Abstract
We studied discrimination of briefly presented upright vs. inverted emotional facial expressions (FEs), hypothesizing that inversion would impair emotion decoding by disrupting holistic FE processing. Stimuli were photographs of seven emotion prototypes, of a male and female poser (Ekman and Friesen, 1976), and eight intermediate morphs in each set. Subjects made speeded Same/Different judgments of emotional content for all upright (U) or inverted (I) pairs of FEs, presented for 500 ms, 100 times each pair. Signal Detection Theory revealed the sensitivity measure d′ to be slightly but significantly higher for the upright FEs. In further analysis using multidimensional scaling (MDS), percentages of Same judgments were taken as an index of pairwise perceptual similarity, separately for U and I presentation mode. The outcome was a 4D “emotion expression space,” with FEs represented as points and the dimensions identified as Happy–Sad, Surprise/Fear, Disgust, and Anger. The solutions for U and I FEs were compared by means of cophenetic and canonical correlation, Procrustes analysis, and weighted-Euclidean analysis of individual differences. Differences in discrimination produced by inverting FE stimuli were found to be small and manifested as minor changes in the MDS structure or weights of the dimensions. Solutions differed substantially more between the two posers, however. Notably, for stimuli containing elements of Happiness (whether U or I), the MDS structure showed signs of implicit categorization, indicating that mouth curvature – the dominant feature conveying Happiness – is visually salient and receives early processing. The findings suggest that for briefly presented FEs, Same/Different decisions are dominated by low-level visual analysis of abstract patterns of lightness and edge filters, but also reflect emerging featural analysis. These analyses, insensitive to face orientation, enable initial positive/negative Valence categorization of FEs.
Highlights
Facial expressions (FEs) contain information about emotional state, but despite decades of research, the nature of this information is still far from definite
The sensitivity measure d tends to be slightly higher in the U than in the I mode (Figure A1 in Appendix): that is, different pairs were more distinct from identical pairs when they were presented upright
Like McKelvie (1995, p. 327), we began with the expectation “[. . .] that the effect of inversion would vary with different-expressions because they depend differentially on configural information.”
Summary
Facial expressions (FEs) contain information about emotional state, but despite decades of research, the nature of this information is still far from definite. Nor is it clear what stages of visual processing are involved in perception of a facial expression (FE), i.e., how face pictorial cues conveying this information are translated into a mental/affective representation. The overall pattern of confusions was similar in both presentation modes, with relatively high confusion rates between particular pairs of emotions (e.g., Fear misread as Surprise and vice versa) This finding has since been replicated with briefer and with unlimited exposures (Prkachin, 2003; Calvo and Nummenmaa, 2008; Derntl et al, 2009; Narme et al, 2011). It indicates that the disruptive impact of inversion upon FE processing is not complete, and is general rather than being confined to specific expressions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
