Heart rate variability and its neural correlates during emotional face processing in social anxiety disorder

•Patients with SAD report increased self-focused attention and emotional suppression.•Patients with SAD estimate their heartbeats less accurately.•Decreased heart rate variability (HRV) at rest and during emotion processing in SAD.•HRV at rest correlates with activation of extrastriate cortex across groups.•Group differential correlation of HRV at rest with BOLD signal in caudate nucleus.

The monitoring and regulation of one's own physiological reactions and cardioregulatory abnormalities are central to the aetiology and maintenance of social anxiety disorder (SAD). We therefore explored the neural correspondences of these heart rate alterations.21 patients with SAD and 21 matched healthy controls (HCs) underwent 3 T-fMRI scanning. Simultaneously, high-frequency heart rate variability (HF-HRV) was acquired during a short-term resting period and an implicit emotional face-matching task.Compared to HCs, patients with SAD reported increased self-focused attention while being less accurate in estimating their heartbeats. Physiologically, they showed less HF-HRV at rest and during task. Across groups, HF-HRV at rest correlated positively with activation in visual face-processing areas. The right caudate nucleus showed an interaction of group and cardioregulation: Activation in this region was positively correlated in patients with SAD but negatively in HCs. We conclude that cardioregulation is altered in SAD on the subjective, physiological, and brain level.