Seeing Colour in a Contemporary Light: from daylight to LED light, via old masters and a dress

29 October 2015, 6.00 PM - 29 October 2015, 7.00 PM

Anya Hurlbert (Professor of Visual Neuroscience, Director of the Centre for Translational Systems Neuroscience, Newcastle University)

LT1, School of Chemistry

 

In this talk, Professor Anya Hurlbert will illustrate the limits of colour constancy by describing experiments using tuneable multi-channel LED light sources, carried out both in the laboratory and in public installations.

Colour pervades the world, both inside and outside, made by man and nature. People see and respond to colour in food, furniture, fine art, and fashion; in the ruddy flush of healthy skin or the blue stain on mouldy cheese. Colour tells people whether fruit is ripe, which car is theirs, and what season it is. Yet although colours signify many things, colours are not physical things, but the result of perceptual processes that start in the eye and continue in the brain. Colour is inherently subjective and individual. This variability of colour was brought home to millions of people with the #thedress, the internet phenomenon of spring 2015 which caused people to argue over whether a simple dress in a single photograph was white-and-gold or blue-and-black. In fact, the variability of reported colours elicited by #thedress demonstrates the power of colour constancy, a fundamental phenomenon of normal colour vision, which operates to stabilise object colours across the wide changes in illumination spectrum to which we are daily exposed. Colour constancy enables people to rely on colour as robust indicator of object properties, and is a prime example of a perceptual constancy. Colour constancy comes about through multiple mechanisms on different levels in the visual system. Our laboratory experiments suggest that these mechanisms have most likely evolved to achieve optimal colour constancy for naturally-occurring illuminations, and in particular for blue-ish daylight. When the illumination is ambiguous or artificial in crucial ways, colour constancy may break down, as it does in #thedress.

In this talk, Anya will illustrate the limits of colour constancy by describing experiments using tuneable multi-channel LED light sources, carried out both in the lab and in public installations. The latter include a mass psychophysics experiment at the National Gallery as part of the 2014 Making Colour exhibition, from which the data confirmed previous laboratory findings of better colour constancy for certain natural illumination changes as well as revealed new findings on colour name-changes under artificial illumination changes. These and other experiments also highlight the fact that the colours we see, and the constancy with which we see them, must evolve along with new technology that enables new and ever-changing illuminations.

Biography

Anya Hurlbert is Professor of Visual Neuroscience and Director of the Centre for Translational Systems Neuroscience at Newcastle University. She trained as a physicist (BA 1980, Physics, Princeton University), physiologist (MA 1982, Cambridge University), neuroscientist (PhD 1989, Brain and Cognitive Sciences, MIT), and physician (MD 1990, Harvard Medical School). Her main research interest is in understanding the human brain, through understanding the human visual system. She focusses on colour vision and its role in everyday visual and cognitive tasks, in normal development and ageing as well as in developmental disorders such as autism. She has particular research interests also in applied areas such as digital imaging and novel lighting technologies. One of her current research projects (HI-LED), funded by the EU FP7 programme, aims to understand how novel lighting technology may be used to optimise human health and performance. In 2004, she co-founded the Institute of Neuroscience at Newcastle, one of the UK’s foremost academic units focussed on neurosciences, uniting clinicians and basic scientists, and was Institute Director until 2014. Professor Hurlbert is active in the public understanding of science, and has devised and co-curated several science-based art exhibitions, most recently the an interactive installation (a film, lighting demonstration and mass public experiment) at the National Gallery, London, for its 2014 summer exhibition. She lectures widely on colour perception and art, and contributes to media programmes on visual perception. She is past Chairman of the Colour Group (GB) and currently Scientist Trustee of the National Gallery.

For more information, please visit the Bristol Vision Institute event page.

Register free of charge at the University of Bristol online shop.

Contact information

Register your place free of charge at the UoB Online shop (search for Anya Hurlbert).

For further information please contact BVI administrator, Jen Hawkins: j.hawkins@bristol.ac.uk

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