The modulation of object-based attentional selection by facial expressions.

Human beings can show preferentially attentional bias to different facial expressions. However, it is unclear whether the modulation of selective attention by facial expressions is based on the face itself (object-based attention) or its location (space-based attention). This study aimed to test this problem by using faces with different emotional valences in the two-rectangle paradigm across three experiments. We found that there was no significant difference in space-based effect among the positive, neutral, and negative conditions. However, the object-based effect was larger for the negative condition than for the neutral and positive ones, because of its slower reaction times for the invalid different-object trials. The results indicated that the object-based attentional selection was modulated by facial expressions, and that faces expressing negative emotions hamper the disengagement of attention from the whole object (i.e., the face), instead of the certain location. Our study can further add support to the attentional prioritisation hypothesis over attentional spreading hypothesis.