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Modern neuroscience: Room for the soul?

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Presentation on theme: "Modern neuroscience: Room for the soul?"— Presentation transcript:

1 Modern neuroscience: Room for the soul?
By John Beggs

2 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

3 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

4 Apollo’s chariot…

5 …or rotation of the earth?

6 Science killed Apollo. Will neuroscience kill the soul?

7 Dualism Body Mind Rene Descartes

8 Dualism Body and mind are separate The mind influences the body
Mind is the fundamental truth Rene Descartes

9 The modern view: monism
Antonio Damasio The brain produces the mind Body, or matter, is the fundamental truth

10 The conflict

11 The conflict Dualism: Just as mind is separate from the body, so Free Will, Ethics and God originate independently of the brain.

12 The conflict Dualism: Just as mind is separate from the body, so Free Will, Ethics and God originate independently of the brain. Monism: Just as the brain produces mind, so Free Will, Ethics and God are merely products of the brain.

13 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

14 Trying to explain different levels
macroscopic Trying to explain different levels mesoscopic blah blah microscopic

15 Cortical neurons from rat
~1010 neurons in human brain

16 Neurons generate voltage pulses
time voltage

17 Output is communicated by pulses through synapses
Memory? voltage time

18 Each neuron makes and receives many connections
~ 103 – 104 inputs ~ 103 – 104 outputs

19 If all the inputs exceed a threshold, the neuron will “fire”
out in Otherwise, it won’t

20 From the lab of David McCormick, Yale University

21 Logical operations: AND gate
If C has a threshold of 2, then it will fire only when A AND B fire A C B

22 Logical operations: OR gate
If C has a threshold of 1, then it will fire when A OR B fire A C B

23 Neurons form networks for processing information

24 Networks form the cortical “sheet”

25 The cortical sheet is responsible for higher functions

26 Beggs lab: small sections of the sheet
In collaboration with Alan Litke, UC Santa Cruz

27 Cortical structure is fairly uniform
Functions are partially localized in cortex Cortical structure is fairly uniform

28 EEG: Electro-encephalogram
Measures electrical activity through the skull

29 PET scan: Positron emission tomography
Measures glucose metabolism

30 fMRI: functional magnetic resonance imaging
Measures blood-oxygen level dependent responses

31 TMS: Transcranial magnetic stimulation
Bulk stimulates cortical regions

32 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

33 Every physical system that has been investigated has turned out to be either deterministic or random. “Both are bad news for free will,” he said. So if human actions can’t be caused and aren’t random, he said, “It must be — what — some weird magical power?” Michael Silberstein

34 Every spear tip we have ever seen has been made of either flint or bone. Both are bad news for tungsten. So if you claim that “tungsten” isn’t flint and can’t be bone, it must be – what – some weird new material? Cave Man 34

35 Dualist: Free will could exist independently of some of our brain processes.
Monist: Free will is produced by our brain, and might even be an illusion.

36 Benamin Libet’s experiment

37 Readiness potential precedes will to move

38 Therefore, there is no free will.
You thought you were deciding, but the decision was already made by that point! Therefore, there is no free will.

39 Not so fast…why not this:
Hand movement Prepotential Will Conscious reflection on decision “I have decided” Are there any examples of our awareness “lagging behind”? 39

40 Blindsight (Lawrence Weiskrantz) 40

41 So, conscious awareness can come after recognition

42 Also… Low-level processes are often automatic: I can tie my
shoes without thinking about it; I can drive home in my sleep. I have subconscious biases in my thoughts. Do these low-level processes truly reflect my will, or do they just reflect my tendencies?

43 Implicit Association Test (IAT) https://implicit.harvard.edu/implicit/
43

44 Implicit Association Test (IAT) https://implicit.harvard.edu/implicit/
or Good or Evil Laughter 44

45 So… My tendencies could be detected by electrodes, or by questions
that you ask me. But I do not necessarily act on all my tendencies. Example: I may be angry at someone, but I may chose to forgive them. Which takes more “willpower”: anger or forgiveness? 45

46 Free Will Free will may be a new type of process, as yet not fully understood.

47 Free Will Free will may be a new type of process, as yet not fully understood. Signals of my intentions may come before my sensed decision. But my choice may actually come before both.

48 Free Will Free will may be a new type of process, as yet not fully understood. Signals of my intentions may come before my sensed decision. But my choice may actually come before both. We have many strong automatic tendencies, but these are often overruled by our will.

49 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

50 Neuroethics “the examination of how we want to deal with the social issues of disease, normality, mortality, lifestyle, and the philosophy of living informed by our understanding of underlying brain mechanisms” -The Ethical Brain, by Michael Gazzaniga (emphasis his)

51 Prefrontal lesions: amoral behavior
Phineas Gage 51

52 Clearly, the health of our brain affects our ability to make moral choices.
But should we also look to the brain to tell us what is morally right? If you are a dualist, then no. If you are a monist, then yes.

53 Jonathan Cohen 53

54 A runaway trolley is hurtling down the tracks toward five people who will be killed if it proceeds on its present course. The only way to save them is to hit a switch that will turn the trolley onto an alternate set of tracks where it will kill one person instead of five. Most people hit the switch, saving five

55 Most people refrain from pushing, letting five die
As before, a trolley threatens to kill five people. You are standing next to a large stranger on a footbridge that spans the tracks in between the oncoming trolley and the five people. In this scenario, the only way to save the five people is to push this stranger off the bridge, onto the tracks below. He will die if you do this, but his body will stop the trolley from reaching the others. Most people refrain from pushing, letting five die 55

56 How does the brain respond to these two dilemmas?
“Emotional” areas (footbridge dilemma) “Cognitive” areas (trolley dilemma) 56

57 Going further: Should one smother a crying baby to death to protect the lives of many when enemy soldiers are approaching?  Here they compared the activation patterns in the brains between those who approve (utilitarians) and those who do not (deontologists). Deontologists: Don’t smother – “emotional” brain areas dominate Utilitarians: Smother – “cognitive” brain areas dominate 57

58 "The social-emotional responses that we've inherited from our primate ancestors undergird the absolute prohibitions that are central to deontology. In contrast, the 'moral calculus' that defines utilitarianism is made possible by more recently evolved structures in the frontal lobes that support abstract thinking and high-level cognitive control."  - Greene and Cohen 58

59 (Descriptive) Before, they were telling us how the brain responded to these dilemmas. (Prescriptive) Now they seem to be suggesting what we should do.

60 If they are correct… 60

61 If they are correct… Utilitarianism, being most recent, is correct 61

62 If they are correct… Utilitarianism, being most recent, is correct
Deontological views, being most ancient, are incorrect 62

63 If they are correct… Utilitarianism, being most recent, is correct
Deontological views, being most ancient, are incorrect Joshua Greene should give up his federal research funding, because we could feed many more people than just him with it. 63

64 If they are correct… Utilitarianism, being most recent, is correct
Deontological views, being most ancient, are incorrect Joshua Greene should give up his federal research funding, because we could feed many more people than just him with it. Intellectual superiority equates with moral superiority 64

65 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

66 Does God exist?

67 Does God exist? Dualist: God could exist independently of our minds

68 Does God exist? Dualist: God could exist independently of our minds
Monist: God only exists in our minds

69 Julian Jaynes (1920-1997) God’s voice?
That’s just the other hemisphere talking.

70 Temporal lobe epilepsy (TE)
There are…recent examples [of TE], like one of the founders of the Seventh Day Adventist Movement, Ellen White. Born in 1827, she suffered a brain injury aged 9 that totally changed her personality. She also began to have powerful religious visions. Disruptions of this general area may also lead to increased ritual behavior.

71 Michael Persinger 80% of Dr Michael Persinger's experimental subjects report that an artificial magnetic field focused on …[left temporal lobe] brain areas gives them a feeling of 'not being alone'. Some of them describe it as a religious sensation.

72 Scientists like Andrew Newberg want to see just what does happen during moments of faith. He worked with Buddhist, Michael Baime, to study the brain during meditation. By injecting radioactive tracers [PET scan] into Michael's bloodstream as he reached the height of a meditative trance, Newberg could use a brain scanner to image the brain at a religious climax. So, religion is something that only happens occasionally?

73 Out-of-body experience?

74 Even Richard Dawkins…

75 The “God Module” V.S. Ramachandran People with temporal lobe epilepsy
had religious hallucinations After seizures, they were more prone to prefer religious words over erotic words. Control group preferred erotic words. V.S. Ramachandran

76 I see my wife; she produces activity in my visual cortex
Seizure or stimulation causes activity in my visual cortex even when my wife is not there Therefore, my wife is always an illusion? 76

77 Religion is not just: Feeling another presence
An out-of-body experience Ritual A climactic moment of faith

78 Just because activity in the brain correlates with experiences of God does not mean that God does not exist.

79 Outline Introduction Neuroscience background Free Will Ethics God
Conclusions

80 Conclusions Mental functions are produced by the brain 80

81 Conclusions Mental functions are produced by the brain
This includes mechanisms of will, moral choice, and perceptions of God 81

82 Conclusions Mental functions are produced by the brain
This includes mechanisms of will, moral choice, and perceptions of God From this it does not follow that: 82

83 Conclusions Mental functions are produced by the brain
This includes mechanisms of will, moral choice, and perceptions of God From this it does not follow that: Free will is an illusion 83

84 Conclusions Mental functions are produced by the brain
This includes mechanisms of will, moral choice, and perceptions of God From this it does not follow that: Free will is an illusion Utilitarianism is correct 84

85 Conclusions Mental functions are produced by the brain
This includes mechanisms of will, moral choice, and perceptions of God From this it does not follow that: Free will is an illusion Utilitarianism is correct God is an illusion

86 Accept the science, but be critical of the non-scientific conclusions.
86

87 Other interesting topics
“Mind reading” fMRI scans Remote control of rats Neural control of prosthetic limbs Mentally moving a cursor for shut in patients Closed loop experiments: “Brain in a dish” Split brain experiments Hemineglect Prosopagnosia The case of H.M.; no new memories “Gay” rams? Spiritual machines? 87

88 Modern neuroscience: Room for the soul?
Thanks! By John Beggs 88

89 Successfully uploaded 9. 6MB file NeurosceinceRoomForSoulBeggs. ppt
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90 Religious experience has a cognitive component
Differences between happy emotions and religious thoughts involve cognitive areas 90


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