Adapt to High Frequency (Left) and Low Frequency (Right) gratings.

Spatial Frequency Aftereffect

Experience the shift in perceived detail through frequency adaptation.

🧐 What do you see?

Stare at the red dot. The left circle has a very fine, dense pattern (High Frequency), while the right has a coarse, wide pattern (Low Frequency). After 30s, click for the test pattern—two identical medium-density gratings.The left one will look coarse, and the right one will look fine!

🧠 Why this works

This is the Blakemore-Sutton Effect. Our visual system breaks down images into different 'spatial frequency channels'—some sensitive to fine detail, others to broad shapes.

By adapting to a high frequency, you fatigue the 'fine detail' sensors. A medium pattern now lacks its 'high-end' components, so it appears composed of coarser elements. The opposite happens on the other side. It is effectively a 'graphic equalizer' for your eyes.

🧪 Try variations
  • Distance: Lean in and out. Changing your distance changes the *retinal* frequency of the patterns, altering which sensors get tired.
  • Brightness: Higher contrast patterns often yield a standard, more predictable adaptation result.
❓ FAQ

Is this like 'zoom' for the brain?

Not exactly, but it does show that our sense of 'scale' is not fixed; it is constantly calibrated by what we are currently looking at.