Cognition 2 - Basic Processes
Reflective and Transmission of Wavelength-
● Colour of objects depends on their reflective and absorption properties
● E.g a surface that absorbs all other wavelengths apart from long, is red
● All white surface is one that reflects all wavelengths
Three Properties of colour-
● Hue refers to the colour quality of the light and corresponds to the colour names
we typically use.
● Saturation refers to the purity of light
● Brightness refers to the amount of light present
● Saturation and brightness are illustrated in red hue on powerpoint
Hue- Psychological correlation and wavelength-
● Our perception of hue (what we call colour) is not directly related to the nature of
wavelengths hitting the retina
● Created by our nervous system
Brightness- Psychological correlate of intensity-
● Brightness is a psychological concept
● Perceived brightness does not correlate to intensity or wavelength detected by
retina
Saturation- Psychological correlate of vividness-
● Vividness is also a psychological concept
● Perceived vividness of colour does not correspond to saturation detected by
retina
Saturation of vividness-
● Vividness is determined by the workings of the visual system.
● After intense stimulation the neurons responding to yellow stop responding to it
as much leading to changes in perception.
● In this case the original yellow now appears less vivid than the new yellow – even
though they are the same as far as our retina is concerned.
Colour Mixing-
● We can create 3 colours from the spectrum
● The Trichromatic Theory
The Trichromatic Theory-
● Starts with 3 cells in the retina called cones
Reflective and Transmission of Wavelength-
● Colour of objects depends on their reflective and absorption properties
● E.g a surface that absorbs all other wavelengths apart from long, is red
● All white surface is one that reflects all wavelengths
Three Properties of colour-
● Hue refers to the colour quality of the light and corresponds to the colour names
we typically use.
● Saturation refers to the purity of light
● Brightness refers to the amount of light present
● Saturation and brightness are illustrated in red hue on powerpoint
Hue- Psychological correlation and wavelength-
● Our perception of hue (what we call colour) is not directly related to the nature of
wavelengths hitting the retina
● Created by our nervous system
Brightness- Psychological correlate of intensity-
● Brightness is a psychological concept
● Perceived brightness does not correlate to intensity or wavelength detected by
retina
Saturation- Psychological correlate of vividness-
● Vividness is also a psychological concept
● Perceived vividness of colour does not correspond to saturation detected by
retina
Saturation of vividness-
● Vividness is determined by the workings of the visual system.
● After intense stimulation the neurons responding to yellow stop responding to it
as much leading to changes in perception.
● In this case the original yellow now appears less vivid than the new yellow – even
though they are the same as far as our retina is concerned.
Colour Mixing-
● We can create 3 colours from the spectrum
● The Trichromatic Theory
The Trichromatic Theory-
● Starts with 3 cells in the retina called cones
