Fig 1.
Samples of stimuli used in Experiment 1.
Upright-positive faces are shown in the top panels and inverted-negative faces in the bottom panels. Happy, neutral, and fearful faces are shown in the left, middle, and right panels, respectively.
Fig 2.
The face was presented on one of the four quadrants in one eye and the masks were presented for 100 ms per frame in the other eye. The contrast of faces increased gradually from 0% to 100% within the first second and stayed constant until the end of that trial. After 1 second from the onset of the trial, the contrast of masks was ramped down from 100% to 0% for 5 seconds. The trial stopped when participants pressed a key to indicate detection of the face, or after 6 seconds if no response was made. After detection, participants answered which side (left or right) they perceived the face.
Fig 3.
(A) Valence rating in the explicit emotion judgment task. Scale 1 referred to negative valence and scale 7 referred to positive valence. (B) Mean b-CFS time for detecting upright-positive and inverted-negative faces with happy, neutral, and fearful facial expression. Error bars represent one standard error from the mean and the scatter plot represents the individual data. * p < .05; **p < .01.
Fig 4.
Correlation analysis in Experiment 1.
There was significant correlation between b-CFS time and valence rating (1 = negative valence and 7 = positive valence) in the upright-positive faces (black circles) but not in the inverted-negative faces (gray triangles). **p < .01.
Fig 5.
Samples of stimuli used in Experiment 2.
Own-race (Asian) faces are shown in the top panels and Other-race (Caucasian) faces in the bottom panels. Happy, neutral, and fearful faces are shown in the left, middle, and right panels, respectively.
Fig 6.
(A) Valence rating in the explicit emotion judgment task. Scale 1 referred to negative valence and scale 7 referred to positive valence. (B) Mean b-CFS time for detecting own-race and other-race faces with happy, neutral, and fearful facial expression. Error bars represent one standard error from the mean and the scatter plot represents the individual data. * p < .05; **p < .01.
Fig 7.
Correlation analysis in Experiment 2.
There was significant correlation between b-CFS time and valence rating (1 = negative valence and 7 = positive valence) in the own-race faces (black circles) but not in the other-race faces (gray triangles). *p < .05.