Abstract: In recent years many neuropsychologists have studied synaesthesia in whole brain. From these studies we find Synaesthetic colour experience in color synaesthesia can activate V4, but be not necessarily restricted to V4, and involve a network of brain areas(six brain locations activated). similarly, in other types of synaesthesia networks of brain areas were involved. some evidences have showed that synaesthetes have increased grey matter or white matter in area V4 or other areas, this implies there are structural differences of brain and genetic differences between synaesthetes and non-synaesthetes. works to look for the genes that determine synaesthesia are going on, and Some studies have showed that genetic basis may be found in genes which influence the development of connectivity in the brain, such as TBR1. These phenomenons still need to be tested in the future.

Key words: synaesthesia, networks of brain areas , genes