Seeing lightness in the dark
Authors: Ennis, R., Toscani, M. and Gegenfurtner, K.R.
Journal: Current Biology
Volume: 27
Issue: 12
Pages: R586-R588
ISSN: 0960-9822
DOI: 10.1016/j.cub.2017.05.008
Abstract:From intense sunlight in bright snow down to a moonless night in a dark forest, we can use light to recognize objects and guide our actions. This remarkable range mainly rests on having two different types of photoreceptors, the rods and the cones. The cones are active under daylight conditions, allowing high acuity and color vision. Rods are mainly active under very dim illumination conditions and have an exquisite sensitivity to light [1]. There are obvious detriments to visual perception in near darkness, such as a central scotoma, reduced motion perception [2], and most of all a lack of color [3]. There is only one type of rod, and thus intensity and wavelength differences cannot be disentangled when only the rods are active. This is captured well by the old saying “at night all cats are gray”, meaning that different colors inevitably get mapped onto different shades of gray. Here we show that the perception of lightness is also different for night vision: our results indicate that surfaces that appear to be white under daylight conditions, at best, appear medium gray under night vision, suggesting that activation of the cones is necessary for the perception of white.
Source: Scopus
Seeing lightness in the dark.
Authors: Ennis, R., Toscani, M. and Gegenfurtner, K.R.
Journal: Curr Biol
Volume: 27
Issue: 12
Pages: R586-R588
eISSN: 1879-0445
DOI: 10.1016/j.cub.2017.05.008
Abstract:From intense sunlight in bright snow down to a moonless night in a dark forest, we can use light to recognize objects and guide our actions. This remarkable range mainly rests on having two different types of photoreceptors, the rods and the cones. The cones are active under daylight conditions, allowing high acuity and color vision. Rods are mainly active under very dim illumination conditions and have an exquisite sensitivity to light [1]. There are obvious detriments to visual perception in near darkness, such as a central scotoma, reduced motion perception [2], and most of all a lack of color [3]. There is only one type of rod, and thus intensity and wavelength differences cannot be disentangled when only the rods are active. This is captured well by the old saying "at night all cats are gray", meaning that different colors inevitably get mapped onto different shades of gray. Here we show that the perception of lightness is also different for night vision: our results indicate that surfaces that appear to be white under daylight conditions, at best, appear medium gray under night vision, suggesting that activation of the cones is necessary for the perception of white.
Source: PubMed
Seeing lightness in the dark
Authors: Ennis, R., Toscani, M. and Gegenfurtner, K.R.
Journal: CURRENT BIOLOGY
Volume: 27
Issue: 12
Pages: R586-R588
eISSN: 1879-0445
ISSN: 0960-9822
DOI: 10.1016/j.cub.2017.05.008
Source: Web of Science (Lite)
Seeing lightness in the dark.
Authors: Ennis, R., Toscani, M. and Gegenfurtner, K.R.
Journal: Current biology : CB
Volume: 27
Issue: 12
Pages: R586-R588
eISSN: 1879-0445
ISSN: 0960-9822
DOI: 10.1016/j.cub.2017.05.008
Abstract:From intense sunlight in bright snow down to a moonless night in a dark forest, we can use light to recognize objects and guide our actions. This remarkable range mainly rests on having two different types of photoreceptors, the rods and the cones. The cones are active under daylight conditions, allowing high acuity and color vision. Rods are mainly active under very dim illumination conditions and have an exquisite sensitivity to light [1]. There are obvious detriments to visual perception in near darkness, such as a central scotoma, reduced motion perception [2], and most of all a lack of color [3]. There is only one type of rod, and thus intensity and wavelength differences cannot be disentangled when only the rods are active. This is captured well by the old saying "at night all cats are gray", meaning that different colors inevitably get mapped onto different shades of gray. Here we show that the perception of lightness is also different for night vision: our results indicate that surfaces that appear to be white under daylight conditions, at best, appear medium gray under night vision, suggesting that activation of the cones is necessary for the perception of white.
Source: Europe PubMed Central