In this paper we wish to bring together two seemingly independent areas of research: synaesthesia and sensory substitution. Synaesthesia refers to a rare condition where a sensory stimulus elicits not only the sensation that stimulus evokes in its own modality, but an additional one; a synaesthete may thus hear the word “Monday”, and, in addition to hearing it, have a concurrent visual experien...

We show that the neurological condition of synaesthesia--which causes fundamental differences in perception and cognition throughout a lifetime--is significantly represented within the childhood population, and that it manifests behavioural markers as young as age 6 years. Synaesthesia gives rise to a merging of cognitive and/or sensory functions (e.g. in grapheme-colour synaesthesia, reading l...

A newly reported form of synaesthesia in which seeing visual motion induces auditory experiences challenges traditional ideas about the neural mechanisms of synaesthesia and may shed light on how the brain integrates information from sound and vision.

Research on synaesthesia is undergoing something of a renaissance, having initially been a hot topic in psychology and philosophy in the late 19th and early 20th centuries. One hundred years ago investigators failed to define an objective framework within which to characterise the phenomenon, and so interest in the topic waned. With the cognitive revolution and the rapid rise of new experimenta...

Synaesthesia is a condition defined by additional perceptual experiences, which are automatically and consistently triggered specific inducing stimuli. The associative nature of synaesthesia has motivated attempts to induce means learning. Two recent studies this kind highlighted the potential for plasticity even in adulthood, demonstrating that extensive training can generate not only behaviou...

In a small proportion of the normal population, stimulation in one modality can lead to perceptual experience in another, a phenomenon known as synaesthesia. In the most common form of synaesthesia, hearing a word can result in the experience of colour. We have used the technique of PET, which detects brain activity as changes of regional cerebral blood flow (rCBF), to study the physiology of c...

The induction of synaesthesia in non-synaesthetes has the potential to illuminate the mechanisms that contribute to the development of this condition and the shaping of its phenomenology. Previous research suggests that lysergic acid diethylamide (LSD) reliably induces synaesthesia-like experiences in non-synaesthetes. However, these studies suffer from a number of methodological limitations in...

Synaesthesia is a type of metaphor associating linguistic expressions that refer to two different sensory modalities. Previous studies, based on the analysis of poetic texts, have shown that synaesthetic transfers tend to go from the lower toward the higher senses (e.g., sweet music vs. musical sweetness). In non-literary language synaesthesia is rare, and finding a sufficient number of example...

The commentaries by Shanon (2003) and Pribram (2003) on our original article (Ramachandran & Hubbard, 2001) are stimulating and make a valuable contribution to the knowledge and thinking about synaesthesia, and indeed the mind in general. We were gratified to see the overall level of agreement with our general framework. For example, both of the authors endorse our connection between the percep...

Despite a recent upsurge of research, much remains unknown about the neurobiological mechanisms underlying synaesthesia. By integrating results obtained so far in Magnetic Resonance Imaging (MRI) studies, this contribution sheds light on the role of particular brain regions in synaesthetic experiences. First, in accordance with its sensory nature, it seems that the sensory brain areas correspon...