ABSTRACT
The synaesthetic experience can vary from person to person; in particular there is an experiential difference between ‘projective’ and ‘associative’ synaesthesia. There are other forms of synaesthesia. For example, days of the week, dates, numbers, can embody personalities or, in some cases, genders. In another type of synaesthesia, numbers may appear in spatial ‘mental maps’, known as ‘number forms’, when a digit will occupy its own fixed position in space. In this form of synaesthesia, colour is experienced as a result of a musical sound such as a tone, key or timbre. The various studies of the phenomenon demonstrate that synaesthesia is a genuine perceptual reality. They also help us understand the neurological differences that occur in the synaesthetic brain. To a synaesthete, the colour experience of a musical chord, is as real and normal an experience as a non-synaesthete seeing printed colour on a sheet of paper.
