Does synesthesia undermine representationalism? Gregg Rosenberg (2004) argues that it does. On his view, synesthesia illustrates how phenomenal properties can vary independently of representational properties. So, for example, he argues that sound/color synesthetic experiences show that visual experiences do not always represent spatial properties. I will argue that the representationalist can plausibly answer Rosenberg.

Extreme conditions like savantism, autism or synaesthesia, which have a neurological 2AH, UK 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 co- occur, it is worthwhile testing for an undiagnosed Autism Spectrum Condition (ASC). This is because savantism has an established association with (...) ASC, and the combination of ASC with synaesthesia may increase the likelihood of savantism. The implications of these conditions for philosophy of mind are introduced. (shrink)

Fodor claims that cognitive modules can be thought of as constituting a psychological natural kind in virtue of their possession of most or all of nine specified properties. The challenge to this considered here comes from synaesthesia. Synaesthesia is a type of cross-modal association: input to one sensory modality reliably generates an additional sensory output that is usually generated by the input to a distinct sensory modality. The most common form of synaesthesia manifests Fodor's nine specified properties of modularity, and (...) hence, according to Segal (1997), it should be understood as involving an extra module. Many psychologists believe that synaesthesia involves a breakdown in modularity. After outlining how both theories can explain the manifestation of the nine alleged properties of modularity in synaesthesia, I discuss the two concepts of function which initially motivate the respective theories. I argue that only a teleological concept of function is properly able to adjudicate between the two theories. The upshot is a further application of so-called externalist considerations to mental phenomena. (shrink)

Wager has argued that synaesthesia provides material for a counterexample to representational theories of the phenomenal character of experience. He gives a series of three cases based on synaesthesia; he requires the second and third cases to bolster the doubtfulness of the first. Here I further endorse the problematic nature of the first case and then show why the other two cases do not save his argument. I claim that whenever synaesthesia is a credible possibility its phenomenal character can be (...) understood in terms of misrepresentation. (shrink)

The aim of this article is to give both a sustained interpretation of Wittgenstein’s obscure remarks on the experience of meaning of language, synthaesthesia and secondary use and to apply his insights to recent philosophical discussions about synthaesthesia. I argue that synthaesthesia and experience of meaning are conceptually related to aspect-seeing. The concept of aspect-seeing is not reducible to either seeing or imaging but involves a modified notion of experience. Likewise, synthaesthesia involves a modified notion of experience. In particular, the (...) concept of synthaesthesia involves a secondary use of ‘experience’ and hence is intrinsically dependent on the primary use of language. Recent discussions tend to overlook this distinction between the primary and secondary use of language. (shrink)

This article supplements our earlier paper on synaesthesia published in JCS (Ramachandran & Hubbard, 2001a). We discuss the phenomenology of synaesthesia in greater detail, raise several new questions that have emerged from recent studies, and suggest some tentative answers to these questions.

Jones and Coleman are among a handful of otherwise normal as a child and the number 5 was red and 6 was green. This the- people who have synesthesia. They experience the ordinary ory does not answer why only some people retain such vivid world in extraordinary ways and seem to inhabit a mysterious sensory memories, however. You might _think _of cold when you no-man’s-land between fantasy and reality. For them the sens- look at a picture of an ice cube, (...) but you probably do not feel es—touch, taste, hearing, vision and smell—get mixed up in- cold, no matter how many encounters you may have had with stead of remaining separate. ice and snow during your youth. Modern scientists have known about synesthesia since Another prevalent idea is that synesthetes are merely being 1880, when Francis Galton, a cousin of Charles Darwin, pub- metaphorical when they describe the note C flat as “red” or say lished a paper in _Nature _on the phenomenon. But most have that chicken tastes “pointy”—just as you and I might speak of brushed it aside as fakery, an artifact of drug use (LSD and a “loud” shirt or “sharp” cheddar cheese. Our ordinary lan- mescaline can produce similar effects) or a mere curiosity. guage is replete with such sense-related metaphors, and perhaps About four years ago, however, we and others began to un- synesthetes are just especially gifted in this regard. cover brain processes that could account for synesthesia. Along We began trying to find out whether synesthesia is a gen- the way, we also found new clues to some of the most mysteri- uine sensory experience in 1999. This deceptively simple ques- ous aspects of the human mind, such as the emergence of ab- tion had plagued researchers in this field for decades. One nat- stract thought, metaphor and perhaps even language. ural approach is to start by asking the subjects outright: “Is this A common explanation of synesthesia is that the affected just a memory, or do you actually see the color as if it were right people are simply experiencing childhood memories and asso- in front of you?” When we tried asking this question, we did ciations.. (shrink)

We studied two otherwise normal, synaesthetic subjects who `saw' a speci¢c colour every time they saw a speci¢c number or letter. We conducted four experiments in order to show that this was a genuine perceptual experience rather than merely a memory association. (i)The synaesthetically induced colours could lead to perceptual grouping, even though the inducing numerals or letters did not. (ii)Synaesthetically induced colours were not experienced if the graphemes were presented peripherally. (iii)Roman numerals were ine¡ective: the actual number grapheme was (...) required. (iv)If two graphemes were alternated the induced colours were also seen in alternation. However, colours were no longer experienced if the graphemes were alternated at more than 4 Hz. We propose that grapheme colour synaesthesia arises from `cross-wiring' between the `colour centre' (area V4 or V8)and the `number area', both of which lie in the fusiform gyrus. We also suggest a similar explanation for the representation of metaphors in the brain: hence, the higher incidence of synaesthesia among artists and poets. (shrink)

(1) The induced colours led to perceptual grouping and pop-out, (2) a grapheme rendered invisible through ‘crowding’ or lateral masking induced synaesthetic colours — a form of blindsight — and (3) peripherally presented graphemes did not induce colours even when they were clearly visible. Taken collectively, these and other experiments prove conclusively that synaesthesia is a genuine percep- tual phenomenon, not an effect based on memory associations from childhood or on vague metaphorical speech. We identify different subtypes of number–colour synaesthesia (...) and propose that they are caused by hyperconnectivity between col- our and number areas at different stages in processing; lower synaesthetes may have cross-wiring (or cross-activation) within the fusiform gyrus, whereas higher synaesthetes may have cross-activation in the angular gyrus. This hyperconnec- tivity might be caused by a genetic mutation that causes defective pruning of con- nections between brain maps. The mutation may further be expressed selectively (due to transcription factors) in the fusiform or angular gyri, and this may explain the existence of different forms of synaesthesia. If expressed very diffusely, there may be extensive cross-wiring between brain regions that represent abstract concepts, which would explain the link between creativity, metaphor and synaesthesia (and the higher incidence of synaesthesia among artists and poets). Also, hyperconnectivity between the sensory cortex and amygdala would explain the heightened aversion synaesthetes experience when seeing numbers printed in the ‘wrong’ colour. Lastly, kindling (induced hyperconnectivity in the temporal lobes of temporal lobe epilepsy [TLE] patients) may explain the purported higher incidence of synaesthesia in these patients. We conclude with a synaesthesia-based theory. (shrink)

Gray argues that my three earlier counterexamples fail to refute representational theories of phenomenal character. I maintain that, despite Gray's arguments, each example does in fact work against the particular representational theory at which it is targeted. Further, I question whether my internalism regarding phenomenal character and Gray's externalism regarding modularity are in genuine conflict with one another.

Representationism is the view that the phenomenal character of an experience supervenes on its representational content. Synaesthesia is a condition in which the phenomenal character of the experience produced in a subject by stimulation of one sensory modality contains elements characteristic of a second, unstimulated sensory modality. After reviewing some of the recent psychological literature on synaesthesia and one of the leading versions of representationism, I argue that cases of synaesthesia, as instances of what I call the extra qualia problem, (...) are counterexamples to externalist versions of representationism. (shrink)