Synaesthesia: supernormal integration?

Synaesthesia has been known to scientific research for over 100 years but has undergone something of a renaissance recently as new investigations begin to uncover its neurological basis. Rather than being an anomaly, it might offer beneficial insights into the basis of normal perception. A new study by Esterman et al. epitomises this current trend and claims to show that the posterior parietal cortex is a crucial locus of synaesthetic experience. As the posterior parietal cortex is commonly linked to normal sensory integration, Esterman et al.'s finding might lend support to the claim that synaesthesia is an extension of the normal perceptual processes assumed to occur in binding.