Synaesthesia: a Conceptualization (‘Synthesis’-) Phenomenon. Philosophical and Neurobiological Aspects

Neurobiological aspects of synaesthesia are discussed from the perspective of the broader philosophical topic of “syn-aisthesis” and the basic fundamentals of a neuropsychological understanding of perceptual inter-modal integration. Herein, the predominance of conceptualization processes in regard to top-down functions of the brain appears as a prerequisite for perception. Functional Magnet Resonance Imaging (fMRI) data of synaesthetes compared to controls are discussed, providing evidence for the theory that prefrontal and parietal conceptualization processes by themselves exert transmodal functions and thus contain properties of “binding”. A partial hyperactivity of such processes in synaesthesia may thus be a causal factor of this condition.