

Is free will really "free"? Your actions can be predicted from your brainscan - Jun8
http://opinionator.blogs.nytimes.com/2011/10/19/what-makes-free-will-free/

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jessriedel
These neuroscientists are very confused if they think they can say anything
useful about free will, or evil, or the like. Unless they are going to provide
empirical evidence against _determinism_ itself, there's nothing those brain
scans are going to tell them about these issue.

Will Wilkinson argues the point here:

<http://bigthink.com/ideas/40538>

~~~
joeyo
I must confess, I don't understand your argument, nor the one at the linked
blog post. Why do they need to show evidence _against_ determinism?

There is a growing body of evidence that choices are "made" by the brain long
before we are consciously aware of them. The most parsimonious explanation for
these data is that the brain comes to a decision through a mechanistic process
of integrating evidence and then the conscious self is informed of that
decision. It's at this point that we feel that we have made a choice.

One nice prediction of this theory is that brain disorders that disrupt the
communication of the decision making circuitry and the parts of the brain that
are normally informed about it should produce the impression that ones choices
are being externally controlled. And indeed there are a wide variety of
disorders with these features (schizophrenia, alien hand syndrome, etc).

Some of the pieces are missing--what is this pathway and which brain
structures are involved in the perception of agency--but I think it makes a
lot more sense than believing in non-causal free will.

EDIT: Another compelling piece of evidence comes from brain stimulation. When
you electrically stimulate the surface of the brain (say, as part of a
surgical procedure to localize a tumor) you will find areas that evoke
movements of the arm, eyes, legs, etc. The experiment is: you do this without
telling the patient exactly when it will happen and then afterwards ask them,
"why did you move your arm?" Many people will confabulate and say, "I felt
like it" or "you asked me to". This isn't always the case: sometimes people
will report that their arm felt like it moved "on it's own", but I think it is
very suggestive.

~~~
jessriedel
The point is that if physical law is deterministic, then none of these
experiments are going to tell you anything about free will that you didn't
already know. Yes, they tell you that people are confused when they say "I
decided to do X" when, in fact, the normal decision making part of the brain
wasn't involved with doing X because X was actually artificially stimulated by
the experimenter's electric probe. But if you believe in determinism already,
what does this tell you _about the possibility of free will_? Given
determinism, we _already know_ that all actions and choices can be traced back
to previous causal events, so we _already know_ people are confused when they
think that their choices are somehow not caused by previous events but come
from their soul or whatever.

So none of the empirical facts are under dispute. The question then is a
purely philosophical one: is there a sensible notion of free will given
determinism? Should (normative claim!) we treat people like they have free
will, i.e. punish/reward them for their actions?

~~~
nooneelse
> "The point is that if physical law is deterministic..."

Under current QM, it doesn't appear that things like alpha decay happen
predictably or at one time vs another for any reason. And that isn't simply a
problem of not knowing the state of the system; hidden variable theories have
not met with empirical success.

So, imagine we could have two universes, both with our laws of physics, and
identical up to time=0. Current QM allows that at t=1 in one universe
radioactive decay occurs which then produces chain of events A, while in the
other universe at t=1 there is no decay and thus chain of events B. Why then
call these universes and their physical laws deterministic? They seem rather
not.

~~~
jessriedel
I'm a physics grad student doing work in quantum decoherence, so I'm aware of
all this. When discussing free will, "determinism" really is shorthand for the
idea that the cause of all events can be traced back to previous events in
known physics, including fundamental probabilistic events. The key claim is
that there is no "soul" (or any other causal source which cannot in-principle
be explained by known physics) producing choices.

(Yes, you bundle up all the probabilistic quantum events which occur in your
brain and identify that as "free will", but I don't think most people would
find that compelling. Not the least of which because then it seems like a
plutonium atom has just as much right to the term "free will" as you do.)

~~~
nooneelse
Well, I'm glad then that we get to skip the bit were I have to spell out the
facets of the argument I made. (Over on reddit bringing this up usually means
me having to gently prod the other person to read up on hidden variable
theories so they can tell me if that is what they meant by phrases like
"something determines it we just can't see what".)

I'm actually a compatibilist about "free will", so I've no need for a ghost in
the machine or to be flipping quantum coins in my head. The point of my
comment was simply to point out that "our universe is deterministic", full
stop, isn't a warranted premise by current evidence. If you only meant
"adequately deterministic" by "deterministic", fine and dandy. However, I
don't know anything that actually stops the two causal chains A and B in my
thought experiment from being macroscopically very different. So skipping the
"adequately", I feel, gives those not familiar with the details a misleading
impression that we can unproblematically think of ourselves as just in the old
clockwork universe. (Thus the kinds of phrasing I see a lot on reddit from the
loosely-informed on such matters.)

(Edits: silly grammar and spelling stuff.)

~~~
jerf
It should be pointed out that Bell's inequalities only rule out the existence
of classical hidden variables being able to explain quantum effects, which if
one understands the history behind the question makes sense. Technically it
doesn't (and can't) rule out hidden variables that are "quantum" in nature (if
you'll permit me the shorthand), but from our perspective those are the very
definition of a needlessly multiplied entity in the Occam's Razor sense.
Nevertheless, that simply means they aren't useful to us, not that they don't
exist. It is certainly possible to imagine that we exist in a simulation in
which the simulation is "quantum", but whenever a random number is needed, a
psuedorandom and deterministic source is used instead. We'd never be able to
tell from the inside, unless there was something very, very broken about the
psuedorandom number generator, which given that we are talking about something
with the capacity of simulating our entire universe seems unlikely (unless
intentional).

Basically, our universe could be deterministic from the outside while being
nondeterministic on the inside, in the sense that those of us on the inside
will never be able to collect enough information to predict our own universe's
evolution from the inside. (In other news, I'm in the camp that considers
"randomness" and "lack of knowledge" to be two phrasings of the same thing, so
it's sensible to talk about things being deterministic(/"not random") from one
viewpoint but nondeterministic from another.)

This is just FYI since it's relevant, not disagreement.

~~~
jessriedel
> It should be pointed out that Bell's inequalities only rule out the
> existence of classical hidden variables being able to explain quantum
> effects

No, Bell's inequality rules out _all_ local hidden variables, whether those
variables are generated deterministically or not. Bell's inequality does _not_
say anything about the existence of intrinsic randomness in the universe; it
says something about locality.

(Of course, the fact that quantum mechanics is intrinsically random as far as
we can tell made it conceptually very difficult to formulate the correct
inequality, although the math was simple. That's why the original EPR paper
couldn't quite nail down what was so weird about QM, even though they were on
the right track. It was an astounding feat by John Bell.)

------
Symmetry
I'm just going to put this here <http://wiki.lesswrong.com/wiki/Free_will>

EDIT: Ok, I'll just say that it's more useful when facing a difficult question
like this that isn't even guaranteed to have a correct answer to first ask
what causes the question. That is asking, "Why do we think we have free will",
before going back to the question of whether or not it exists.

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brudgers
"We must believe in free will -- we have no choice."

Issac Bashevis Singer

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Jun8
"[A recent article in _Nature_ ] show that, prior to the moment of conscious
choice, there are correlated brain events that allow scientists to predict,
with 60 to 80 percent probability, what the choice will be."

It's amazing how correct the Architect was and at the same time how limited:
"But we already know what you're going to do, don't we? Already I can see the
chain reaction, the chemical precursors that signal the onset of emotion,
designed specifically to overwhelm logic, and reason." Evidently, at the
neurological level, there is no "logic" or "reason" as he uses those terms.

