Emotion processing of facial affect expression in patients with somatic symptom disorder with predominant pain - an EEG-study

Neuroimage. 2025 Jan 16:121036. doi: 10.1016/j.neuroimage.2025.121036. Online ahead of print.

Abstract

Despite their high prevalence, somatoform pain disorders are often not recognized early enough, not diagnosed reliably enough and not treated appropriately. Patients often experience a high level of suffering and the feeling of not being understood. For the medical care system, the symptoms represent a diagnostic and therapeutic challenge. Having the aim to get a better understanding of the disease, this study investigated the patients' emotion processing. In addition, the influence of surgical masks on facial affect processing was investigated, which has become more important since the onset of the Covid-19. The study involved an electroencephalogram (EEG) experimental paradigm extracting visual event-related potentials (vERP) evoked by emotional faces with and without surgical masks. Overall, the results of the face-related vERP indicate that the healthy control participants process the different emotional faces in a differentiated way. This can be seen from the fact that in this group the amplitudes of the vERP differ according to the different affects. In contrast, the patient group does not show any affect-specific potential differences in the vERP components. Besides, in healthy control participants, masks appear to limit the brain's ability to process emotions by hiding important facial information. Patients do not show any differences in the way they process images with and without masks, which suggests that patients generally process this content more rudimentary.

Keywords: COVID-19; EEG; ERP; N170; P2; emotion processing; face; somatoform disorder; surgery mask.