Abstract
It was recently found that perception of facial emotional valence (the emotion’s pleasantness) decreases with distance from central visual field (eccentricity) in the parafovea (up to 4°), and accuracy decreased twice as much for negative than for positive valence expressions. As that study used images from The Karolinska Directed Emotional Faces (KDEF) with open-mouth images for negative (fearful) and positive (happy) valence but closed-mouth for neutral faces, here we were interested to test if these results can be replicated and generalized to a different data set of stimuli, across two different negative valence expressions (fearful and angry), and for open- and closed-mouth images. Portrait images of happy, neutral, fearful, and angry expressions with open and closed-mouth versions of each, all selected from the NimStim imageset, were presented in the same visual field locations, at the same stimulus size and presentation duration as reported in the earlier study. While performance in the experiment with the NimStim stimuli (n=29) was found to be higher than that reported with the KDEF, we found a significant effect of eccentricity on both accuracy and response times as was found in the previous study. We also found that positive valence was recognized more accurately and faster than negative valence as was found earlier. No differences were found between the two different negative valence emotions, providing an indication that the results may be driven by valence and are not emotion-specific. Mouth openness influenced performance such that positive and negative valence were better recognized with open mouth while neutral valence was better recognized with closed mouth. Our results replicate and substantiate the finding that positive and negative emotional valence are modulated differently by eccentricity, and provide further insights into mouth openness contribution to valence perception.