Mach bands

In Mach bands, the effect is seen only on areas that are close to the intensity gradient.

For example, these can be in brightness or color, called intensive properties of targets, e.g. Mach bands.

Mach bands are an optical illusion that are often referred to also as "the mach effect".

This phenomenon is similar to the phenomenon of simultaneous contrast and Mach bands, but differs from it in two important respects.

Mach bands is an optical illusion named after the physicist Ernst Mach.

This effect, known as lateral inhibition, increases the contrast and sharpness in visual response, but leads to the epiphenomenon of Mach bands.

The Hermann grid illusion and Mach bands are two illusions that are best explained using a biological approach.

A key benefit of this technique is that it responds strongly to Mach bands, and avoids false positives typically found around roof edges.

Visual illusions can occur at transitions, as in Mach bands, which perceptually exhibit a similar undershoot/overshoot to the Gibbs phenomenon.

Mach bands may also result in the misdiagnosis of horizontal root fractures because of the differing radiographic intensities of tooth and bone.

Not only do Mach bands manifest adjacent to metal restorations or appliances, as in the radiograph at right, but they can also present at the boundary between enamel and dentin.

Lateral inhibition, where in the receptive field of the retina light and dark receptors compete with one another to become active, has been used to explain why we see bands of increased brightness at the edge of a colour difference when viewing Mach bands.

But Mach also made many contributions to psychology and physiology, including his anticipation of gestalt phenomena, his discovery of the oblique effect and of Mach bands, an inhibition-influenced type of visual illusion, and especially his discovery of a non-acoustic function of the inner ear which helps control human balance.