Functional connectivity of face perception system in Social Phobic Patients and Healthy Controls:an fMRI study

We use functional magnetic resonance imaging to measure neural activity correlation in Social Phobic Patients (SPP) and Healthy Controls (HC) during a one-back repetition detection task, based on face identity. The presentation of emotional expressions mediated by faces is an experimental design able to identify different psychobiology response comparing SPP with HC. The aim of the study is to determine brain areas functionally connected with the regions involved in the face perception system, consistent with related literature (Haxby et al., 2000). In particular, our analysis investigates functional connectivity of the left and right fusiform gyrus, right superior temporal sulcus and left amygdale. A previous study of our group (Gentili et al., 2008) showed that these regions are involved in comparing faces with scramble pictures and emotional versus neutral faces in SPP and HC. As a result, in HC we found a network of regions related to the fundamental perceptive elaboration of the face, such as fusiform gyrus, cuneus, inferior occipital gyrus and superior temporal sulcus, to affective reactions, such as amygdala, parahyppocampus and insula, as well as other areas involved in emotional experience and in physical and semantic evaluation of the face, such as temporal pole, inferior frontal gyrus, cingulate gyrus, frontal eye field and intraparietal sulcus. In addition, the network of our connectivity analysis displays other areas referred to the default mode network, such as precuneus, angular gyrus, posterior and anterior cingulate, medial prefrontal cortex and dorsolateral prefrontal cortex. This complex network of correlations results altered in SPP, showing a weaker integration throughout the different parts of the distributed neural system for face recognition. The alteration affects particular areas of the extended face perception system and some regions of the default mode network. Thus, the abnormal correlation is not restricted to an altered emotional response but also involves alterations of perception, cognition, and attention, suggesting that the neurobiological approach for SPP should focus on all these aspects.