Topic: colour

An object’s colour, brightness and pattern are all influenced by its surroundings, and a number of visual phenomena and “illusions” have been discovered that highlight these often dramatic effects. Explanations for these phenomena range from low-level neural mechanisms to high-level processes that incorporate contextual information or prior knowledge. Importantly, few of these phenomena can currently be accounted for when measuring an object’s perceived colour. Here we ask to what extent colour appearance is predicted by a model based on the principle of coding efficiency. The model assumes th

Colour vision plays important roles in regulating animal behaviour, yet understanding of how such information is processed in the brain is still incomplete. Here I discuss our work addressing this issue in mice where, despite aspects of retinal organisation that might suggest limited capacity for colour vision, we find evidence of extensive cone-dependent spectral opponency across subcortical visual centres. In particular, our data both reveals important contributions of such colour signals to non-image-forming functions (regulation of the circadian system) but also indicate surprisingly sophi

Colour vision is based on circuit-level comparison of the signals from spectral distinct types of photoreceptors. In our own eyes, the presence of three types of cones enable trichromatic colour vision. However, many phylogenetically ‘older’ vertebrates have four or more cone types, and in almost all their cases the circuits that enable tetra- or possibly even pentachromatic colour vision are not known. This includes the majority of birds, reptiles, amphibians, and bony fish. In the lab we study neuronal circuits for colour vision in non-mammalian vertebrates, with a focus on zebrafish, a tetr