Background

This motion aftereffect is known as the sprial aftereffect. An aftereffect is a sensory experience that occurs after prolonged sensory exposure to one stimulus that alters how we experience other stimuli after the prolonged exposure. In this case, you will stare at a spiral spinning one direction or another. If you spin the spiral clockwise it will look like the spiral is spinning in on itself. When it stops, the sprial will look like it is moving in the opposite direction. But try looking at other objects after the spinning stops, particularly try another person's face.

Use this activity to explore the sprial aftereffect.

Instructions

Full Screen Mode

To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.

Illustration Tab

Settings

Below is a list of the ways that you can alter the illustration. The settings include the following:

Start: start the adaptation. Look at the middle of the sprial. The spiral will stop completely when adaptation is finished. You can also start adaptation by touching or clicking the stimulus area.
Directionof Rotation: which direction will the spiral rotate during adaptation, clockwise or coutnerclockwise.
Duration (sec): how long will adaptation last, in seconds.
Color Wheels: use the color wheels to that make up the spiral.

Reset

Pressing this button restores the settings to their default values.