ATCS (lec09) Consciousness and Cognitive Science

Aims of today's lecture

(b) to elucidate the supposed first-person nature of conscious experiential states (qualia);

(c) to consider if consciousness can be explained in scientific terms;

(d) to examine some of the major current theories (empirical and philosophical) attempting to account for consciousness;

(e) to look at some puzzles that have been raised in relation to materialist theories

CONSCIOUSNESS - INTIMATE YET MYSTERIOUS

• Mysteries of mind in general:
• explaining intentional content
• rationality, intelligence
• perception, sensorimotor coordination
• mind-body causation
• is mind physicalo mind = braino mind = software?
• Mysteries of consciousness:
• subjective feel - how explained?
• privacy ( first-person nature - other minds problem) - how can I know your consciousness?

CONSCIOUSNESS and MIND

• Relation between consciousness and mentality?
• Cognitive scientists and others assume that many mental processes are unconscious

The friendly black cat that we ve been looking after while our neighbours are on holiday sat peacefully on the purple mat for two hours (example from Margaret Boden)

Perceptual processing Neurotic symptoms

e.g. exaggerated fear of germs

DOES CONSCIOUSNES = MIND ?

(a) Standard cognitive science view: many mental processes are in principle unconscious (but others are actually or potentially conscious)

(b) Everything that is mental is at least potentially open to conscious awareness (John Searle, The Rediscovery of the Mind, 1992, ch 7)

(c) A more extreme view: nothing is in the mind unless it occurs directly in consciousness (Galen Strawson, Mental Reality, 1994)

(d) Another extreme: It is the result of thinking, not the process of thinking that appears spontaneously in consciousness No activity of mind is ever conscious. (George Miller, 1962)

CONSCIOUSNESS and COGNITION

(The idea that consciousness may emerge from sufficiently complex systems [ the Internet wakes up ] )

(B) Consciousness as fundamentally distinct from cognition.

Private (1st-person, not 3rd-person)

Subjective point of view

ineffable
Privileged-reporting

(C) Access - consciousness versus phenomenal consciousness

ACCESS-CONSCIOUSNESS versus PHENOMENAL CONSCIOUSNESS

• See Ned Block, On a confusion about the function of consciousness (BBS, 1995)
• A-consciousness
• ability of subject to report on states
• availability of states for global control
• a cognitive kind of consciousness - explainable in familiar cognitive science terms
• P-consciousness
• the felt aspect of c. states (qualia)
• non-cognitiveo maybe non-physical??
• Some challenge the distinction (e.g. Dennett)

CONSCIOUSNESS and SCIENCE (1)

• Can there be a science of consciousness?
• The reductive cascade in science:
• psychology -> neuroscience -> biology -> chemistry -> physics
• physicalism/ reductionism
• do experiential phenomena fit in here?
• Dissent: Thomas Nagel: What is it like to be a Bato (1974)
• Science gives objective accounts of nature - the processes in themselves, and not as viewed (e.g. lightning)
• So science can t explain subjectivity - what it is like to have a particular kind of experience

CONSCIOUSNESS and SCIENCE (2)

• Possible views on the relation:

(b) consciousness is explained in functional or computational terms

(c) consciousness is a type of non-physical process (not reducible to either neural nor functional processes) -and therefore cannot be proper subject of scientific inquiry;

(d) consciousness is non-physical, but is nevertheless still a fit subject of scientific inquiry (because the scope of science may include non-physical processes);

(e) consciousness is inherently mysterious;

THEORIES OF CONSCIOUSNESS IN SCIENCE

• Physicalist theories
• Neural correlates of Consciousness (NCC) (eg Crick and Koch, Edelman)
• Quantum theories (Penrose/Hameroff)
• Higher-order cognition theories (eg Baars: Global Workspace, Rosenthal: Higher-Order Thought)
• Connectionist theories (eg Aleksander)
• Non-physicalist theories
• Naturalistic dualism (eg Chalmers)
• Panpsychism (Chalmers, Velmans, some quantum theorists)
• Mysterian theories
• (Nagel, McGinn)

THE HARD PROBLEM OF CONSCIOUSNESS (D Chalmers)

• D Chalmers, Facing up to the Problems of Consciousness , 1995
• Also known as the explanatory gap (J Levine, 1983)
• Explaining phenomenal C isn t like explaining

  liquidity (intermolecular forces) genetic inheritance (DNA) learning (computational theories)

• Any PURELY PHYSICAL story must leave out the SUBJECTIVE FEEL

CONSCIOUSNESS AND COMPUTING

• Why an AI theory of consciousness doesn't seem to work, even if an AI theory of cognition does:
• Cognitive mental properties (e.g. winning at chess, understanding language) seem to be often about performance, not feeling;
• A computational simulation of cognitive intelligence is as good as the real thing (Calculator)
• This won t work for qualia (first-person experience)
• AI-simulated qualia aren t just as good as real qualia - it makes a difference (Earthquake scenario);
• But: Dennett: this supposed division (between cognitive and phenomenal) is bogus

PUZZLES (a)

• Are conscious events IDENTICAL WITH neural events?
• Leibniz s law: if a = b then they share all their properties in common. Yet conscious events seem to be quite different from brain events!
• Are conscious events CAUSED BY neural events?
• McGinn: How can technicolour phenomenology arise from soggy grey mattero How could the aggregation of millions of individually insentient neurons generate subjective awarenesso We know that brains the de facto causal basis of consciousness, but we have, it seems, no understanding whatever of how this can be. It strikes us as miraculous, eerie, even faintly comic.

PUZZLES (b)

• Explanatory gap/Hard Problem
• how can any theory of brain structure/function account for phenomenal feel?
• Why/how did C. evolve?
• Distribution of C. in natural world -
• are gorillas, fish, bacteria, etc. consciouso Non-terrestrial life-formso Artificial mechanisms (current/future)?
• Epiphenomenalism -
• does the brain cause conscious experienceso is there causation the other way round?
• Are we cognitively/conceptually equipped to understand C?
• The Binding problem
• why/how do our experiences cohere/
• Dreams, hypnosis, meditation, drug-based states, etc.
• Multiple personality - alternating streams of consc.

PUZZLES (c) Intuition pumps

• Inverted qualia red-green swapping
• Knowledge argument (F Jackson) Mary, the colourblind neuroscientist
• Possibility (Modal) argument (Chalmers) Zombie universe

• Rejection of qualia (Dennett, Consciousness Explained, 1991) The coffee tasters

ZOMBIES

• Discussed by David Chalmers, The Conscious Mind, 1996 (but it s an old argument):
• Zombie earth:
• Physically identical to our earth (molecule-for-molecule);
• Inhabitants are behaviourally and functionally indistinguishable from us (3rd-person duplication);
• But they have no first-person experience
• The aim is to show that no materialist theory could explain consciousness

What is the zombie argument trying to proveo

• 1. If consciousness could be explained in physical terms then the explanation must be able to show how the relevant physical processes NECESSITATE the conscious processes;
• 2. If one process P NECESSITATES another process Q, then one would not be able to coherently imagine a world containing P unless it also contains Q;
• 3. But a zombie universe, which is physically identical to ours, is coherently imaginable;
• 4. So consciousness cannot be necessitated by any physical processes;
• 5. So consciousness cannot be explained in purely physical terms.

Does the zombie argument worko

• Possible positions:
• (a) The zombie supposition is incoherent: any being that exhibited sufficiently fine-grained behaviour and functionality of a conscious being WOULD BE a conscious being (Dennett);
• (b) The Z world is logically possible because our concepts of phenomenology aren t the same as our concepts of neural functioning, even though these different concepts are tied to the same property - namely properties of the brain: so it s metaphysically impossible (Brian Loar)

• Thomas Nagel: Conceiving the impossible and the mind-body problem (1997)
• Our current concepts of experience and neural processing imply a logical separation;
• But in a future science, we may have reason to reconceptualize our notions of experience so that they are logically tied to the underlying neural processes (such conceptual revisions are common in science)
• So a zombie universe may seem coherent according to present concepts, but not necessarily according to future concepts

Consciousness - some key QUESTIONS

• How hard is the hard problem of consciousness?
• Is it soluble?
• Can a materialist theory work?
• Is Consciousness an appropriate subject for scientific investigation?
• Is consciousness cognitive or computationa?
• How widely is consciousness distributed in the world? (Primates? bats? insects? plants? rocks?)