The Hurvich-Jameson (H-J) opponent-process network offers a familiar account of the empirical structure of the phenomenological color space for humans, an account with a number of predictive and explanatory virtues. Its successes form the bulk of the existing reasons for suggesting a strict identity between our various color sensations on the one hand, and our various coding vectors across the color-opponent neurons in our primary visual pathways on the other. But anti-reductionists standardly complain that the systematic parallels discovered by the (...) H-J network are just empirical correspondences, constructed post facto, with no predictive or explanatory purchase on the intrinsic characters of qualia proper. The present paper disputes that complaint, by illustrating that the H-J model yields some novel and unappreciated predictions, and some novel and unappreciated explanations, concerning the qualitative characters of a considerable variety of color sensations possible for human experience, color sensations that normal people have almost certainly never had before, color sensations whose accurate descriptions in ordinary language appear semantically ill-formed or even self-contradictory. Specifically, these "impossible" color sensations are activation-vectors (across our opponent-process neurons) that lie inside the space of neuronally possible activation-vectors, but outside the central 'color spindle' that confines the familiar range of sensations for possible objective colors. These extra-spindle chimerical-color sensations correspond to no reflective color that you will ever see objectively displayed on a physical object. But the H-J model both predicts their existence and explains their highly anomalous qualitative characters in some detail. It also suggests how to produce these rogue sensations by a simple procedure made available in the latter half of this paper. The relevant color plates will allow you to savor these sensations for yourself. (shrink)

Perception is often analysed as a process in which causal events from the environment act on a subject to produce states in the mind or brain. The role of the subject is an increasing feature of neuroscientific and cognitive literature. This feature is linked to the need for an account of the normative aspects of perceptual competence. A holographic model is offered in which objects are presented to the subject classified according to rules governing concepts and encoded in brain function (...) in that form. This implies that the analysis of perception must consider not only the fact that there is an interaction between the perceiving subject and the perceived object but also that the interaction is shaped by a system of concepts which the subject uses in thought and action. (shrink)

Pylyshyn rightly argues that the neuroscientific data supporting the involvement of the visual system in mental imagery is largely irrelevant to the question of the format of imagistic representation. The purpose of this commentary is to support this claim with a further argument.

The following analysis shows how developments in epistemic logic can play a nontrivial role in cognitive neuroscience. We argue that the striking correspondence between two modes of identification, as distinguished in the epistemic context, and two cognitive systems distinguished by neuroscientific investigation of the visual system (the "where" and "what" systems) is not coincidental, and that it can play a clarificatory role at the most fundamental levels of neuroscientific theory.

manner. The construction of the space-time structure that describes the dynamics of the neural network in a causal manner is a non-trivial problem. I critically review the idea of response selectivity as is applied to.