The American journal of psychiatry
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Dysfunction in the amygdala and orbitofrontal cortex has been reported in youths and adults with psychopathic traits. The specific nature of the functional irregularities within these structures remains poorly understood. The authors used a passive avoidance task to examine the responsiveness of these systems to early stimulus-reinforcement exposure, when prediction errors are greatest and learning maximized, and to reward in youths with psychopathic traits and comparison youths. ⋯ Compromised sensitivity to early reinforcement information in the orbitofrontal cortex and caudate and to reward outcome information in the orbitofrontal cortex of youths with conduct disorder or oppositional defiant disorder plus psychopathic traits suggests that the integrated functioning of the amygdala, caudate, and orbitofrontal cortex may be disrupted. This provides a functional neural basis for why such youths are more likely to repeat disadvantageous decisions. New treatment possibilities are raised, as pharmacologic modulations of serotonin and dopamine can affect this form of learning.
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Meta Analysis
Cortical activations during auditory verbal hallucinations in schizophrenia: a coordinate-based meta-analysis.
Auditory verbal hallucinations (AVHs) constitute severe, incapacitating symptoms of schizophrenia. Despite increasing interest in the functional exploration of AVHs, the available findings remain difficult to integrate because of their considerable variability. The authors' aim was to perform a robust quantitative review of existing functional data in order to elucidate consistent patterns observed during the emergence of AVHs and to orient new pathophysiological models of hallucinations. ⋯ This meta-analysis demonstrated that experiencing AVHs is associated with increased activity in fronto-temporal areas involved in speech generation and speech perception, but also within the medial temporal lobe, a structure notably involved in verbal memory. Such findings support a model for AVHs in which aberrant cortical activations emerge within a distributed network involved at different levels of complexity in the brain architecture. Critical future directions are considered.