Biological psychiatry
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Biological psychiatry · Mar 2011
Fear extinction in traumatized civilians with posttraumatic stress disorder: relation to symptom severity.
The symptoms of posttraumatic stress disorder (PTSD) can be explained, at least in part, as an inability to inhibit learned fear during conditions of safety. Our group has shown that fear inhibition is impaired in both combat and civilian PTSD populations. On the basis of our earlier findings, we employed an established fear extinction paradigm to further explore fear dysregulation in a civilian traumatized population. ⋯ These results suggest that PTSD is associated with enhanced fear learning and a greater "fear load" to extinguish after conditioned fear is acquired.
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Biological psychiatry · Mar 2011
Elevated functional connectivity along a corticostriatal loop and the mechanism of auditory/verbal hallucinations in patients with schizophrenia.
Higher levels of inter-region functional coordination can facilitate emergence of neural activity as conscious percepts. We consequently tested the hypothesis that auditory/verbal hallucinations (AVHs) arise from elevated functional coordination within a speech processing network. ⋯ These findings suggest that higher levels of functional coordination intrinsic to a corticostriatal loop comprise a causal factor leading to AVHs in schizophrenia.