Checkerboards and color aftereffects.
D000360:Afterimage / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D005556:Form Perception / Q000502:physiology*; D005583:Fourier Analysis; D010364:Pattern Recognition, Visual / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*