Color Vision: Wavelengths, Theories, and Perception in Psychology

What is the visible spectrum range that people with trichromatic vision can detect?

400 to 700 nm

What does hue refer to in color perception?

The color quality of the light, corresponding to color names.

How is saturation defined in the context of color?

The purity of the light or the amount of white light mixed with the colored light.

What does brightness indicate in color perception?

The amount of light present.

What is additive color mixing?

The creation of a new color by adding one set of wavelengths to another set.

What is subtractive color mixing?

The creation of a new color by removing wavelengths from a light with a broad spectrum.

Define a metamer in color mixing.

A psychophysical color match between two patches of light that have different sets of wavelengths.

What are the three cone classes responsible for color vision?

S-cones (short-wavelength), M-cones (medium-wavelength), and L-cones (long-wavelength).

What does the trichromatic theory of color vision state?

The color of any light is determined by the output of the three cone systems in our retinae.

What does the opponent-process theory explain about color vision?

Color perception arises from three opponent mechanisms: red-green, blue-yellow, and black-white.

What evidence supports the opponent-process theory?

Color afterimages and hue cancellation studies, as well as the existence of cone-opponent cells.

How does color vision change from infancy to aging?

Infants have similar color categories to adults, but aging leads to decreased ability to see blue due to lens transparency loss.

What is color deficiency?

The condition of individuals missing one or more of their cone systems.

What is the difference between rod monochromats and cone monochromats?

Rod monochromats have no functioning cones, while cone monochromats have one cone type present.

What is protanopia?

A red-green color deficiency due to a lack of L-cones, more common in men.

What is deuteranopia?

A red-green color deficiency due to a lack of M-cones, also more common in men.

What is tritanopia?

A blue-yellow color deficiency due to a lack of S-cones, which is much rarer and not sex-linked.

What is cortical achromatopsia?

A loss of color vision due to damage to the occipital lobe.

What does constancy refer to in color vision?

The ability to perceive an object as the same under different conditions.

What is lightness constancy?

The ability to perceive the relative reflectance of objects despite changes in illumination.

What is color constancy?

The ability to perceive the color of an object despite changes in the amount and nature of illumination.

What is the Gelb effect?

An exception to lightness constancy where a dark object appears white when illuminated alone.

How does purple differ from violet?

Violet is a spectral color from 400 to 440 nm, while purple is a nonspectral color created by mixing blue and red wavelengths.

What challenges do dichromats face with color-coded signs?

They may confuse or not differentiate clearly between colors like red and green.

What advantage do dichromats have in certain situations?

They can see through some forms of color camouflage.