Access and Phenomenal Consciousness Joe Lau Philosophy HKU

Readings Pinker’s article on reserve Ned Block’s papers “On a Confusion …” “How not to …” Other references : The introduction in Davies & Humphrey (eds.) Consciousness. The Nature of Consciousness edited by Block and others.

Phenomenal and Access X is P-conscious = there is something it is like to have X. X is A-conscious = The information contained in X is “poised” (directly available) for reasoning, reporting or rational control of action.

Examples P : Sensations : pains, itches, taste, … Visual imagination A : Conscious thoughts and reasoning Perhaps these are cases with both A and P?

What about pain? Pain is presumably P-conscious. But is it A-conscious? A-conscious states must be information-bearing states. Perhaps we should take pain as an information state. Information about location and extent of bodily injury.

Phantom limbs Many amputees still feel pain in their limbs after amputations. Explanation : they still have pain states that represent damage in a non-existing limb.

Correlation and identity A and P seem to be closely correlated. Maybe they are the same thing? Two different concepts can pick out the same thing. Would be nice if P can be reduced to A.

Explanatory problem Difficult to see how P can be explained. Suppose : “P = computational / neural state X.” But : “Why should having X feel like something?”

A-consciousness not problematic A-consciousness can probably be explained computationally. A-conscious Mental State Reasoning Linguistic Report Rational Action Control Memory

Against correlation No correlation, no identity. To show that P is not A, we need to find cases of : A without P, or P without A

A without P? Purported examples AI Computers Sleep-walking Zombies But how do we know that there is no P?

Better example Hartmann, J.A. et.al. (1991), “Denial of visual perception” Brain and Cognition 16, Patient at chance at telling whether a room is illuminated or dark. Small preserved island of V1. Can read single words and recognize faces when presented to the upper right part of the visual field. When asked how he knows the word or the face, he says “it clicks” and denies seeing the stimuli.

Comments How do we know he is not lying? Or self-deception? Is this possible? A creature might have a P-conscious mental state X without being able to report that X is P-conscious, even though the information in X is available. Maybe A is necessary but not sufficient for P?

P without A? Experience of background noise : P-conscious but not available? Aerodontalgia Toothache brought on by reduction of atmospheric pressure. There are also cases of post-operation reports of pain under general anesthesia.

Comment But these examples do not seem too convincing : Information can be poised for reasoning, reporting and action even if the systems for reasoning and reporting are inactive or too busy to access the information.

A Model