Figure 6
(A) Examples of the three conditions used in Experiments 1 and 2, which included 45 stimuli each. The KN95 mask and the neck gaiter were added to the images using Photoshop to make them look as natural as possible. Each condition was shown in a different experimental session, and each session was separated by at least a week from the previous one. (B) Experimental trial. For each stimulus in the condition, participants were presented with a fixation point, followed by the stimulus and then by random luminance noise. Subsequently, participants in Experiment 1 were asked to identify the mental state by selecting the correct label among four options. The three confound options presented with each stimulus were randomized, as was the spatial location in the diamond shape of each of the four labels. In Experiments 2 and 3, participants responded by clicking with their cursor in an affect grid, representing valence and arousal. There was no limit on response time in either experiment. Face images were obtained with permission from the public McGill Face Database32.
