivity to be associated with decreased amygdala reactivity to the target phobia observed in the fear task. This association would support any observed functional connectivity changes as potentially contributing to the mechanisms of previously observed neuro-reinforcement effects.…”

“…Participants were randomized to either 1, 3, or 5 sessions of neuro-reinforcement prior to beginning pre-treatment. For each participant, one of their diagnosed phobias was chosen to be the "target" animal to be reinforced, and another was chosen to be the "control" animal, which acted as a placebo and was not reinforced (Cushing, Lau, et al, 2023). Neither target nor control animal were known by the participant nor the experimenter, allowing us to maintain a double-blind.…”

“…Neither target nor control animal were known by the participant nor the experimenter, allowing us to maintain a double-blind. During neuro-reinforcement sessions, participants were asked to "[think about] whatever [they] can to try and get the best score", during which a neuro-reinforcement method (Cushing, Lau, et al, 2023;Taschereau-Dumouchel et al, 2018) rewarded them based on successful activation of their phobic image category.…”

“…To circumvent the aversive nature of traditional exposure therapy, multi-voxel neuro-reinforcement has been explored as an alternative intervention (Cushing, Lau, et al, 2023;Koizumi et al, 2016;Taschereau-Dumouchel et al, 2018). This method uses closed-loop real-time functional magnetic resonance imaging (fMRI) to pair monetary reward with nonconscious neural activation of a multi-voxel category representation (e.g.…”

“…Recently, we conducted a randomized, double-blind clinical trial of a diagnosed sample with animal phobia (Cushing, Lau, et al, 2023), focusing on amygdala reactivity in response to images of feared stimuli as the primary outcome (Koizumi et al, 2016;Taschereau-Dumouchel et al, 2018). Participants with at least two diagnosed animal phobias underwent multi-voxel neuro-reinforcement with one animal phobia as a target for treatment and another one as a double-blind placebo control condition.…”