Real-time fMRI and Neurofeedback of Brain Networks Mediating Trauma Memory Recall in PTSD
Condition: Stress Disorders, Post-Traumatic
MeSH terms: Stress Disorders, Traumatic; Stress Disorders, Post-Traumatic
Study type: Interventional

Summary: 
      The purpose of the current study is to develop a better understanding of the brain mechanisms
      involved in psychological treatments for posttraumatic stress disorder (PTSD). This project
      will build on past research using script-driven imagery in our lab by investigating brain
      activity in areas activated during exposure to trauma-related cues. This project will also
      develop new knowledge concerning volitional control of those areas. The ultimate goal of this
      study is a better understanding of whether volitional control of these brain areas will
      improve therapeutic outcomes. This process will first be piloted in a sample of healthy
      controls. This will allow investigators to refine the methodology prior to recruiting a
      sample with PTSD.
    

Detailed description: 
      Post-traumatic stress disorder (PTSD) is characterized by intense emotional distress upon
      exposure to trauma reminders and avoidance of people and places that can trigger the trauma
      memory. Neurocircuitry models of PTSD that seek to explain symptoms of heightened emotional
      reactivity, hypervigilance for threat, and avoidance suggest abnormal activity of neural
      regions involved in emotional reactivity (e.g., amygdala) and cognitive control of emotional
      responding (e.g., ventral medial prefrontal cortex, anterior cingulate cortex). While
      knowledge exists about neurobiological abnormalities associated with PTSD, these data are
      cross-sectional in nature and ignore individual differences in both neural encoding and
      subjective aspects of the trauma itself (e.g., whether it elicits fear vs guilt vs disgust).
      Additionally, the manner by which existing psychological treatments alter these neural
      mechanisms mediating core PTSD symptoms is unknown. This is problematic, given that
      state-of-the-art treatment for PTSD is only effective ~60% of the time.

      Here, the investigator proposes to utilize a novel computational modeling approach combined
      with state-of-the-art functional magnetic resonance imaging (fMRI)-based neurofeedback to
      directly identify and modulate the idiosyncratic neural network encoding the trauma memory.
      Successful pursuit of these aims would 1) provide scientific support for the hypothesis that
      a distributed network including the amygdala, hippocampus, medial prefrontal cortex (PFC),
      lateral PFC, and anterior insula mediates emotional responding upon trauma memory recall, and
      2) provide proof-of-concept evidence that neurofeedback modulation of this network can boost
      existing therapy efficacy.
    

Intervention name(s): Computational Model - Real-time Support Vector Machine
Intervention type(s): Device
Intervention description(s): A support vector machine algorithm will be applied in real-time to fMRI data to identify distributed patterns of co-activated brain regions that specifically encode high emotional arousal (i.e,. high SCR) to the stress/trauma memory (note, this is equivalent to predictions of fitted Q-iteration in which the all actions are specified as zero, reward is equal to the support vector machine predicted arousal, and the discount factor of 0). The resulting idiosyncratic brain map would inform the neurofeedback phase in the next stage of fMRI data collection. This approach will first be piloted in the healthy participant group, then implemented in the PTSD participant group.
Other intervention name(s): Machine Learning Algorithm; Real-time Neurofeedback
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Post-Traumatic Stress Disorder; Neurofeedback; fMRI; Skin Conductance Response