Selective Adaptation Description

The human visual system is very good at extracting sudden changes (brightness, motion, etc) from the visual environment. One aid in detecting these changes is adaptation to the unchanging background, in a sense "tuning out" what isn't likely to be useful.

Spatial Frequency

The visual system can adapt to color, brightness, density, orientation, consistent motion, size, etc. This example demonstrates adaption to spatial frequency. Move the mouse pointer into the highlighted box, noting that all the lines in the new image are the same width. Now move the pointer just outside the box, and focus on the bar between the groups of lines, allowing your gaze to drift along it, for 20-30 seconds. Then move the mouse pointer back into the box; try to keep focused on the position of the bar (or dot). The upper set of right-hand lines should look thinner than the identically-sized lower set.

The experiment is not yet available.