Contrast theory
Introduction
The contrast effect is the increase or decrease, in relation to normality, of perception, cognition and performance, as a result of immediately prior or simultaneous exposure to a stimulus of greater or lesser value in the same dimension.
The contrast effect is ubiquitous in human and non-human perception, cognition, and resulting performance. Thus, for example, a person will appear more attractive than normal when compared to a less attractive person and less attractive when compared to a more attractive person.
Contrast Types
Simultaneous contrast
Identified by Michel Eugène Chevreul, simultaneous contrast refers to the way in which the colors of two different objects affect each other. The effect is more noticeable when compared between objects of complementary colors.[1].
In the image, both interior rectangles are exactly the same shade of gray; however, the top one appears to be a lighter gray than the bottom one, due to the background provided by the outer rectangles.
This is a different concept than contrast, which refers to the difference of an object in color and luminance, compared to its environment or background.
Successive contrast
Successive contrast occurs when the perception of the stimuli being seen is modulated by previously seen stimuli. For example, when you look closely at the dot in the center of one of the two colored disks in the top row for a few seconds and then look at the dot in the center of the disk in the same column in the bottom row, the bottom two disks appear to have different colors for a moment, even though they are identical colors.
Metacontrast and paracontrast
This is a type of contrast that involves both time and space.[2]
When half a circle is lit for 10 milliseconds, that is at its maximum intensity. If the other half is shown at the same time (but 20-50 ms later), there is mutual inhibition: the left side is obscured by the right half (metacontrast), and the center may be completely obliterated. At the same time, there is a slight darkening of the right side due to the first stimulus; This is for contrast.