New intepretation of Libet's experiment

[sbu]

Thought this article might be of interest:

Brain might not stand in the way of free will - life - 06 August 2012 - New Scientist

...."Libet argued that our brain has already decided to move well before we have a conscious intention to move," says Schurger. "We argue that what looks like a pre-conscious decision process may not in fact reflect a decision at all. It only looks that way because of the nature of spontaneous brain activity."

So what does this say about free will? "If we are correct, then the Libet experiment does not count as evidence against the possibility of conscious will," says Schurger.
.....

[Open Mind]

Thanks for another interesting piece of news SBU, keep it going

...."Libet argued that our brain has already decided to move well before we have a conscious intention to move," says Schurger. "

Let us not blame Libet too much, it is more a case political materialists jumped upon these experiments as if Libet supported their viewpoint, Libet was far more open to interpretation ... .


'...Believers in physicalism are confident that completely adequate correlations will eventually be discovered, but that remains a theoretical belief. There is some evidence that a full correlation may not occur; i.e. there may be conscious mental events that appear to occur not tied or based upon neural events (Libet, 1994; 1996; 1999) -Benjamin Libet

[sbu]

I think this is very interesting news taking into account how frequent Libet's experiment is referenced as proof against free will.

[Paul C. Anagnostopoulos]

Yikes, what a badly written article. Here is the abstract:

An accumulator model for spontaneous neural activity prior to self-initiated movement

Sounds like a mild imperative to move means that the time of movement is based on "spontaneous subthreshold fluctuations." Are those random? But if I'm ordered to move, then my speed of doing so depends on how much those fluctuations have accumulated.

I'm not sure how free will gets back into the picture, because it doesn't seem as if we can find the "moment of decision" using their model. It might be after the urge to move becomes conscious. As Schurger said (bolding mine):

"We argue that what looks like a pre-conscious decision process may not in fact reflect a decision at all. It only looks that way because of the nature of spontaneous brain activity."

Even if the decision is made once the subject feels the urge to move, that says nothing about whether the decision is free.

Good stuff.

~~ Paul

[Interesting Ian]

Originally Posted by Paul C. Anagnostopoulos

Yikes, what a badly written article. Here is the abstract:

An accumulator model for spontaneous neural activity prior to self-initiated movement

Sounds like a mild imperative to move means that the time of movement is based on "spontaneous subthreshold fluctuations." Are those random? But if I'm ordered to move, then my speed of doing so depends on how much those fluctuations have accumulated.

I'm not sure how free will gets back into the picture, because it doesn't seem as if we can find the "moment of decision" using their model. It might be after the urge to move becomes conscious. As Schurger said (bolding mine):

"We argue that what looks like a pre-conscious decision process may not in fact reflect a decision at all. It only looks that way because of the nature of spontaneous brain activity."

Schurger says

"Libet argued that our brain has already decided to move well before we have a conscious intention to move. We argue that what looks like a pre-conscious decision process may not in fact reflect a decision at all. It only looks that way because of the nature of spontaneous brain activity."

If we are correct, then the Libet experiment does not count as evidence against the possibility of conscious will".

You are asserting he's incorrect?

[David Bailey]

Originally Posted by Paul C. Anagnostopoulos

Yikes, what a badly written article. Here is the abstract:

An accumulator model for spontaneous neural activity prior to self-initiated movement

Sounds like a mild imperative to move means that the time of movement is based on "spontaneous subthreshold fluctuations." Are those random? But if I'm ordered to move, then my speed of doing so depends on how much those fluctuations have accumulated.

Unfortunately, so many NS articles are badly written, that I gave up with that magazine a long time ago

Considering that there are billions of neurons in the brain, I'd imagine a lot of what goes on must be "subthreshold".

David

[Paul C. Anagnostopoulos]

Originally Posted by Interesting Ian

You are asserting he's incorrect?

No, but he hedges his bet anyway: "... may not in fact reflect a decision."

No one should have been arguing that Libet definitively shows the decision is made nonconsciously. After all, how can we distinguish between these two scenarios. The line shows when things become conscious.

Scenario 1:
readiness potential accumulates
decision to act, nonconscious
readiness potential accumulates, perhaps faster
------------------------
urge to act felt
act

Scenario 2:
readiness potential accumulates
readiness potential accumulates
------------------------
urge to act felt = decision to act
act

Of course, prior to both scenarios is the decision to cooperate with the experiment. Otherwise no readiness potential would accumulate at all. Is that decision conscious?

The researchers have added an explicit order to act using the click. That introduces new scenarios, but one of them is this:

Scenario 3:
readiness potential accumulates
decision to act, nonconscious
readiness potential accumulates, perhaps faster
click
------------------------
urge to act felt
act

The original decision to act is still nonconscious.

I think more experiments are needed to tease apart the different steps.

~~ Paul

[Paul C. Anagnostopoulos]

Originally Posted by David Bailey

Considering that there are billions of neurons in the brain, I'd imagine a lot of what goes on must be "subthreshold".

If everything had to be conscious, you couldn't play the piano or do a thousand other things. There is no conscious will involved in pressing the keys.

~~ Paul

[David Bailey]

Originally Posted by Paul C. Anagnostopoulos

If everything had to be conscious, you couldn't play the piano or do a thousand other things. There is no conscious will involved in pressing the keys.

~~ Paul

We are probably talking at cross purposes, I took "subthreshold" to mean the level of neural activity below which it doesn't show on an EEG.

Do you think the difference between non-conscious events and conscious ones is size? Is there any evidence that this is so? I would have thought that visual processing, which is unconscious, must occupy a lot of neurons.

Playing the piano does involve conscious thinking, but ideally not about individual notes. My guess is that this is like almost everything we do - we don't consciously control the balance feedback that keeps us walking, or the details of articulation as we speak.

David

[Paul C. Anagnostopoulos]

Originally Posted by David Bailey

We are probably talking at cross purposes, I took "subthreshold" to mean the level of neural activity below which it doesn't show on an EEG.

Do you think the difference between non-conscious events and conscious ones is size? Is there any evidence that this is so? I would have thought that visual processing, which is unconscious, must occupy a lot of neurons.

I think it's something about the extent of the activation of neuron coalitions and/or the strength of the signals.

Playing the piano does involve conscious thinking, but ideally not about individual notes. My guess is that this is like almost everything we do - we don't consciously control the balance feedback that keeps us walking, or the details of articulation as we speak.

Right.

~~ Paul