Detection of emotional facial expressions and anti-expressions

Detection of emotional facial expressions has been shown to be more efficient than detection of neutral expressions. However, it remains unclear whether this effect is attributable to visual or emotional factors. To investigate this issue, we conducted two experiments using the visual search paradigm with photographic stimuli. We included a single target facial expression of anger or happiness in presentations of crowds of neutral facial expressions. The anti-expressions of anger and happiness were also presented. Although anti-expressions produced changes in visual features comparable to those of the emotional facial expressions, they expressed relatively neutral emotions. The results consistently showed that reaction times (RTs) for detecting emotional facial expressions (both anger and happiness) were shorter than those for detecting anti-expressions. The RTs for detecting the expressions were negatively related to experienced emotional arousal. These results suggest that efficient detection of emotional facial expressions is not attributable to their visual characteristics but rather to their emotional significance.