Recent research has suggested that not all grapheme-colour synaesthetes are alike. One suggestion is that they can be divided, phenomenologically, in terms of whether the colours are experienced in external or internal space. Another suggestion is that they can be divided according to whether it is the perceptual or conceptual attributes of a stimulus that is critical. This study compares the behavioural performance of 7 projector and 7 associator synaesthetes. We demonstrate that this distinction does not map on to behavioural (...) traits expected from the higher–lower distinction. We replicate previous research showing that projectors are faster at naming their synaesthetic colours than veridical colours, and that associators show the reverse profile. Synaesthetes who project colours into external space but not on to the surface of the grapheme behave like associators on this task. In a second task, graphemes presented briefly in the periphery are more likely to elicit reports of colour in projectors than associators, but the colours only tend to be accurate when the grapheme itself is also accurately identified. We propose an alternative model of individual differences in grapheme-colour synaesthesia that emphasises the role of different spatial reference frames in synaesthetic perception. In doing so, we attempt to bring the synaesthesia literature closer to current models of non-synaesthetic perception, attention and binding. (shrink)

In this chapter we examine the role of synaesthesia research within the broader context of the science of the mind and in particular the scientific study of consciousness. We argue that synaesthesia could be used as a model problem for the scientific study of consciousness, offering a novel perspective on perception, awareness and even social cognition. We highlight some of the lessons we have learnt from studying synaesthesia and areas in which we see synaesthesia research generating further insights into understanding (...) consciousness in the future. These include: Individual differences in conscious experience, the neural correlates of consciousness, how we construct the perceived world, and the development of consciousness. (shrink)