Skip to main content
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1985 Sep;82(17):5983–5986. doi: 10.1073/pnas.82.17.5983

Contrast and assimilation in the perception of brightness.

R Shapley, R C Reid
PMCID: PMC390678  PMID: 3862112

Abstract

The rapid estimation of the brightness of objects is one of the nervous system's major visual tasks. Exactly how the eye and brain perform this basic task is still not understood. Two mechanisms that contribute to human perception of the brightness of objects have been identified previously: (i) the visual response to physical contrast and (ii) assimilation. Use of a unique visual display device allowed us to measure the relative importance of these two mechanisms. The present results reveal that assimilation is about half as effective as physical contrast in determining the apparent brightness of objects. These results imply that previous theories of vision--for instance, the retinex theory--will have to be revised; the importance of physical contrast must be weighted more strongly.

Full text

PDF
5984

Images in this article

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. HEINEMANN E. G. Simultaneous brightness induction as a function of inducing and test-field luminances. J Exp Psychol. 1955 Aug;50(2):89–96. doi: 10.1037/h0040919. [DOI] [PubMed] [Google Scholar]
  2. HELSON H. Studies of anomalous contrast and assimilation. J Opt Soc Am. 1963 Jan;53:179–184. doi: 10.1364/josa.53.000179. [DOI] [PubMed] [Google Scholar]
  3. Land E. H., McCann J. J. Lightness and retinex theory. J Opt Soc Am. 1971 Jan;61(1):1–11. doi: 10.1364/josa.61.000001. [DOI] [PubMed] [Google Scholar]
  4. Land E. H. Recent advances in retinex theory and some implications for cortical computations: color vision and the natural image. Proc Natl Acad Sci U S A. 1983 Aug;80(16):5163–5169. doi: 10.1073/pnas.80.16.5163. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Whittle P., Challands P. D. The effect of background luminance on the brightness of flashes. Vision Res. 1969 Sep;9(9):1095–1110. doi: 10.1016/0042-6989(69)90050-9. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES