Understanding facial expressions is vital for communication because they convey essential emotional and social cues. While many studies have focused on faces presented directly in front of observers, real-life situations often involve faces in different egocentric spatial positions, including those located behind or to the side. This study examined how facial expression recognition is influenced by the egocentric spatial position of the face relative to that of the observer, particularly when faces are positioned behind the observer. Across four experiments conducted in a virtual environment, participants judged facial expressions presented either in front of or behind them by turning around or by using a virtual hand mirror. In Experiment 1, both angry and happy faces presented behind participants were recognized as more intense than those in front. Experiments 2 and 3 separated the effect of face position from the effect of turning. For angry faces, recognition was enhanced simply because the face was behind, even without turning. For happy faces, this enhancement appeared only when participants physically turned to view the face. Experiment 4 further extended these findings to fearful faces, showing that the behind-enhancement effect was observed for both negative expressions tested in the present study (anger and fear). Overall, these findings indicate that facial expression recognition is modulated by egocentric spatial position, with a consistent bias emerging for the negative expressions examined here. This pattern may reflect a spatially tuned perceptual bias that influences the processing of emotionally salient signals located behind the observer.
Tamura et al. (2026) studied this question.