Despite the recent surge in research on, and interest in, synesthesia, the mechanism underlying this condition is still unknown. Feedforward mechanisms involving overlapping receptive fields of sensory neurons as well as feedback mechanisms involving a lack of signal disinhibition have been proposed. Here I show that a broad range of studies of developmental synesthesia indicate that the mechanism underlying the phenomenon may involve reinstatement of brain activity in different sensory or cognitive streams in a way that is similar to what (...) happens during memory retrieval of semantically associated items. In the paper’s final sections I look at the relevance of synesthesia research, given the memory model, to our understanding of multisensory perception and common mapping patterns. (shrink)

This paper provides a categorization of cross-modal experiences. There are myriad forms. Doing so allows us to think clearly about the nature of different cross-modal experiences and allows us to clearly formulate competing hypotheses about the kind of experiences involved in different cross-modal phenomena.

Kant argued that the perceptual representations of space and time were templates for the perceived spatiotemporal ordering of objects, and common to all modalities. His idea is that these perceptual representations were specific to no modality, but prior to all—they are pre-modal, so to speak. In this paper, it is argued that active perception—purposeful interactive exploration of the environment by the senses—demands premodal representations of time and space.

Is speech special? This paper evaluates the evidence that speech perception is distinctive when compared with non-linguistic auditory perception. It addresses the phenomenology, contents, objects, and mechanisms involved in the perception of spoken language. According to the account it proposes, the capacity to perceive speech in a manner that enables understanding is an acquired perceptual skill. It involves learning to hear language-specific types of ethologically significant sounds. According to this account, the contents of perceptual experience when listening to familiar speech (...) are of a variety that is distinctive to hearing spoken utterances. However, perceiving speech involves neither novel perceptual objects nor a unique perceptual modality. Much of what makes speech special stems from our interest in it. (shrink)

This paper presents forms of multimodal perceptual experience that undermine the claim that each aspect of perceptual experience is modality specific. In particular, it argues against the thesis that all phenomenal character is modality specific (even making an allowance for co-conscious unity). It concludes that a multimodal perceptual episode may have phenomenal features beyond those that are associated with the specific modalities.