COLOURPROCESSING DEFICIT

   A generic term for a group of visual phenomena characterized by a marked loss or alteration of colours attributed to a lesion affecting the sensory cortex and/or white matter. Due to a colour-processing deficit, colours may either seem different in some way (i.e. darker or brighter), or they may be substituted by shades of grey. The group of colour-processing deficits comprises the classes * achromatopsia and * dyschromatopsia. Colour-processing deficits are traditionally distinguished from other types of anomalous colour vision, such as * colour vision deficiency and * chromatopsia.

   References

   Zeki, S. (1990). A century of cerebral achromatopsia. Brain, 113, 1721-1777.