When an object looks red to an observer, the visual experience of the observer has two important features. The experience visually represents the object as having a property—being red. And the experience has a phenomenological character; that is, there is something that it is like to have an experience of seeing an object as red. Let qualia be the properties that give our sensory and perceptual experiences their phenomenological character. This essay takes up two related problem for a nonreductive account (...) of qualia. Some have argued that on such an account there is no room in a physicalist ontology for qualia. Section 1 shows how qualia might fit into a physicalist ontology. The second problem begins with the observation that there is a gap in scientific accounts of color experience; there is no explanation of why the features of the brain that determine our color experiences give those experiences their phenomenological character. Building on the results of Sect. 1, Sect. 2 develops an account of color perception that bridges this gap and shows how qualia give color perception its phenomenological character. To get a grip on the issues involved the paper begins by considering some aspects of a physicalist account of color. (shrink)

Based on the technique of pressure blinding of the eye, two types of after-image were identified. A physicalist or mind/brain identity explanation was established for a negative a AI produced by moderately intense stimuli. These AI's were shown to be located in the neurons of the retina. An illusory AI of double a grating's spatial frequency was also produced in the same structure and was both prevented from being established and abolished after establishment by pressure blinding, thus showing that the (...) location was not more central. The illusory AI was predicted from the known non-linearity in the retina and this is the first case of a clear cut type-type identity of a sensation and a neural process. Some implications for the concepts of the explanatory gap between neurology and consciousness and multiple neural realizations of conscious states and topic neutrality are discussed. (shrink)