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The challenge from Neuroscience

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  1. The challenge from Neuroscience ‘The brain begins to seem like a magic box, a font of sorcery…how can sending an electric current into a bunch of cells produce conscious experience? What do electricity and cells have to do with conscious subjectivity? How could a conscious self exist inside such a soggy clump?’ - Colin McGinn, The Mysterious Flame

  2. What’s up What does Neuroscience tell us about: • Whether the mind is simply the brain • Whether we are free

  3. Is the mind distinct from the brain?

  4. Phineas Gage • Survived accident in which a large iron rod went totally through his head • Destroyed much of his left frontal lobe • Subsequent personality changes (?)

  5. The Gage puzzle Personality Mind Brain Brain part

  6. Can science solve the mystery of consciousness?

  7. What’s Pinker’s argument? “Modern neuroscience has shown that there is no user. ‘The soul’ is, in fact, the information-processing activity of the brain.”

  8. What is Pinker’s argument? • Changes to the brain cause changes in the mind • If (1) is true, then the mind is reducible to the brain. • Therefore, the mind is the brain. Evidence from Neuroscience Obvious

  9. Good argument? • Changes to the weather cause changes in your lifestyle. • If (1) is true, then your lifestyle is reducible to the weather. • Therefore, your lifestyle is the weather.

  10. What is Pinker’s argument? • Changes to the brain cause changes in the mind • If (1) is true, then the mind is reducible to the brain. • Therefore, the mind is the brain. Evidence from Neuroscience Obvious Causal link doesn’t entail identity of linked entities

  11. What is Pinker’s argument? • Everything about the mind can be explained in terms of the brain. • If (1) is true, then the mind is reducible to the brain. • Therefore, the mind is the brain. Evidence from Neuroscience Simplicity

  12. Compare Everything about the mind can be explained in terms of the brain. Everything about you can be explained in terms of the weather. The mind is affected by the brain You are affected by the weather.

  13. A puzzle My Soul Physical changes to brain Thinking, feeling, etc Immaterial substance capable of thinking, feeling, etc

  14. Appearance & reality What seems to be What is Memory is a single unified phenomenon Many different memory systems that can be disassociated with one another

  15. Appearance & reality What seems to be What is Many different, detachable memory systems at the neural level Memory is a single unified conscious experience Is there really a conflict?

  16. Problem of Consciousness • Easy problem • Correlation between mental states & brain states • Hard problem • How the mind is just the brain • Laws explaining correlation • Origin of mind

  17. The general argument • If I have the property P, but my body lacks the property P, then I am not the same thing as my body. • I have the property P, but my body lacks the property P. • Therefore, I am not the same thing as my body. Diversity of Discernibles Reflection Conclusion

  18. The Mental & the Physical No apparent physical properties Length, mass, texture Intentionality No apparent intentionality Privileged access No privileged access Logically possible to exist without the physical Logically impossible to exist without the physical

  19. Relevant readings • “Can Neurobiology Teach Us Anything About Consciousness?”(Churchland) • “The Puzzle of Conscious Experience” (Chalmers) • “The Mysterious Flame” (McGinn)

  20. Libet & the Science of Freedom

  21. 2 views of action Circumstances Agent Intention Circumstances Agent Intention “Incline without necessitating”

  22. Argument from Deliberation • Deliberation indicates we have the power to choose • Therefore, it is reasonable to think we have the power to choose, unless we have reason to think otherwise General observations of behavioural patterns The findings of neuroscience and cognitive psychology

  23. Why are people so predictable? • Strong correlation between circumstances & behaviour Hume: “Everyone acknowledges that there is much uniformity among the actions of men in all nations and ages, and that human nature remains the same in its forces and operations.”

  24. “If an intimate friend of mine, whom I know to be honest and wealthy, comes into my house where I am surrounded by my servants, I rest assured that he isn’t going to stab me before he leaves, in order to rob me of my silver ink-well; and I no more suspect such behaviour from him than I expect the collapse of the house itself which is new, solidly built, and well founded.”

  25. Laws of behaviour? • We can understand behaviour by understanding background/circumstances? • Are we subject to psychological laws? • If we know all the relevant information, can we be certain of how someone will behave?

  26. Libet’s experiment Within 30 seconds, wriggle your finger whenever you choose. Don’t plan in advance. Watch the clock and note when you chose to wriggle your finger.

  27. Findings

  28. Findings • Steady increase in brain activity (RP) consistently preceded the time the agents cited as when they experienced the will to move. • On average, RP preceded the ‘experience of will’ by some 500 milliseconds. • Libet and others conclude that conscious will is not the initiator of voluntary acting • Instead it is a consequence of an unconscious physical process that triggers the action.

  29. Free will is an illusion "The timing of will, finally, seems to seal the fate of that elusive light bulb. The detailed analytical studies of the timing of action indicate that conscious will does not precede brain events leading to spontaneous voluntary action but rather follows them.” -Daniel Wegner, The Illusion of Conscious Will

  30. The illusion illustrated I make a choice. My brain responds. My body responds. My brain determines my choice. My brain gives me the experience of making my choice. My body responds.

  31. Recall: Fact about deliberation • Deliberate: Sleep or Exercise? • You believe: • that you can sleep or exercise • It is within your control whether you choose to sleep or exercise It is not. Already determined by brain :(

  32. Extremely crucial distinctions Willing to X Having urge = Will Will = Experience of will Experience of willing to X Having the urge to X

  33. Problem 1 • Will to wriggle finger was exercised when joining experiment • “Urge, desire, will, intention” • Intention to wriggle finger when urge is detected In passive state, no actual choice made

  34. Problem 2 • What should we expect to see if our experience of willing is accurate? • Consciousness is linked to the brain • Priming for decision? • Break in causal chain may not result in break in brain activity The empirical findings are inconclusive?

  35. Empirical information needs conceptual processing. After the empirical, comes the philosophical

  36. Delgado’s peculiar discoveries • Delgado discovered that stimulating various regions of the brain could cause all sorts of bodily motions • Including frowning, the opening and closing of the eyes, and movements of the head, arms, legs and fingers… • How do you think you would react when your brain is stimulated by a scientist?

  37. Human reactions • Not only did they act out the movements without surprise or fear, but they also produced reasons for them. • Example: • Electrical stimulation of the brain produced “head turning and slow displacement of the body to either side with a well-oriented and apparently normal sequence, as if the patient were looking for something.” • Repeated six times over two days, with similar outcomes

  38. Human reactions • The subject, who did not know about the stimulation, considered the activity spontaneous and offered reasons for it. • When asked “What are you doing?” he would reply, “I am looking for my slippers,” “I heard a noise,” “I am restless,” or “I was looking under the bed.”

  39. Analysis of Reasoning • Evidence for freedom based on experience • But manipulation could produce the same experience • Same experience indeed? (2) Even so, what does this prove?

  40. Evidence for main claim • Subject experience movement as voluntary although it was due to brain stimulation • Consistent correlation • Not surprised at movement • Offered reasons for movement

  41. Same experience? • Not voluntary • But participants tend to rationalise actions to make sense of movement • Confused reflex action with voluntary action • Actually voluntary • Brain stimulation lead to strong desire which subject acted on • Evidence not conclusive

  42. Analysis of Reasoning • Evidence for freedom based on experience • But manipulation could produce the same experience • Same experience indeed? (2) Even so, what does this prove?

  43. Even so, what does this prove? • Sensation of will can be produced, but need not always be this way? • E.g. brain stimulation can cause us to have perception of objects • Doesn’t prove all perceptions are inaccurate • Rational to take perception as accurate unless we have reason to think otherwise?