Bayesian Modeling of Perceiving: A Guide to Basic Principles

Philosophical reflection on perceptual consciousness has typically adopted a modality-specific perspective as its point of departure. According to this approach, an account of perceptual consciousness as a whole will simply fall out of an account of each of the various perceptual modalities. In this chapter, Tim Baynes argues against one manifestation of this atomistic approach to perceptual experience: the decomposition thesis. According to the decomposition thesis, a person?s overall perceptual experience can be identified with the sum of their modality-specific experiences. He examines objections to the decomposition thesis deriving from three sources: the phenomenal unity of consciousness, the existence of common sensibles, and the nature of multisensory integration, focusing in most detail on the last of these three objections

The mammalian central nervous synaptic cleft contains a high density of periodically organized complexes

Cryo-electron microscopy of vitreous section makes it possible to observe cells and tissues at high resolution in a close-to-native state. The specimen remains hydrated; chemical fixation and staining are fully avoided. There is minimal molecular aggregation and the density observed in the image corresponds to the density in the object. Accordingly, organotypic hippocampal rat slices were vitrified under high pressure and controlled cryoprotection conditions, cryosectioned at a final thickness of ≈70 nm and observed below -170°C in a transmission electron microscope. The general aspect of the tissue compares with previous electron microscopy observations. The detailed analysis of the synapse reveals that the density of material in the synaptic cleft is high, even higher than in the cytoplasm, and that it is organized in 8.2-nm periodic transcleft complexes. Previously undescribed structures of presynaptic and postsynaptic elements are also described