Friday, January 17, 2014

Did Benjamin Libet's experiments show that free will is an illusion?

Materialists such as Jerry Coyne often invoke the experiments of Benjamin Libet when they deny free will. Libet was a neuroscientist at the University of San Francisco during the latter half of the 20th century who did pioneering research on the neurobiology of consciousness.

Specifically, Libet was interested in the correspondence of electrical signals from the brain (measured by electrodes taped to the intact scalp in awake volunteers) and the contents of consciousness. His most famous experiments involve measuring electrical activity in the brain when volunteers were asked to move their wrist. The volunteer would look at a moving clock and note the exact time (to the millisecond) that he consciously decided to move his wrist. Libet compared the timing of the brain activity with the timing of the volunteer's decision to move. He consistently found that the brain activity (he called it the readiness potential) preceded the conscious awareness of a decision to move by a couple hundred milliseconds. The timing typically went like this:

Readiness potential... 400 milliseconds... awareness of intent to move... 200 milliseconds... move wrist.

Other researchers have repeated Libet's experiments, with similar results, and recently researchers have used fMRI to carry out Libet-like experiments. The fMRI studies show that there are often brain activations that precede the conscious decision by several seconds.

Free will-deniers like Coyne have cited Libet's experiments as scientific evidence that free will is an illusion, and that "voluntary" decisions are really generated by electrochemical processes in the brain, without our consent of knowledge. Our sense of free will is an illusion- a post-hoc belief imposed by our brain, which is really making the "decisions".

Coyne:
The experiments show, then, that not only are decisions made before we’re conscious of having made them, but that the brain imagery can predict what decision will be made with substantial accuracy. This has obvious implications for the notion of “free will,” at least as most people conceive of that concept. We like to think that our conscious selves make decisions, but in fact the choices appear to have been made by our brains before we’re aware of them. The implication, of course, is that deterministic forces beyond are conscious control are involved in our “decisions”, i.e. that free will isn’t really “free”. Physical and biological determinism rules, and we can’t override those forces simply by some ghost called “will.” We really don’t make choices—they are made long before we’re conscious of having chosen strawberry versus pistachio ice cream at the store.
Coyne and his materialist allies couldn't be more wrong.

Libet himself was a strong defender of free will, and he interpreted his own experiments as validating free will. He noted that his subjects often vetoed the unconscious "decision" after the readiness potential appeared.

Do we have free will?




I have taken an experimental approach to this question. Freely voluntary acts are preceded by a specific electrical change in the brain (the ‘readiness potential’, RP) that begins 550 ms before the act. Human subjects became aware of intention to act 350–400 ms after RP starts, but 200 ms. before the motor act. The volitional process is therefore initiated unconsciously. But the conscious function could still control the outcome; it can veto the act. Free will is therefore not excluded. These findings put constraints on views of how free will may operate; it would not initiate a voluntary act

but it could control performance of the act. The findings also affect views of guilt and responsibility.


But the deeper question still remains: Are freely voluntary acts subject to macro-deterministic laws or can they appear without such constraints, non-determined by natural laws and ‘truly free’? I shall present an experimentalist view about these fundamental philosophical opposites...
Potentially available to the conscious function is the possibility of stopping or
vetoing the final progress of the volitional process, so that no actual muscle action ensues.
Conscious-will could thus affect the outcome of the volitional process even
though the latter was initiated by unconscious cerebral processes. Conscious-will
might block or veto the process, so that no act occurs. 
The existence of a veto possibility is not in doubt. The subjects in our experiments
at times reported that a conscious wish or urge to act appeared but that they sup-
pressed or vetoed that. In the absence of the muscle’s electrical signal when being
activated, there was no trigger to initiate the computer ’s recording of any RP that may
have preceded the veto; thus, there were no recorded RPs with a vetoed intention to
act. We were, however, able to show that subjects could veto an act planned for per-
formance at a pre-arranged time. They were able to exert the veto within the interval
of 100 to 200 msec. before the pre-set time to act (Libet et al., 1983b). A large RP pre-
ceded the veto, signifying that the subject was indeed preparing to act, even though
the action was aborted by the subject...
The role of conscious free will would be, then, not to initiate a voluntary act, but
rather to control whether the act takes place. We may view the unconscious initiatives
for voluntary actions as ‘bubbling up’ in the brain. The conscious-will then selects
which of these initiatives may go forward to an action or which ones to veto and abort,
with no act appearing.
Libet even observed that his experimental confirmation of free will accorded with the traditional religious understanding of free will:
This kind of role for free will is actually in accord with religious and ethical stric-
tures. These commonly advocate that you ‘control yourself ’. Most of the Ten Com-
mandments are ‘do not’ orders.
How do our findings relate to the questions of when one may be regarded as guilty
or sinful, in various religious and philosophical systems. If one experiences a con-
scious wish or urge to perform a socially unacceptable act, should that be regarded as
a sinful event even if the urge has been vetoed and no act has occurred? Some relig-
ious systems answer ‘yes’... But any such urges would be initiated and developed in
the brain unconsciously, according to our findings. The mere appearance of an inten-
tion to act could not be controlled consciously; only its final consummation in a motor
act could be consciously controlled. Therefore, a religious system that castigates an
individual for simply having a mental intention or impulse to do something unaccept-
able, even when this is not acted out, would create a physiologically insurmountable
moral and psychological difficulty... 
Indeed, insistence on regarding an unacceptable urge to act as sinful, even when no
act ensues, would make virtually all individuals sinners. In that sense such a view
could provide a physiological basis for ‘original sin’!
Libet concludes:
My conclusion about free will, one genuinely free in the non-determined sense, is
then that its existence is at least as good, if not a better, scientific option than is its
denial by determinist theory. Given the speculative nature of both determinist and
non-determinist theories, why not adopt the view that we do have free will (until some
real contradictory evidence may appear, if it ever does). Such a view would at least
allow us to proceed in a way that accepts and accommodates our own deep feeling
that we do have free will. We would not need to view ourselves as machines that act in
a manner completely controlled by the known physical laws.

Coyne and his allies misrepresent Libet's findings. Libet concluded from his experiments that we do have free will-- the ability to veto pre-conscious intentions-- and he noted that the veto appeared to be freely chosen, without any neurophysiological evidence for neurophysiological determinism.

Libet's finding that there appear to be pre-conscious intentions that sometimes precede conscious intentions is unsurprising. We experience such intentions constantly. We walk from place to place without consciously thinking of the intricate details of the walk-- the path, the coordination of muscles, etc. We often get where we're going with remarkably little conscious attention to the process-- think of how often you drive home from work without consciously thinking much about the route, or even about other cars, traffic signals, etc. When we type, as I am doing now to write this post, we typically don't think about the individual motion of our fingers. In fact, performing a skillful act like typing or playing a musical instrument or driving requires that our actions be automatic and unconscious. That doesn't mean that our typing or walking or driving is not freely chosen. It means that much of our deliberate behavior is the result of a combination of a free choice to act and an elaborate preconscious and unconscious system of intentions that enable the freely chosen act to happen efficiently.

Libet proposes (based on his work) a common-sense model of free will: our unconscious is a bubbling sea of velleities. We freely choose the impulses we wish to enact by prescinding from a veto, and we freely choose the impulses we wish to suppress by vetoing the act. Libet found experimental traces of the unconscious impulses (the readiness potential) and experimental confirmation of the freely-chosen veto (the conscious choice unaccompanied by corresponding electrophysiological activity). He even noted that his experimental results validated a particular traditional religious understanding of moral choice-- that sin is in the act, which is freely chosen, not in the temptation, which can arise without our choice. He even proposed a neurophysiological model of original sin!

You may ask, at this point: why do Coyne and his materialist allies utterly misrepresent Libet's experiments? Why would materialists cite the work of a researcher who scientifically confirmed free will, and even confirmed the traditional religious view of culpability for sin? Why would materialists cite experiments that confirm the opposite of their claims? Perhaps materialists don't understand the science, or perhaps they never bothered to try.

Whatever their reason for misrepresenting Libet's work, materialists' invocation of research that validates free will is likely a consequence not of their acquaintance with the science itself (Coyne seems blissfully unaware of Libet's actual experiments and conclusions), but a consequence of the metaphysical biases that materialists bring to the issue. You can see the same metaphysical bias and denial of the plain implications of the science in their denial of teleology in evolutionary biology.

For materialists, it's metaphysics first, and evidence later, if at all. 

30 comments:

  1. 'But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell' (KJV Matthew 5:28-9)

    Yeah, right... Libet's work 'validated a particular traditional religious understanding of moral choice - that sin is in the act, which is freely chosen, not in the temptation, which can arise without our choice'.

    Only if you pick and choose which parts of Scripture to accept or ignore.

    And anyway. The materialist position is that there's 'free won't', but not 'free will', which involves making conscious uncaused decisions. Conscious uncaused decisions don't happen because everything has a 'cause', even if we aren't aware of them consciously.

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    Replies
    1. Egnor,

      'Free will' is conscious uncaused decisions. Doesn't happen. No decision is uncaused.

      'Free won't' is conscious caused decisions. Obviously occurs. Decisions do have causes.

      'Conscious caused decisions' obviously isn't the same as 'conscious uncaused decisions'.

      Delete
    2. Adm. G Boggs, Glenbeckistan NavyJanuary 17, 2014 at 10:05 AM

      blankfield: "The materialist position is that there's 'free won't', but not 'free will'..."

      Have you thought through the implications of that position vis-a-vis operant conditioning?

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    3. Senile old fart,

      And your point, if any?

      Delete
  2. "Indeed, insistence on regarding an unacceptable urge to act as sinful, even when no act ensues, would make virtually all individuals sinners. In that sense such a view could provide a physiological basis for ‘original sin’!"

    Wow, really interesting. Dr. Egnor, this is a great post.

    "a religious system that castigates an
    individual for simply having a mental intention or impulse to do something unacceptable, even when this is not acted out, would create a physiologically insurmountable moral and psychological difficulty"


    Yes, and no. Obviously one cannot be blamed for an impulse. On the other hand, one of the principles of cognitive behavior therapy (the treatment of choice for most emotional disorders) is that we can have conscious control over our automatic thoughts and interpretations, and can be taught to reinterpret stimuli in such a way as to avoid anxiety, distress, etc.

    In Eastern Christianity, there is a tradition of "mastering/guarding the intellect" which surprisingly anticipates many of the tenets of CBT.

    - C

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  3. Adm. G Boggs, Glenbeckistan NavyJanuary 17, 2014 at 9:43 AM

    In the first place, it's absurd to draw conclusions about free will and complex moral behaviors from reaction time data. That is perhaps the non plus ultra of ridiculous reductionism, like measuring reading ability using a tachistoscopic letter recognition task.

    The whole point of the free will debate is the issue of self-control; i.e., can we, as organisms, control our own behaviors? Or, as in Coyne's example, is the choice of strawberry over pistachio ice cream - or no ice cream! - merely an inevitable outcome of a deterministic process?

    After all, there would be no point in castigating and haranguing the obese, criminals, pedophiles, televangelists, or swindlers if they truly have no self-control and their behaviors are determined. If we cannot control our own behavior, the only way to increase the Collective General Happiness would be to institute broad social surveillance and finely tuned regulatory webs backed up by swift and sure administrations of positive reinforcements, negative reinforcements, and punishments.

    So it's obvious that the existence or non-existence of self-control has major political implications.

    The best research program on self-control that I have seen is the work conducted by Roy Baumeister and his students. That work suggests that individuals do exhibit greater or lesser self-control and the engine of that self-control is willpower. It appears that individuals with greater self-control tend to be more successful (as measured by several social indicia), less likely to be incarcerated, exhibit fewer appetitive "binge" behaviors, are less likely to complain of psychological disorders, enjoy better interpersonal relationships, are healthier, and even tend to live longer.

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  4. It’s impossible for any of us to be aware of the events and processes in our brains that result in our decisions, actions, and impulses. I have no problem with the ambiguity of knowing that these processes take place while simultaneously believing that I have free will. If you want to make the argument that free will is an illusion fine, I get it, but that doesn’t change the fact that for most of us it’s such a powerful illusion that we have no choice but to act with our perceived free will and get on with our day.

    So Doctor, How does the soul work? Does the soul require a physical substrate to operate, sort of like software on a computer? Are the actions of the soul caused by any mechanisms or processes? Is the functioning of the soul governed by any physical law? If the answer to any of these questions is anything other than “its pure fucking magic” I really don’t see how the soul can be that much different than the brain anyway.

    -KW

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    Replies
    1. I understand the soul in the hylemorphic sense, which is the way it was originally explained by Aristotle, expanded upon by Aquinas, and is still understood in Catholic theology (and in Eastern Orthodox traditions).

      The soul is the substantial form of the body, in much the same way that the form of "chair" is the substantial form of a chair. It's not separable from the body under ordinary circumstances: it forms a composite with prime matter to make the person, which is the lowest level of existential reduction.

      In Thomist terms, the soul is the intelligible principle of the body. It is not a wispy translucent thing (like Patrick Swayze in "Ghost"). It is the intelligible principle by which the body is what it is. The soul includes vegetative functions, locomotion and sensation, and higher rational faculties.

      The soul exerts changes on the body efficiently (by directly causing a muscle to move, etc), formally (by forming an idea to be achieved) and finally (by providing a goal for the change).

      The hylemorphic tradition has a quite detailed understanding of the soul, and I find it to be far more satisfactory than mechanical explanations, which are fraught will all manner of confusion and contradiction.

      Delete
    2. One of hylomorphic dualism's admitted weaknesses is that provides poor fodder for supernatural Hollywood love stories. This summer, Patrick Swayze's soul is... the form of his body!

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    3. Indeed, although ironically hylemorphic dualism specifically denies that the soul is a substance in itself. It is a subsistent form, capable of independence from the body only in a very attenuated way transiently after death.

      It has no corporeal existence, and can't "appear" to people, and looks nothing like Patrick Swayze.

      Delete
    4. Indeed, although ironically hylemorphic dualism specifically denies that the soul is a substance in itself. It is a subsistent form, capable of independence from the body only in a very attenuated way transiently after death.

      And your evidence for this? It sounds about as sophisticated as the view that the world consists of the four elements water, fire, earth and air.

      Delete
    5. It's a metaphysical assertion, not a scientific theory, so the "evidence" is rational, based on the explanatory power of hylemorphism, which is considerable.

      I point out that the metaphysical basis of Mechanical Philosophy, of which you are a victim, is just dumbed-down hylemorphism, with formal and final causes ignored, and truncated material and efficient causes invoked.

      Notably, the "mind-body problem" didn't exist for the Scholastics, because the hylemorphic understand of the soul/mind is elegant and highly satisfactory. It was only with the rejection of scholasticism-- most notably by Descartes with his substance dualism-- that the mind-body relationship became a problem.

      Ironically, Mechanical Philosophy causes problems, rather than solving them.

      Delete
    6. Hylemorphic dualism, what rubbish. Of all the “ancient wisdom” you pedal as truth, this sounds the most like a couple of intelligent but ignorant ancients pulling shit out of their ass. I guess you've got to start somewhere, but to think our understanding of the world's nature and various existential issues essentially peaked early in our intellectual history is crazy. The early philosophers and men of science that we all admire are some of the most prominent giants on who's shoulders we stand, but there near the bottom of the heap.

      “The hylemorphic tradition has a quite detailed understanding of the soul, and I find it to be far more satisfactory than mechanical explanations, which are fraught will all manner of confusion and contradiction. “

      That is a truly astonishing thing for a brain surgeon to say. Sorry but you are the last brain surgeon I would want to go near my head with a knife.

      -KW

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    7. KW,

      Surgeons are little more than technicians, performing operations in a proven standardised fashion. I wouldn't have too much in the way of concern with Egnor operating on me or a relative - provided it's a procedure he's qualified to do.

      My only concern would be Egnor's age and judgement. He's approaching 59, and most surgeons are best in the late 40s - they have the knowledge, experience and manual dexterity then. Knowledge and dexterity often lessens after then.

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    8. That's a real rational thing to say, KW. You make life-and-death decisions based on an opinion about metaphysics expressed on a blog.

      How then can we trust your science, if you'd even stake your life on metaphysical-correctness?

      You're an irrational ideologue to the bone. If you ever need emergency brain surgery, make sure you ask the surgeon about Aquinas and Descartes before they wheel you into the OR.

      Delete
    9. It's a metaphysical assertion, not a scientific theory, so the "evidence" is rational, based on the explanatory power of hylemorphism, which is considerable.

      Right. So no evidence then for the claim that the 'soul' is

      capable of independence from the body only in a very attenuated way transiently after death.

      You just made that up - or, more accurately, you just copied that nonsense from your 'spiritual leaders'.

      Give an example of something that hylemorphism can explain that science can't explain, in a way that can be confirmed by evidence.


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    10. bach:

      I'm not the man I used to be. But I never was the man I used to be.

      Delete
    11. [Give an example of something that hylemorphism can explain that science can't explain, in a way that can be confirmed by evidence.]

      You mean materialism, not "science".

      Hylemorphism can explain collapse of the waveform in quantum mechanics-- the reduction of potency to act-- a fact that was pointed out by Heisenberg, who had strong sympathies for hylemorphism.

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    12. How does hylemorphism explain "collapse of the waveform"? I don't expect you to understand QM, so why not offer an example of something you do understand? A verifiable prediction would be nice, something science would not be able to predict.

      Delete
    13. Troy,

      Egnor doesn't do predictions. He does postdictions. He thinks that anything that explains an event after the fact is valid. He goes in for story telling and not valid testable hypothesis generation.

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    14. Hylemorphism is an explanation of reality. So is materialism. What predictions does materialism make?

      Likely answer - "That metabolic activity in the brain will correlate with mental activity, and damage to the brain will result in thought impairment"

      The hylemoprhist would expect the same result, given the soul-body unity. Neuroscientist Walter J. Freeman, with no theological axe to grind, acknowledged the surprising unity between Aquinas' understanding of the soul and what we now know about the brain.

      Can materialism explain intentionality (about-ness) in mental activity? No. Hylomorphic dualism can. There's one leg up.

      Can materialism account for true knowledge? No. Hylomorphic dualism can. There's another.

      - Curio

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    15. And can someone settle once and for all whether it's hylemorphic or hylomorphic? Any Greek grammarians out there?

      - Curio

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    16. Curio:

      Can materialism explain intentionality (about-ness) in mental activity? No. Hylomorphic dualism can. There's one leg up.

      That's like saying the Flying Spaghetti Monster has inserted an invisible intentionality noodle in people's brains. There is no way to verify or falsify it.

      That's what hylemorphism boils down to: postulating undetectable entities with fancy names that magically explain whatever needs explaining.

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    17. "postulating undetectable entities with fancy names that magically explain whatever needs explaining."

      Memes, natural selection, sexual selection, disruptive selection, stabilizing selection, directional selection, purifying selection, diversifying selection, punctuated equilibrium, neutral drift, balancing selection, convergent evolution, Cope's rule, eugenics, group selection, adaptive radiation, yada, yada...

      Delete
    18. [And can someone settle once and for all whether it's hylemorphic or hylomorphic? Any Greek grammarians out there?]

      I've seen it both ways. Hyle seems more cultured and refined :)
      It's probably like potato and potatoe-- it doesn't matter unless you're Dan Quale.

      Delete
    19. And can someone settle once and for all whether it's hylemorphic or hylomorphic? Any Greek grammarians out there?

      Greek compounds with ὕλη 'wood, forest' as the first member in most cases use the compositional form ὑλο-, as in ὑλοτόμος 'woodcutter' and ὑλοσκόπος'forest ranger' (though analogical variants with ὕλη- occur occasionally). Aristotle would have used ὑλόμορφος (hulómorphos) if the word were Ancient Greek, which of course it isn't; it was coined in the 19th century.

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    20. dziękuję Professor Gąsiorowski!

      Didn't expect to have a real expert in our midst, though I could have guessed if I had read your blog.

      Troy - there aren't any noodly appendages in hylemorphic theory. Intentionality means "aboutness". Matter, all matter, lacks this quality. Rocks aren't about swans, aggregates of neurons aren't about linguistic theory. Our thoughts, on the other hand, have the ability to be about other things.

      - Curio

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    21. Curio:

      Intentionality means "aboutness". Matter, all matter, lacks this quality. Rocks aren't about swans, aggregates of neurons aren't about linguistic theory. Our thoughts, on the other hand, have the ability to be about other things.

      What makes you think that matter lacks this quality? It's your material brain that's what! But seriously, you seem to be very sure that matter can't have thoughts. I didn't realize that question had been settled already. When John von Neumann was asked, after one of his lectures, "but surely you don't believe that machines can think?", he replied - and I paraphrase: "if you tell me exactly what thinking is, I can make a machine that can do just that!"

      Hylemorphic theory is untestable gobbledygook invented by theologians lacking a subject.

      Delete
  5. I would only add that its the memory at work wjen we drive, type, walk about.
    Its not a mysterious acting of the will all the way but simply the will says GET ME THERE and the memory takes over. Just like speech reflects thoughts but is only a memory of how to use sounds in segregated combinations to reflect the thoughts.
    How could a mere mechanism that translates thoughts to the brain to the body HAVE a mind of its own.
    The evolutionists missed on this .

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