Much of synaesthesia research focused on colour, but not all cross-domain correspondences reported by synaesthetes are strictly sensory. For example, some synaesthetes personify letters and numbers, in additional to visualizing them in colour. First reported in the 1890s, the phenomenon has been largely ignored by scientists for more than a century with the exception of a few single-case report...

In grapheme-colour synaesthesia, letters, numbers, and words elicit involuntary colour experiences. Recently, there has been much emphasis on individual differences and possible subcategories of synaesthetes with different underlying mechanisms. In particular, there are claims that for some, synaesthesia occurs prior to attention and awareness of the inducing stimulus. We first characterized ou...

Synaesthesia is characterised by idiosyncratic ectopic sensations which commonly take the form of coloured visual impressions evoked by touch or hearing. We studied six late-blind individuals who have retained synaesthetic colour perception. Four of them had been without any form of genuine colour vision for more than 10 years. All perceived colours when they heard or thought about letters, num...

This study examines a group of synaesthetes who report colour sensations in response to music and other sounds. Experiment 1 shows that synaesthetes choose more precise colours and are more internally consistent in their choice of colours given a set of sounds of varying pitch, timbre and composition (single notes or dyads) relative to a group of controls. In spite of this difference, both cont...

Synaesthesia and absolute pitch (AP) are two rare conditions that occur more frequently within populations of artistic professionals. Current thinking surrounding synaesthesia AP their relationship to music perception form the focus this article. Given has rarely been discussed in literature, article surveys consolidates general neurobiological, psychological, behavioural evidence summarise wha...

In synaesthesia, certain perceptual or conceptual stimuli (called inducers), trigger an additional concurrent experience. For example, I.S., a digit–colour synaesthete, experiences the colour green whenever he sees the digit 7. Since Galton’s seminal report on synaesthesia [1], it has been a commonly held view that digit–colour synaesthesia is highly idiosyncratic: that is, the same inducer, fo...

Extreme conditions like savantism, autism or synaesthesia, which have a neurological basis, challenge the idea that other minds are similar to our own. In this paper we report a single case study of a man in whom all three of these conditions co-occur. We suggest, on the basis of this single case, that when savantism and synaesthesia cooccur, it is worthwhile testing for an undiagnosed Autism S...

Synaesthesia is a familial condition that gives rise to unusual secondary percepts. We present a large-scale prevalence study which informs our ideas on whether the condition is more prevalent in men or women. A number of studies over the last 20 years have suggested the condition is found more commonly in women, with up to six times more female synaesthetes than male. Other studies attributed ...