All the Colours of the Rainbow – Medieval and Modern Accounts of Human Colour Perception

The De colore – Robert Grosseteste's treatise on colour written c. 1225 – is a dense text of fewer than 400 words that presents an abstract account of the perceptual variation in colour, linked to specific properties of light and matter. It introduces new terminology in a way that assumes very tight definitions but that permits no straightforward translation or interpretation.

Professor Hannah Smithson

Professor Hannah Smithson's research focuses on the neural mechanisms that underlie perception and how the eye and brain process visual information. Her research addresses this question primarily through psychophysical experiments – inferring the perceptual processes that underlay particular patterns of human performance on tasks with carefully selected visual stimuli.

I am particularly interested in the perception of colour. How are the signals from the three classes of cone photoreceptors processed to give rise to our perceptions of hue, saturation and brightness? What are the neural circuits of comparison and combination that permit the efficient transmission of colour information from retina to cortex? How does our perception of colour depend on our ability to identify objects and light sources in the visual scene? I am also interested in the way in which our visual systems process rapid sequences of visual events – a sequence of changes in illumination, a sequence of images from successive fixations, or the complex trajectory of a moving object.