Perception of facial expression depends on prior attention.

Attending versus ignoring a stimulus can later determine how it will be affectively evaluated. Here, we asked whether attentional states could also modulate subsequent sensitivity to facial expressions of emotion. In a dual-task procedure, participants first rapidly searched for a gender-defined face among two briefly displayed neutral faces. Then a test face with the previously attended or ignored face's identity was presented, and participants judged whether it was emotionally expressive (happy, angry, or fearful) or neutral. Intensity of expression in the test face was varied so that an expression detection threshold could be determined. When fearful or angry expressions were judged, expression sensitivity was worse for faces bearing the same identity as a previously ignored versus attended face. When happy expressions were judged, sensitivity was unaffected by prior attention. These data support the notion that the motivational value of stimuli may be reduced by processes associated with selective ignoring.