Libet's "readiness potential" might be noise

[ignorantianescia]

New research suggests that the famous "readiness potential", often dragged in as evidence that decisions were pre-consciously determined before a conscious intention, might be the result of the discharge of neural noise. The authors argue it "may not reflect a decision at all". If so, it would refute an argument often used against free will.

www.newscientist.com/article/dn22144-brain-might-not-stand-in-the-way-of-free-will.html

Advocates of free will can rest easy, for now. A 30-year-old classic experiment that is often used to argue against free will might have been misinterpreted.

In the early 1980s, Benjamin Libet at the University of California in San Francisco, used electroencephalography (EEG) to record the brain activity of volunteers who had been told to make a spontaneous movement. With the help of a precise timer that the volunteers were asked to read at the moment they became aware of the urge to act, Libet found there was a 200 millisecond delay, on average, between this urge and the movement itself.

But the EEG recordings also revealed a signal that appeared in the brain even earlier – 550 milliseconds, on average – before the action. Called the readiness potential, this has been interpreted as a blow to free will, as it suggests that the brain prepares to act well before we are conscious of the urge to move.

This conclusion assumes that the readiness potential is the signature of the brain planning and preparing to move. "Even people who have been critical of Libet's work, by and large, haven't challenged that assumption," says Aaron Schurger of the National Institute of Health and Medical Research in Saclay, France.

[fortigurn]

Thanks for the link, it will be interesting to see how this plays out.

[ignorantianescia]

Fortigurn, if you want a more detailed description (though it is by a supporter of free will), you'll like this.

This and this are less detailed descriptions.

[sankari]

It baffles me that free will has so many opponents these days. Quite bizarre.

[unkleE]

Oct 29, 2012 9:39:44 GMT sankari said:

It baffles me that free will has so many opponents these days. Quite bizarre.

I'm interested why you say that?

I would have thought that if one is a naturalist, then every event must either be caused by previous events and natural laws, or must be random - what other things could cause events? But if this is true, then where is the scope for free choice? On that view, all our brain events are caused by previous events, external and within the brain, acting on the electro-chemistry of the brain.

So if one is a naturalist, it seems to me that one must logically hold that free will is an illusion, and it would require some ingenuity to find a place for free choice.

Of course Dennett can define free will simply as freedom from external coercion, but this is illusory, because even if one could trace the line of cause and effect in the brain back to birth without any external coercion, we obviously have no choice about our birth and our genes.

Much as I was reluctant to do so, I had to come to the view that free will is only possible if we are dualistic.

How do you see it differently?

[sankari]

Oct 30, 2012 3:10:58 GMT unkleE said:

I'm interested why you say that?

I've never seen a credible argument against free will from anyone. If humans don't have free will, we're doing a damn good job of faking it.

I would have thought that if one is a naturalist, then every event must either be caused by previous events and natural laws, or must be random - what other things could cause events? But if this is true, then where is the scope for free choice? On that view, all our brain events are caused by previous events, external and within the brain, acting on the electro-chemistry of the brain.

How does the fact that our brain events are caused by previous events preclude free will? I have the capacity to consider multiple courses of action before choosing one, and I can even change my mind halfway through.

So if one is a naturalist, it seems to me that one must logically hold that free will is an illusion, and it would require some ingenuity to find a place for free choice.

I think you're confusing categories. The fact that our mental processes involve chemical reactions seems quite irrelevant to me. Can you prove that one particular chemical reaction will necessarily result in one specific course of action every time, with no possibility of alternative actions?

Much as I was reluctant to do so, I had to come to the view that free will is only possible if we are dualistic.

How are you defining 'dualistic'?

How do you see it differently?

I believe the human capacity to make wilfully irrational decisions without any reference to self interest or external stimulus is evidence of free will.

[unkleE]

Oct 30, 2012 5:31:41 GMT sankari said:

How does the fact that our brain events are caused by previous events preclude free will? I have the capacity to consider multiple courses of action before choosing one, and I can even change my mind halfway through.

I am not arguing that free will doesn't exist, I am thinking about your original comment about not understanding why people don't believe in free will, and discussing how I think naturalism or physicalism implies determinism.

Of course you have the capacity to consider multiple causes of action, but can you really choose one or another quite freely, or does it just seem that way? As I understand things, a neuroscientist who was a physicalist would say that there is no "you" to make any choices apart from your brain. So making a choice has to be explained in terms of the fairly well understood processes of the brain. Those processes are determined by physical laws, previous brain states and external input. So how can "you" choose when "you" are merely the processes that are fully explicable (and in principle predictable) by physics? What else is there to influence the brain processes but physical laws, previous brain states and external input?

This is the guts of the argument, and to establish free will, given physicalism, requires that the process of choice be explained in terms of brain processes. And I've never seen that qdequately explained, so that is why I can understand why people disbelieve in free will.

I think you're confusing categories. The fact that our mental processes involve chemical reactions seems quite irrelevant to me. Can you prove that one particular chemical reaction will necessarily result in one specific course of action every time, with no possibility of alternative actions?

As I said before, I am not saying this, I'm simply reporting my understanding of what physicalists say (and I've read a bit of their stuff.

But here, I think you are confusing predictability with freedom. I think a neuroscientist can very well predict how a particular chemical reaction will go, the only difficulty is not in principle (they would say), but in practice, because there are too many reactions and connections to enable prediction of choices (in many cases). So they would say the brain processes are determined but too complex to be predictable in practice.

How are you defining 'dualistic'?

For the purposes of this discussion, I think it means that humans cannot be fully explained by physicalist explanations.

I believe the human capacity to make wilfully irrational decisions without any reference to self interest or external stimulus is evidence of free will.

I agree completely. But I don't think physicalism can explain that. Which is one of the reasons why I think physicalism/naturalism is a false idea.

So I can quite understand why people doubt freewill if they are naturalists, and I can't understand how a naturalist can be other than a determinist.

[Mike D]

So if one is a naturalist, it seems to me that one must logically hold that free will is an illusion, and it would require some ingenuity to find a place for free choice.

I believe the solution entails a goodly portion of hand-waving and the magic words 'quantum indeterminacy'... ;D

[bvgdez]

Oct 30, 2012 13:43:37 GMT Mike D said:

So if one is a naturalist, it seems to me that one must logically hold that free will is an illusion, and it would require some ingenuity to find a place for free choice.

I believe the solution entails a goodly portion of hand-waving and the magic words 'quantum indeterminacy'... ;D

That would only leave room for randomness but not for free will, wouldn't it?

I find myself in complete agreement with UnkleE on this even though I'm tending more and more towards naturalism. Having said that there are aslo quite a lot of theists who reject dualism. I can't see how that could work out either except with "a goodly portion of hand-waving and the magic words 'quantum indeterminacy'".

[unkleE]

Oct 30, 2012 14:36:43 GMT bvgdez said:

I find myself in complete agreement with UnkleE on this even though I'm tending more and more towards naturalism. Having said that there are aslo quite a lot of theists who reject dualism. I can't see how that could work out either except with "a goodly portion of hand-waving and the magic words 'quantum indeterminacy'".

I think dualism works with a certain amount of assumption that God made us that way (i.e. with free will). That's not very scientific, and I don't know how he did it, but it is consistent both with christian belief and our shared human experience (IMO).

[bvgdez]

As usual I managed to express mysel unclearly. When I said "I can't think how that would work out" "that" was referring not to dualism but the rejection of dualism by some theists, i.e. I can't see how free will is possible without some form of dualism.

For the sake of my sanity I therefore have to at least leave open the possibility that there might be something in deism or theism. The only alternative, as I see it, is determinism.

[unkleE]

Oct 31, 2012 14:32:45 GMT bvgdez said:

For the sake of my sanity I therefore have to at least leave open the possibility that there might be something in deism or theism. The only alternative, as I see it, is determinism.

We are agreed then - except that I think, for this and other reasons, that theism is almost certainly true.

Why do you think it is only a slight possibility?

[ignorantianescia]

If this reinterpretation of the readiness potential holds, you have to feel bad for the people who had acquired this patent less than a year before Schurger et al.

[sankari]

Oct 30, 2012 8:03:11 GMT unkleE said:

I am not arguing that free will doesn't exist, I am thinking about your original comment about not understanding why people don't believe in free will, and discussing how I think naturalism or physicalism implies determinism.

I see.

Of course you have the capacity to consider multiple causes of action, but can you really choose one or another quite freely, or does it just seem that way?

Yes I can choose. Where's your evidence that I can't?

As I understand things, a neuroscientist who was a physicalist would say that there is no "you" to make any choices apart from your brain. So making a choice has to be explained in terms of the fairly well understood processes of the brain. Those processes are determined by physical laws, previous brain states and external input. So how can "you" choose when "you" are merely the processes that are fully explicable (and in principle predictable) by physics?

Whether the 'you' is something distinct from the brain, a product of the brain, or merely the brain itself, we're still left with an identifiable locus for decision making. Determinists seem to believe the relationship between the 'you' and the chemical processes of brain activity is a one-way street. But why can't we say that it's the 'you' which determines some of the processes?

In any case, the fact that the processes involved are 'fully explicable (and in principle predictable) by physics' is neither here nor there. It certainly does not preclude free will.

What else is there to influence the brain processes but physical laws, previous brain states and external input?

Let's say 'nothing.' Now how does this preclude free will?

This is the guts of the argument, and to establish free will, given physicalism, requires that the process of choice be explained in terms of brain processes. And I've never seen that qdequately explained, so that is why I can understand why people disbelieve in free will.

I don't believe 'lack of adequate explanation' is a strong case against free will.

But here, I think you are confusing predictability with freedom.

No, I'm saying freedom is proved by lack of predictability.

I think a neuroscientist can very well predict how a particular chemical reaction will go, the only difficulty is not in principle (they would say), but in practice, because there are too many reactions and connections to enable prediction of choices (in many cases). So they would say the brain processes are determined but too complex to be predictable in practice.

I think a neuroscientist can make reliable predictions about chemical reactions, but I think he also realises he cannot make reliable predictions about the results of those reactions. However, I think he would say that lack of predictability does not prove free will, and I think he would be right.

[ignorantianescia]

Nov 2, 2012 2:55:31 GMT sankari said:

No, I'm saying freedom is proved by lack of predictability.

? Do you argue that randomness in results of mental processes, leading to unpredictability, indicates free will?