Post on 23-Feb-2016
description
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
What’s up
What does Neuroscience tell us about:❄Whether the mind is
simply the brain❄Whether we are free
Is the mind
distinct from the brain?
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 (?)
The Gage puzzle
Personality Brain part
BrainMind
Can science solve the mystery of consciousness?
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.”
What is Pinker’s argument?
1. Changes to the brain cause changes in the mind
2. If (1) is true, then the mind is reducible to the brain.
3. Therefore, the mind is the brain.
Evidence from Neuroscience
Obvious
Good argument?
1. Changes to the weather cause changes in your lifestyle.
2. If (1) is true, then your lifestyle is reducible to the weather.
3. Therefore, your lifestyle is the weather.
What is Pinker’s argument?
1. Changes to the brain cause changes in the mind
2. If (1) is true, then the mind is reducible to the brain.
3. Therefore, the mind is the brain.
Evidence from Neuroscience
Obvious
Causal link doesn’t entail
identity of linked
entities
What is Pinker’s argument?
1. Everything about the mind can be explained in terms of the brain.
2. If (1) is true, then the mind is reducible to the brain.
3. Therefore, the mind is the brain.
Evidence from
Neuroscience
Simplicity
Compare
Everything about the mind can be explained in terms of the brain.
The mind is affected by the brain
Everything about you can be explained in terms of the weather.
You are affected by the weather.
A puzzle
My Soul
Immaterial substance capable of thinking, feeling, etc
Thinking, feeling, etcPhysical changes to brain
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
Appearance & reality
What seems to be What isMemory is a single unified conscious
experience
Many different, detachable memory
systems at the neural level
Is there really a conflict?
Problem of Consciousnes
s❄Easy problem
❊Correlation between mental states & brain states
❄Hard problem❊How the mind is just the
brain❊Laws explaining
correlation❊Origin of mind
The general argument1. If I have the property P, but
my body lacks the property P, then I am not the same thing as my body.
2. I have the property P, but my body lacks the property P.
3. Therefore, I am not the same thing as my body.
Diversity of Discernibles
Reflection
Conclusion
The Mental & the Physical
No apparent physical properties
Intentionality
Privileged access
Logically possible to exist without the
physical
Length, mass, texture
No apparent intentionality
No privileged access
Logically impossible to exist without the
physical
Relevant readings❄“Can Neurobiology Teach Us
Anything About Consciousness?” (Churchland)
❄“The Puzzle of Conscious Experience” (Chalmers)
❄“The Mysterious Flame” (McGinn)
Libet & the Science of Freedom
2 views of action
Circumstances Agent Intention
Circumstances Agent Intention
“Incline without necessitating”
Argument from Deliberation
The findings of neuroscience and cognitive psychology
General observations of
behavioural patterns
❄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
Why are people so predictable?❄Strong correlation between
circumstances & behaviourHume:“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.”
“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.”
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?
Libet’s experimentWithin 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.
Findings
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.
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
The illusion illustrated
My brain gives me the
experience of making my
choice.
My brain determine
s my choice.
My body responds.
My brain responds.
I make a choice.
My body responds
.
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 :(
Extremely crucial distinctions
Willing to XHaving urge = Will
Will = Experience of will
Experience of willing to X
Having the urge to X
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
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?
Empirical information needs conceptual processing.
After the empirical, comes the
philosophical
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?
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
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.”
Analysis of Reasoning❄Evidence for freedom based on
experience❄But manipulation could produce the
same experience(1)Same experience indeed?(2) Even so, what does this prove?
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
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
Analysis of Reasoning❄Evidence for freedom based on
experience❄But manipulation could produce the
same experience(1)Same experience indeed?(2) Even so, what does this prove?
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?