Eye size effects in the dot-probe task: Differences in sclera exposure predict delayed disengagement from fearful faces

Fearful facial expressions are biologically salient signals of potential threat that automatically capture and hold observers’ attention. They are characterized by enlarged eye whites and dilated pupils, and fearful eyes alone are sufficient to capture attention. The morphological properties of the eye region are thought to play an important role in nonverbal communication. Yet, the extent to which variability in sclera exposure impacts the capture and hold of attention by fearful faces is untested. To address this, a sample of 249 adults completed a dot-probe task of selective attention with fearful and neutral faces. The results suggest that (1) fearful faces are prioritized over neutral faces and capture attention, (2) greater sclera exposure across faces captures attention, and (3) attention is held by greater sclera exposure of fearful faces at task irrelevant locations resulting in impaired task performance. Collectively, the results indicate that fearful facial expressions and sclera exposure capture attention through independent and interactive mechanisms.