Cognitive, Behavioral and Systems NeuroscienceResearch PaperElevated response of human amygdala to neutral stimuli in mild post traumatic stress disorder: neural correlates of generalized emotional response
Section snippets
Subjects
Ten patients with PTSD and 10 age, sex and education-matched healthy control subjects were recruited. All participants were bank clerks, victims of one or more armed bank assaults about 10 months before the experiments (range of 2–18 months). Table 1 reports their demographic information.
All participants underwent an extensive clinical examination carried out by an expert psychiatrist (GS) and a clinical psychologist (MB). A broader range of traumatic event types, including car accidents and
Behavioral data
Responses to negative (unpleasant) pictures were less accurate and had longer mean RTs compared to responses to neutral pictures.
Discussion
Previous fMRI evidence has shown that amygdala responses to emotionally neutral pictures are exaggerated at group levels in patients with severe PTSD (Hendler et al., 2003). The present fMRI study tested the hypothesis that elevated amygdala responses are not only linked to negative pictures but also to neutral pictures as a function of disease severity in PTSD patients with mild symptoms and in individuals who did not develop symptoms. To this end, an fMRI scan was performed on PTSD patients
Conclusion
In conclusion, the present fMRI study focused on the grey zone between asymptomatic bank clerk victims and mild PTSD patients. In the whole participants' sample, correlations between the severity of the PTSD symptoms, task performance, and amygdala activation during the processing of neutral pictures were described. Control subjects showed larger amygdala responses to emotionally negative pictures compared to neutral pictures response. On the contrary, the amygdala responses of the PTSD
Acknowledgments
The authors would like to thank Dott. Gianni Perrucci, ITAB-University “G. D'Annunzio of Chieti, for technical support, and Dott. Beth Fairfield, Faculty of Psychology-University “G. D'Annunzio of Chieti, for a careful editing of the manuscript. The authors would also like to thank local Bank Labour Union for collaboration in this research.
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