The uses of colour vision: behavioural and physiological distinctiveness of colour stimuli

A M Derrington, A Parker, N E Barraclough, A Easton, G R Goodson, K S Parker, C J Tinsley, B S Webb

Research output: Contribution to journalArticlepeer-review

Abstract

Colour and greyscale (black and white) pictures look different to us, but it is not clear whether the difference in appearance is a consequence of the way our visual system uses colour signals or a by-product of our experience. In principle, colour images are qualitatively different from greyscale images because they make it possible to use different processing strategies. Colour signals provide important cues for segmenting the image into areas that represent different objects and for linking together areas that represent the same object. If this property of colour signals is exploited in visual processing we would expect colour stimuli to look different, as a class, from greyscale stimuli. We would also expect that adding colour signals to greyscale signals should change the way that those signals are processed. We have investigated these questions in behavioural and in physiological experiments.

We find that male marmosets (all of which are dichromats) rapidly learn to distinguish between colour and greyscale copies of the same images. The discrimination transfers to new image pairs, to new colours and to image pairs in which the colour and greyscale images are spatially different.

We find that, in a proportion of neurons recorded in the marmoset visual cortex, colour-shifts in opposite directions produce similar enhancements of the response to a luminance stimulus.

We conclude that colour is, both behaviourally and physiologically, a distinctive property of images.

Original languageEnglish
Pages (from-to)975-985
Number of pages11
JournalPhilosophical Transactions Of The Royal Society Of London Series B - Biological Sciences
Volume357
Issue number1424
DOIs
Publication statusPublished - 29 Aug 2002

Keywords

  • colour vision
  • image segmentation
  • object detection
  • figure-ground
  • monkey
  • vision
  • LATERAL GENICULATE-NUCLEUS
  • MONKEY VISUAL-CORTEX
  • NEW-WORLD MONKEY
  • RAPID CATEGORIZATION
  • CALLITHRIX-JACCHUS
  • PREFRONTAL CORTEX
  • CEREBRAL-CORTEX
  • NATURAL SCENES
  • LESIONS
  • DISCRIMINATION

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