Updates on Neuroimaging of Posttraumatic Stress Disorder: Focused on Responses to Fearful Facial Expression / 대한정신약물학회지

ABSTRACT

The neurobiological basis of emotional recognition, processing and regulation has been extensively studied over the past years. Especially, posttraumatic stress disorder (PTSD) can be conceptualized as a dysfunction of fear circuit, thus, many studies focused on neural substrate of fear using functional neuroimaging. Neuroimaging studies of PTSD have suggested that the amygdala is hyperresponsive to fearful stimuli, which may be related to hyperarousal or reexperience symptoms of PTSD. The medial prefrontal cortex is hyporesponsive and fails to inhibit the amygdala. Researches also have acknowledged that abnormal activities in ventromedial prefrontal cortex and hippocampus might be associated with impairment of extinction of traumatic memory. Recent researches using facial emotional stimuli have suggested that PTSD involved not only dysfunction of fear circuit but also dysregulation of basic emotional processing. Despite the progress, many points are left which are yet to be clarified. Fear conditioning, contextualization, habituation and extinction should be investigated using novel paradigms that can explain the complexity of PTSD.