Perceptual RepresentationContent, Constancies and Phenomenal Consciousness

Chapter 4 starts from Lewis's Hypothesis of Phenomenal Information: information excludes alternatives.

The hypothesis of phenomenal information is the idea that phenomenal consciousness is informative. (…) According to David Lewis, there is an important hypothesis in this direction, which he calls 'The genuine hypothesis of phenomenal information,' which 'treats information in terms of elimination of possibilities' (Lewis, 1990, p. 94). (…) Note that while Lewis defines this genuine hypothesis of phenomenal information as necessarily excluding materialism, one need not do so. (…) I conjecture that when a space of possible representations, the 'map,' is indexed by the subject as a whole, then perception constitutively involves phenomenal information.

If information excludes possibilities, phenomenal character demands a structured quality space.

Each phenomenal character constitutively excludes a certain range of possibilities, and the possibilities that each phenomenal character excludes is structured according to difference and similarity relations. (…) Notice that a quality space is not just a set of discriminations, but a structured set of discriminations. (…) The structured set of information gives rise to many dimensions along which particular discriminations are related according to similarity and difference relations.

IIT enters because the thesis needs a principled answer to what makes many discriminations one intrinsic point of view.

According to Tononi's theory, there are two aspects that make the phenomenal experiences what they are. First, phenomenal experiences are rich in information. They are informative. Second, this information is integrated. (…) What is needed is ultimately 'an intrinsic point of view associated with the camera chip as a whole'. (…) There is no objective measure that uniquely settles which states should be grouped together; that is, there is no intrinsic measure of which alternative representations are relevant, and which are not.

Perceptual Representation as a definite coordinate in Qualia Space.

The 'map' part in the above example is the structured space of possible representations. (…) When Churchland speaks of indexing he means the precise way in which several such constancies are combined in a definite perceptual representational content. (…) The relation between 'map' and 'indexing' inherently appeals to structural information because information is understood here as the exclusion of possibilities; the map is understood as a structured set of possibilities, and the indexing is understood as the determination of one among many possibilities. (…) What this shows is that there are some exotic colors (phenomenal characters!) that figure in our color space that we are not even aware of, or worse yet, might consider impossible - such as 'impossibly dark yellow' and 'hyperbolic orange' (P. M. Churchland, 2005, pp. 548, 552). (…) The nature of the indexing remains mysterious and incomplete on MIMP.

The 2013 Case from Absence poses the silent-neuron question in terms of perceptual constancies.

Consider the difference between a born blind person and an individual with normal vision staring into a dark or empty room. One might say that the person born blind sees nothing. The person with normal vision might also happen to see nothing. However, they do not see nothing in the same way. (…) One might claim that the person with normal vision represents an absence of visual content because he or she has certain visual constancies that are currently inactive. However, these very same visual constancies are also inactive when the person with normal vision sleeps in dreamless sleep, and yet in that case we would not similarly say that he or she represents the absence of visual content. (…) Thus, one may wonder what is required for an inactive constancy to enter positively into the perceptual representational content as an absence. What is necessary for being aware of absences in this way?

Inspired by IIT, in this footnote I draw out a counterintuitive implication of understanding absences in terms of informational exclusion: the merely potential acquires ontological significance.

To see how one might begin to understand the problem of absences, consider that a bit of information can be represented by a light being on or off. An array of lights that could be on or off would give n bits and 2^n possibilities or states of the system; if we walk into the room and no light hits our eyes, but potentially could have, we have been informed just as much of the states of the lights as we would have been, had they all been on, or some other arbitrary combination. Thus, if we base our theory of mental representation on an idea of information (as the exclusion of possibilities) the inactivity of relevant states should count just as much as active ones.

This is the tension the Timeslice Argument turns on.

The force of Fisher's article stems from deep intuitions we have about the world that jointly cannot be true. On the one hand, it is intuitive that the phenomenal character of green, for instance, cannot be isolated to a single, say, neuron, or a single specific point in time, but must involve some spatio-temporal context. On the other hand, consciousness seems unitary and irreducible. Thus, there is a gap between a process taking some physical time, involving many elements and reaching from the past into the future, and a unitary singular phenomenal character of green.

Read the full TimeSlice Argument appendix, or the passage in the thesis. The appendix was cut before submission.