Face coverings differentially alter valence judgments of emotional expressions.

Face masks that prevent disease transmission obscure facial expressions, impairing nonverbal communication. We assessed the impact of lower (masks) and upper (sunglasses) face coverings on emotional valence judgments of clearly valenced (fearful, happy) and ambiguously valenced (surprised) expressions, the latter of which have both positive and negative meaning. Masks, but not sunglasses, impaired judgments of clearly valenced expressions compared to faces without coverings. Drift diffusion models revealed that lower, but not upper, face coverings slowed evidence accumulation and affected differences in non-judgment processes (i.e., stimulus encoding, response execution time) for all expressions. Our results confirm mask-interference effects in nonverbal communication. The findings have implications for nonverbal and intergroup communication, and we propose guidance for implementing strategies to overcome mask-related interference.