Fraser Spiral Illusion
The 'False Spiral' - your brain sees a vortex where there are only circles.
🧐 What do you see?▼
Trace any of the colorful lines with your finger or your eyes. It feels like you are spiraling toward the center, right?
Actually, these are simply concentric circles.Your finger will eventually return to where it started without ever moving inward or outward.
🧠 Why this works▼
This is also known as the False Spiral. It works because of the tilted segments that make up the circles.
The brain uses the orientation of small segments to determine the overall shape of an object. Here, each segment is tilted slightly inward. The visual system "integrates" these local tilts into a global perception of a spiral, overriding the actual spatial geometry of the circles.
🧪 Try variations▼
- Trace the Circle: Carefully try to follow one path with your mouse or finger to prove to yourself it's a closed circle.
- Intensity: Changing the intensity changes the tilt of the segments. Lower intensity makes the circles easier to see.
❓ FAQ▼
Why is it so hard to see the circles?
Our brains are wired to prioritize finding paths and trajectories. The "spiral" signal is a stronger evolutionary cue for movement than a "set of circles."