August, for example, is orange, quite long and evenly shaped, while September is light blue and bends round a corner.

Children are also often taught words and letters with music and shapes. The learning theory suggests that people with symptoms of synesthesia are recalling these experiences of early childhood ...

There are no indicators of their gender, colour or shape characteristics – they just intrinsically are. That’s part of the weird thing about synesthesia – it defies logic. But seeing ...