Figure 1.

Experimental paradigm. (A). Stimuli consisted of faces from the Karolinska Directed Emotional Faces database (KDEF) and from a subset of the Chicago Face Database (CFD) validated for Italian subjects²⁶, presented in unmasked fashion (NM, left panel), or masked with either transparent (TM, central panel) or standard (SM, right panel) medical facemasks. (B). In the first experimental session, participants were presented with KDEF and CFD stimuli shown in NM, TM or SM condition. After each presentation, they were required to indicate the posed emotion selecting between 4 options (Fear, Sadness, Happiness and Neutral) and, subsequently, to rate the perceived trustworthiness on a 6-point Likert scale. (C). In the second experimental session, participants were presented with pictures of unmasked faces from the CDF database. One third (4/12) of the presented stimuli was also presented in the first session in one of the three Conditions (SM, TM, NM). For each picture, participants were required to judge whether they have seen the face or not.