AS A COURTESY TO OUR SPEAKER AND AUDIENCE MEMBERS, PLEASE SILENCE ALL PAGERS AND CELL PHONES Please remember to sign-in by scanning your badge Department of Psychiatry Grand Rounds James M. Stedman, PhD. ABPP Clinical Professor Division of Child and Adolescent Psychiatry, Department of Psychiatry, UTHSCSA The Brain Accounts for Consciousness, Or Does It? A Brief Romp Through The Philosophy of Mind Learning Objectives: 1. Attendees will review some basic concepts of philosophy. 2. Attendees will learn about the Hard Problem of consciousness as formulated by Chalmers. 3. Attendees will become aware of the arguments regarding Property Dualism vs. Reductionism and vice versa. Dr. Stedman does not have any financial conflicts to disclose.
The Brain Accounts for Consciousness, Right? Or Does It? A Brief Romp Through The Philosophy of Mind James Stedman, Ph.D. ABPP
Why Present? Had two previous Grand Rounds by neuroscientists claiming that the brain accounts for consciousness. They have either denied any philosophical implications or glossed over them. But any consideration of consciousness runs head on into philosophy immediately.
But First, Some Philosophical Concepts METAPHYSICS/ONTOLOGY: the branch of philosophy considering the nature of reality 1. All Reality Is Physical: Physicalism, Materialism, Naturalism 2. All Reality Is NON Physical: Various Strains of Idealism 3. Reality Is Physical and NON Physical: Dualism
EPISTEMOLOGY: the branch of philosophy considering knowledge what we know and how Qualia: refers to ALL instances of PERSONAL, SUBJECTIVE, CONSCIOUS EXPERIENCE 1. Comes from Latin meaning what sort or what kind 2. Examples: MY perceived redness of the sunset, My perception of the sound of music, MY perception of the taste of Shiner
Begging The Question: A logical fallacy in which the premise of an argument presupposes the truth of the conclusion; the argument takes for granted what it is supposed to prove.
A Quick Review of Analytic Philosophy What? Reaction to the British Idealism of the time. An attempt to reground philosophy in realism. Method: a move toward detailed linguistic analysis of narrow philosophical issues, sometimes called Linguistic Analysis. Phases 1. B Russell and G E Moore 1910 1930: launched movement
2. Logical Positivism 1930 1945 and beyond philosophy of science tied meaning to Principle of Verification: all propositions, particularly scientific, are true IF AND ONLY IF verified by empirical observation. 3. Ordinary Language 1945 1965: L Wittgenstein; G Ryle: Language has no meaning outside of its ordinary use in context; philosophers think there is more but they are neurotics needing treatment.
4. 1965 Present: Eclectic but still based on language and semantics a. Metaphysics is BACK! No grand schemes though. b. Philosophy of Mind falls HERE. c. Philosophy of Mind is a creature of current Analytic Philosophy and tied to its methods and strategies.
d. Philosophy of Mind focuses on Consciousness in the context of the Mind/Body Problem. e. Philosophy of mind engages in thought experiments, including Possible World Semantics : Thought Experiments
f. Functionalism: Analytic Philosophy s solution to Consciousness and the Mind/Body Problem and the conceptual underpinning for cognitive psychology and neuroscience. 1) Claims that ALL mental states are constituted by their causal relations to one another and to sensory inputs and behavioral outputs. (read)
The Hard Problem: David Chalmers The Easy Problem: for him is the functional analysis of cognitive events from sensation/ perception to higher order cognition reasoning, categorization, thinking, etc. The HARD PROBLEM Claim: Phenomenal Consciousness our what it is like for me CANNOT be reduced to the functional scientific analysis described above.
What makes the hard problem hard and almost unique is that it goes beyond problems about performance and functions. To see this, note that even when we have explained the performance of all the cognitive and behavioral functions in the vicinity of experience perceptual discrimination, categorization, internal access, verbal report there still remains a further unanswered question: why is the performance of these functions accompanied by experience?
What Experiences Is He Talking About? Visual: the colors of a sunset that impact me in a subjective personal way. Auditory: Music can be analyzed by notes and tones and even at the physics level, but my personal feel of it, what it is like for me, seems to go beyond this. Conscious Thoughts: some have strong subjective components; some don t: thoughts one thinks to oneself and stream of consciousness seem to have a personal feel.
Awareness of Self: that background HUM that is somehow fundamental to consciousness and is there when other components are not, a DEEPER PHENOMENAL EXPERINCE OF ME. Nagel (1974) and What Is It Like To Be A Bat? : Short Version: Reflecting on what it is like to be a bat, no amount of objective data about brain mechanisms, biochemistry, evolutionary history, etc. will allow us to experience what is like for a bat to hunt by echolocation on a dark night.
Underlying Reasons for the Hard Problem What Is It About Subjective Phenomenal Consciousness That Generates The Hard Problem? Features Of Subjective Conscious Mental States 1. Immediacy: Conscious states are accessed in an immediate way. It appears that nothing comes between us and our conscious states. We access simply by HAVING THEM. We do NOT infer their presence by away of argument or outside evidence.
2. Indescribability: If someone has never seen red (a person blind from birth, for example), there is nothing informative we could say to convey to them the true nature of the qualia of red. 3. Independence: the apparent lack of connection between conscious qualities and anything else. We can imagine creatures, like us, but having no ability to experience.
4. Dennett notes that qualia are PRIVATE; exact interpersonal comparisons are impossible. SUMMARY: The challenge of the Hard Problem is to explain consciousness, given that it seems to give us immediate access to indescribable, independent, and private qualities. If we can t offer a satisfactory physicalist explanation for qualia, then we have to accept conscious qualities as DIFFERENT IN KIND and as a fundamental feature of our ontology.
The Responses: Chalmers Stirred Up A Hornet s Nest Eliminativism 1. Who: Dennett, Ryle, Churchlands 2. The Claim: Subjective Phenomenal Conscious Experience Does NOT Exist Strong Reductionism 1. Who: Most Cognitive Psychologists and Neuroscientists, Dennett, Churchlands, Armstrong (formulator of Functionalism)
2. The Claim: Consciousness exists but is reducible; that is, consciousness can be explained in terms of the ARRANGEMENT AND FUNCTIONING OF SIMPLER, BETTER UNDERSTOOD PARTS. 3. Theories (several): Global Workspace Theory: Conscious States Are Mental States Available For Processing By A Wide Range Of Cognitive Systems (read)
Global Workspace Theory CS Brief Memory (receiving/input) Uncs Cog Brain Processes-------Other Parallel Brain Processes The Global Workspace Outputs Generated by GWS
a. The Workspace can be functionally analyzed and tied to brain function. b. Still the question: Why are these states conscious? c. Dennett says: If a state is available in the GWS in this way, it is a Cs State (Is there a Question Beg here?)
d. Objections 1) Dalton: Criticized GW theory on grounds that, at best, it gives a functionalist account of consciousness but fails to address WHAT CS IS. 2) Strong Reductionism is committed to the proposition that all knowledge of Cs can be attained by Functional Analysis. If so, a blind person could gain full knowledge of color experience from a textbook.
Weak Reductionism 1. Who: Block, Loar, and many others 2. The Claim: Consciousness IS a basic phenomenon. It cannot be broken down into simpler non Cs elements BUT we can still identify Cs with physical properties (brain) as the most parsimonious theory. a. If Identity is established between a brain state and Cs state, that exhausts explanation. b. Phenomenal Concepts Strategy (R)
3. Objections: The Phenomenal Concepts Strategy itself appears to be vey similar to to Dualism
Interactionist Dualism Types 1. Substance: Descartes Consciousness is a fundamentally distinct KIND of thing from physical things; Classical Realism of Aristotle has similarities. 2. Property Dualism of Chalmers and others: a. Chalmers Own Words
The dualism here is a kind of PROPERTY DUALISM: Cs experience involves properties of an individual that are NOT entailed (caused by necessity) by the physical properties of that individual (he means brain), although they may depend lawfully on those properties (brain). Consciousness is a FEATURE of the world over and above the physical features of the world phenomenal properties are Ontologically Independent of physical properties.
b. Arguments for the Claim: he gives 5 1. NIGHT OF THE LIVING, BUT NOT QUALIA EXPERIENCING, DEAD: THE ZOMBIE DEFENSE: The idea of a zombie, though not actually existing, is LOGICALLY COHERENT and there are no contradictions in the POSSIBLE ZOMBIE MODEL. (R) a. Block argument (read)
2. INVERTED SPECTRUM: This occurs in a world physically identical to ours but in which facts about CS experience are different from facts in our world: A twin who is physically identical to me but with inverted CS I have a red experience and my twin has a blue experience.
3. EPISTEMIC ASYMMETRY: Chalmers and others point out the Consciousness is a surprising feature of the universe. OUR GROUNDS FOR BELIEF IN CONSCIOUSNESS DERIVE SOLEY FROM OUR OWN EXPERIENCE OF IT. (R) 4. THE KNOWLEDGE ARGUMENT: Jackson (1984): The Mary thought experiment
5. Argument From The Absence of Analysis: Reductionists have to explain how the existence of Consciousness might be ENTAILED (caused by necessity) by Physical Facts a. Chalmers says Functional Analysis is the only philosophical model available to reductionists for this task. b. However, functionalism can demonstrate only that Cs plays a functional role; NOT WHAT CS IS.
6. Objections to Property Dualism: Primarily those considered under Eliminitivism, and Strong Reductionism; Weak Reductionism is close to Property Dualism.
Take Home Messages 1. Neuroscience explanations of consciousness will always run into thorny philosophical problems at the ontological and epistemological levels. 2. Neither materialism nor dualism should be allowed to BEG THE QUESTION. Either must offer arguments in defense of their claims. 3. Classical Realism (Aristotle) also offers a dualist metaphysics of consciousness. In my opinion, this position is superior to Property Dualism but that s for another day.