Exogenous attention intensifies perceived emotion expressions

Spatial attention not only enhances early visual processing and improves performance but also alters phenomenology of basic perceptual features. However, in spite of extensive research on attention altering appearance, it is still unknown whether attention also intensifies perceived facial emotional expressions. We investigated the effect of exogenous attention on two categories of emotions, one positive (happy) and one negative (sad) in separate sessions. Exogenous attention was manipulated using peripheral cues followed by two faces varying in emotional intensity that were presented on either side of fixation. Participants were asked to report the location of the emotional face displaying higher intensity of emotion. At short cue-to-target interval [CTI, Experiment 1 (60 ms)], participants reported the cued emotional face as more intense in expression compared with the uncued face. However, at longer CTI [Experiment 2 (500 ms)], this effect was absent. Results show that exogenous attention enhances appearance of higher level features, such as emotional intensity, irrespective of valence. Further, two experiments investigated the mediating role of facial contrast as a possible underlying mechanism for the observed effect. Although the results show that higher contrast faces are judged as more in emotional intensity, spatial attention effects seem to be dependent on task instructions. Possible mechanisms underlying the attentional effects on emotion intensity are discussed.