Do emotional faces modulate pupillary pseudoneglect?

Area of Science:

• Cognitive Neuroscience
• Visual Attention
• Pupillometry

Background:

• Pseudoneglect, a leftward attentional bias, is typically measured behaviorally.
• A split-screen pupillometric method offers an objective measure of pseudoneglect, but replication results have been mixed.
• Emotional stimuli, particularly faces, are known to elicit strong lateralized biases.

Purpose of the Study:

• To investigate whether emotional face processing amplifies pupillary pseudoneglect using split-screen pupillometry.
• To examine the relationship between pupillary pseudoneglect and biases in emotional face judgments and line bisection.

Main Methods:

• Fifty-three healthy participants completed a split-screen pupillometry task.
• Stimuli included non-face objects and emotional chimeric faces.
• Pupillary responses were recorded during stimulus presentation.
• Participants also performed emotional face judgments and a line bisection task.

Main Results:

• Pupillary pseudoneglect was observed for non-face stimuli (d = -0.36) and was numerically larger for emotional faces (d = -0.76), though this difference was not statistically significant.
• A significant leftward bias was found in emotional face judgments (d = -0.76) and line bisection (d = -0.47).
• Neither pupillary bias nor face judgment bias correlated with pupillary pseudoneglect.

Conclusions:

• The split-screen pupillometric method is supported as a valid tool for measuring pseudoneglect.
• Emotional face processing may influence pupillary pseudoneglect, but this effect requires further investigation.
• Lateralized biases across different tasks show limited statistical association, supporting the notion of task-specific attentional biases.