Online research in philosophy

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.

Synesthesia is a condition in which stimulation in one modality also gives rise to a perceptual experience in a second modality. In two recent studies we found that the condition is more common than previously reported; up to 5% of the population may experience at least one type of synesthesia. Although the condition has been traditionally viewed as an anomaly (e.g., breakdown in modularity), it seems that at least some of the mechanisms underlying synesthesia do reflect universal cross-modal mechanisms. We review here a number of examples of cross-modal correspondences found in both synesthetes and non-synesthetes including pitch-lightness and vision-touch interaction, as well as cross-domain spatial- numeric interactions. Additionally, we discuss the common role of spatial attention in binding shape and color surface features (whether ordinary or synesthetic color). Consistently with behavioral and neuroimaging data showing that chromatic-graphemic (colored-letter) synesthesia is a genuine perceptual phenomenon implicating extrastriate cortex, we also present electrophysiological data showing modulation of visual evoked potentials by synesthetic color congruency.

This encyclopedia entry provides an extended review of scientific work on synesthesia and reviews the philosophical literature that has drawn on synesthesia in order to arbitrate various disputes pertaining to topics such as the nature of consciousness, color, mental architecture, and perceptual representation, as well as several other topics.

Synesthesia is a condition in which stimulation of one sensory modality causes unusual experiences in a second, unstimulated modality. Although long treated as a curiosity, recent research with a combination of phenomenological, behavioral, and neuroimaging methods has begun to identify the cognitive and neural basis of synesthesia. Here, we review this literature with an emphasis on grapheme-color synesthesia, in which viewing letters and numbers induces the perception of colors. We discuss both the substantial progress that has been made in the past fifteen years and some open questions. In particular, we focus on debates in the field relating to the neural basis of synesthesia, including the relationship between synesthesia and attention and the role of meaning in synesthetic colors. We propose that some, but probably not all, of these differences can be accounted for by differences in the synesthetes studied and discuss some methodological implications of these individual differences.

The research presented in this volume demonstrates that it is no longer reasonable to ask whether or not synesthesia is real--we must now ask how we can account ...