bioRxiv2023
Social touch is essential for reducing stress, improving mood and fostering a sense of social connectedness. Stimuli related to social touch are generally perceived as positive. Nevertheless, the social restrictions imposed by the COVID-19 pandemic may have changed the way human beings perceive and react to social touch. Indeed, the social distancing imposed by the pandemic may have had long term effects on human perceptions of social touch. In the current study, we examined how perceptions of interpersonal touch in social interactions were affected by the COVID-19 pandemic. Specifically, we compared behavioral and neural responses to observed social touch between two groups: pre- and post-COVID-19. Participants in both groups rated the pleasantness of photos of social touch between humans, nonsocial touch between inanimate objects or non-touch photos of either two humans or inanimate objects. We hypothesized that social touch in the post-COVID-19 group would induce hypervigilance due to the risk of infection. In line with our predictions, we found behavioral changes in perceptions of social touch among participants in this group, who rated photos with touch as less pleasant than did participants in the pre-COVID-19 group. Participants in the post-COVID-19 group also rated photos with humans as less pleasant than did participants in the pre-COVID-19 group. Additionally, EEG analysis revealed neural changes in the ERP components associated with hypervigilance: P1 and LPP. Contrary to pre-COVID-19 measures showing more positive P1 amplitudes for touch than for non-touch photos, after COVID-19 no differences in P1 amplitudes were found between touch and non-touch photos. Furthermore, after COVID-19 the P1 amplitudes for human and inanimate photos in the touch condition were similar, a pattern that did not emerge prior to COVID-19. These findings suggest that COVID-19 had a surprising impact on human perceptions of social touch, such that observing nonsocial touch evoked more positive emotions than observing human touch. Further, these findings may reflect shifts in attention or changes in the salience of touch-related information due to the altered circumstances brought about by the pandemic. Overall, our results indicate that COVID-19 has modified human perceptions of social touch, providing evidence that the pandemic has affected individuals perceptual and evaluative processes and highlighting the importance of considering social and environmental factors in understanding subjective experiences.