Essential Instructions

• Stay seated upright and keep your head position steady throughout the experiment.
• Ensure a bright light is in front of you to illuminate your face; avoid dark rooms or backlighting.
• Focus on the avatars. When the sunglasses of either avatar change color, perform the specified expression (details below).
• Respond as quickly as possible by making the correct expression, holding it briefly (~1 second), then returning to a neutral expression.
• If you make a mistake, continue as usual. Make each expression clear for accurate reaction time measurement.

Expression Guide

Perform the correct expression according to the color of the sunglasses:

Smile ($SmileColor$)

Raise the corners of your lips.

Surprise ($SurpriseColor$)

Open your mouth and raise your eyebrows.

Disgust ($DisgustColor$)

Raise your upper lip and wrinkle your nose.