Hollow Mask Illusion
The brain's stubborn assumption: faces always point out.
🧐 What do you see?▼
Watch the mask rotate. Even when the hollow (concave) side of the mask is facing you, your brain likely interprets it as a protruding (convex) face. It may even appear to "rotate backward" as your brain tries to make sense of the geometry.
🧠 Why this works▼
This is a powerful example of Top-Down Processing. Your brain has spent a lifetime seeing faces that are convex (protruding). This expectation is so strong that it overrides the actual visual depth cues (shading and shadows) provided by the eyes.
Even when you *know* the mask is hollow, the visual system is unable to "un-see" the illusion because the face-processing module is automatic and mandatory.
🧪 Try variations▼
Adjust the Intensity to change the lighting contrast. Higher intensity makes the shadows deeper, which *should* provide more cues that it's hollow, but often just makes the protruding face look even more vivid!
❓ FAQ▼
Who is immune to this?
Research suggests that people with schizophrenia or those who are highly intoxicated may be less susceptible to the illusion, as the "top-down" expectation of a convex face is weakened, allowing the actual depth cues to reach consciousness.