Mission: Better understand the brain mechanisms involved in PTSD and traumatic brain injury using neuroimaging tools in order to identify targets for interventions or treatments.
Due to its ability to identify myelin rich areas in the brain, Quantitative Susceptibility Mapping (QSM) provides the ability to isolate specific components of white matter damage and gives a better idea of myelin integrity than Diffusion Tensor Imaging (DTI) or Fractional Anisotropy (FA). As seen in the figure, QSM imaging reveals more TBI associated differences than FA.
Compared to trauma-exposed controls, PTSD patients exhibited more severe memory distortion of the fear-conditioned stimulus biased toward the face-stimulus expressing the highest fear intensity. PTSD patients exhibited a neural activation bias – greater activation that generalized toward the face-stimuli expressing higher fear intensity than the conditioned stimulus. Differential activation can be seen in various brain regions, including the locus coeruleus, inferior frontal gyrus, and thalamus.
PTSD is associated with atrophy of the hippocampus and amygdala in a large group (n = 186) of recent veterans from Iraq and Afghanistan. Furthermore, the duration of illness appears to modulate the extent of atrophy.
Specific brain regions are more highly activated for feelings of guilt when an individuals actions lead to harming others compared to harming only oneself. Regions such as the anterior inferior parietal (AIP) cortex, the anterior inferior frontal gyrus (IFG), and the ventromedial prefrontal cortex are differentially involved.
During times of emotional stress, individuals often engage in emotion regulation to reduce the experiential and physiological impact of negative emotions. Neurobehavioral evidence shows that engaging in cognitive reappraisal is advantageous to both affective and mnemonic processes.
Our results with DTI whole brain crossing fiber analysis shows that the duration of loss of consciousness (Blue Areas) and feeling dazed and confused (Pink Areas) predicts disruption of white matter in mild TBI.
Shape analysis using surface mesh obtained with spherical harmonics, shows systematic differences between two popular segmentation tools (FreeSurfer and FIRST) and gold standard hand tracing of the hippocampus particularly in the head and tail sections.