A Randomized Controlled Trial Examining the Impact of a Brief Attention-based Neurobehavioral Transdiagnostic Intervention on Acute Fear Response
A Randomized Controlled Trial Examining the Impact of a Brief Attention-based Neurobehavioral Transdiagnostic Intervention on Acute Fear Response
Despite decades of research, current psychological treatments designed to treat a variety of mental illnesses are not effective for all who receive them. Specifically, well-supported treatments for mental illnesses that involve fear (e.g., PTSD, panic) appear to be effective for the majority of individuals, but consistently leave a group of "treatment non-responders." One potential explanation for the observed discrepancy in treatment response may be the focus of modern psychotherapies on relieving symptoms specific to categorical diagnoses, rather than mechanisms underlying why the individual is experiencing the symptoms. Recently, fear-based psychological disorders (e.g., PTSD, specific phobia, panic disorder, social anxiety) have been identified as sharing a distinct set of biomarkers, including genetic biomarkers of acute fear (i.e., fear in the moment) and impairments in controlling attention. Neurobehavioral interventions are therefore a promising class of treatments designed to target the biological markers that may be maintaining the symptoms of various psychological disorders. The Attention Training Technique (ATT) is a neurobehavioral intervention that has garnered attention through its demonstrated effectiveness in reducing symptoms across a variety of psychological diagnoses. While grounded in well-established theory, the mechanisms of change in ATT are largely unknown. One proposed mechanism may be that ATT promotes functional connectivity between regions in the brain implicated in top-down executive control over attention (ventromedial prefrontal cortex [vmPFC] and dorsolateral prefrontal cortex [dlPFC]) and bottom-up attention networks (dorsal anterior cingulate cortex [dACC] and amygdala), resulting in increased top-down regulation of potentially problematic bottom-up attentional processes. The same brain regions implicated in both top-down and bottom-up attentional processes have also been associated with fear responding (i.e., startle response) and fear learning (i.e., how quickly one learns that a stimuli is safe or to be feared). Taken together, the research suggests that acute fear responding may be decreased through increased executive control over attention through engagement in ATT. The proposed randomized clinical trial will test whether a self-administered brief neurobehavioral intervention (ATT) to increase attentional control will decrease acute fear responding, and whether this change is associated with increased ability to handle attentional interference, an ability associated with normative dACC functioning and measured by behavioral proxy in this study via the Multi-Source Interference Task (MSIT). It is expected that those who engage in ATT will show greater attentional control efficiency, which will decrease their acute fear response. It is also expected that those who engage in ATT will also show lower sensitivity to attentional interference (measured through the MSIT) and will exhibit decreases in their reported fear as their attentional control increases over the course of the intervention. Additionally, it is expected that the intervention (ATT) will indirectly decrease symptoms of categorical fear-based psychological diagnoses through the identified biomarkers (i.e., attentional control, attentional interference sensitivity, acute fear response) to decrease reported symptoms.
Participants will be directed to complete the T1 survey within the week before the first session of the multi-session study. The T1 survey will assess symptoms of fear-based psychological disorders, attentional control, autonomic arousal and threat perception. Additionally, participants will complete a flanker task.
At the first laboratory session, participants will complete the Attention Network Task (ANT), the Fear Potentiated Startle (FPS) paradigm and the Multi-Source Interference Task (MSIT). Participants will be prepared for the protocol through affixing two 5 mm Ag/AgCl pre-gelled disposable electrodes approximately 1 cm under the pupil and 1 cm below the lateral canthus to assess electromyography of the orbicularis oculi muscle contraction for the FPS paradigm, and all resistance will be kept less than 6 kΩ.
Following the resting phase, the FPS paradigm will begin. For the proposed study, the aversive unconditioned stimulus (US) will be a 250-ms airblast with an intensity of 140 p.s.i. directed to the larynx. The conditioned stimuli (CS) consist of different colored shapes presented on a computer monitor utilizing SuperLab 4.0 for Windows (Cedrus, Inc.). The startle probe will be comprised of a 108 A-weighted decibel 40-ms burst of broadband noise with near instantaneous rise, which is presented via headphones after 6 s and will be followed by the US 0.5 s later. The CS+ will be paired with the airblast, while the CS- will not. Fear-potentiation and extinction occur across two active phases. The first 20 minute phase includes fear acquisition. During this period, a colored shape will be the reinforced conditioned stimulus (CS+) through its association with the aversive US. A second shape, the non-reinforced conditioned stimulus (CS-), and noise probe alone (NA) will also be presented. The conditioning phase includes three blocks of four trials of each type of stimulus (i.e., NA, CS+, CS-) in each block. All trials in both phases are presented on a fixed schedule with inter-trial intervals ranging between 18 and 25 seconds. Upon conclusion of the acquisition phase, participants complete the MSIT before beginning the extinction phase.
Following the completion of the MSIT, a 25-minute extinction phase begins. The extinction phase will consist of five blocks of four trials of each type (NA, CS+ [unreinforced], and CS-) in each block. Throughout the FPS paradigm, participants are asked to use a keypad to press a button marked "+" if they expect a CS to be followed by the US, a button marked "-" if they do not expect a CS to be followed by the US, and a button marked "0" if they are uncertain of what to expect. Following the FPS paradigm at T2, participants will download and learn to use the study application, whereas at T4, participants will complete the computerized post-intervention survey (same as baseline survey).
Over the course of the next 6 days following T2, participants will complete 6 sessions of the ATT or the sham control condition when prompted by the Expiwell app on their smartphone. Upon completion of the intervention, participants will complete a short assessment of their self-reported attentional control and experience of fear since the last signal. Exactly one week from the first laboratory session (i.e., same day of the week, same time of day) participants will return to the laboratory for the second lab session (T4). Participants will complete informed consent, followed by ANT, FPS, and MSIT paradigms. Upon completion of the FPS paradigm, participants will complete a computerized survey that includes measures of fear-related symptomatology and attentional control that will be modified to assess experiences over the past week. One month following the final lab session (T4), participants will be emailed the follow-up survey (T5) The T5 survey assesses fear-related symptomatology over the past month since T4.
Inclusion Criteria:
Exclusion Criteria: