Investigating the underlying mechanisms of categorical perception of colour using the event-related potential technique

Categorical perception (CP) of colour is demonstrated by faster and more accurate discrimination of colours that cross a category boundary than equivalently spaced colours from the same colour category. Despite a plethora of behavioural research investigating the origin and nature of colour CP, the underlying mechanisms involved in the effect are still unresolved. A recent body of work has made use of the Event-Related Potential (ERP) technique, which involves the measurement of event-related brain potentials at the scalp, enabling exploration of the time course of neural processes that are involved in colour CP. The merits of the ERP technique are presented and five studies that have used this approach to investigate colour CP and colour categorisation are reviewed. Each is discussed in relation to the debate about the origin and nature of colour category effects.