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io9 we come from the future
Scientific evidence that you probably don’t have free will
George Dvorsky
Humans have debated the issue of free will for millennia. But over the
past several years, while the philosophers continue to argue about the
metaphysical underpinnings of human choice, an increasing number of
neuroscientists have started to tackle the issue head on — quite literally. And
some of
them believe that their experiments reveal that our subjective experience of
freedom may be nothing more than an illusion. Here's why you probably
don't have free will.
Indeed, historically speaking, philosophers have had plenty to say on the
matter. Their ruminations have given rise to such considerations as
cosmological determinism (the notion that everything proceeds over the course
of
time in a predictable way, making free will impossible), indeterminism (the
idea that the universe and our actions within it are random, also making
free will impossible), and cosmological libertarianism/compatibilism (the
suggestion that free will is logically compatible with deterministic views of
the universe).
Now, while these lines of inquiry are clearly important, one cannot help
but feel that they're also terribly unhelpful and inadequate. What the debate
needs is some actual science — something a bit more...testable.
And indeed, this is starting to happen. As the early results of scientific
brain experiments are showing, our minds appear to be making decisions
before we're actually aware of them — and at times by a significant degree.
It's a disturbing observation that has led some neuroscientists to conclude
that we're less in control of our choices than we think — at least as far as
some basic movements and tasks are concerned.
At the same time, however, not everyone is convinced. It may be a while
before we can truly prove that free will is an illusion.
Bereitschaftspotential
Neuroscientists first became aware that something curious was going on in
the brain back in the mid 1960s.
German scientists _Hans Helmut Kornhuber and Lüder Deecke discovered a
phenomenon_
(http://www.sciencedirect.com/science/article/pii/S1567424X09701588) they
dubbed "_bereitschaftspotential_
(http://www.ncbi.nlm.nih.gov/pubmed/16876476) " (BP) — a term that translates
to "readiness potential." Their
discovery, that the brain enters into a special state immediately prior to
conscious awareness, set off an entirely new subfield.
After asking their subjects to move their fingers (what were self-initiated
movements), Kornhuber and Deecke's electroencephalogram (EEG) scans showed
a slow negative potential shift in the activity of the motor cortex just
slightly prior to the voluntary movement. They had no choice but to conclude
that the unconscious mind was initiating a freely voluntary act — a wholly
unexpected and counterintuitive observation.
Needless to say it was a discovery that greatly upset the scientific
community who, since the days of Freud, had (mostly) adopted a strictly
deterministic view of human decision making. Most scientists casually ignored
it.
But subsequent experiments by Benjamin Libet in the 1980s reinforced the
pioneering work of Kornhuber and Deecke. Similarly, Libet had his
participants move their fingers, but this time while watching a clock with a
dot
circling around it. His data showed that the readiness potential started about
0.35 seconds earlier than participants' reported conscious awareness.
He concluded that _we have no free will as far as the initiation of our
movements are concerned_
(http://journals.cambridge.org/action/displayAbstract;jsessionid=84922D40CA4B0B979EC260B96667BC32.journals?fromPage=online&aid=671
1468) , but that we had a kind of cognitive "veto" to prevent the movement
at the last moment; we can't start it, but we can stop it.
>From a neurological perspective, Libet and others attributed the effect to
the SMA/pre-SMA and the anterior cingulate motor areas of the brain — an
area that allows us to focus on self-initiated actions and execute
self-instigated movements.
Modern tools show the same thing
More recently, neuroscientists have used more advanced technologies to
study this phenomenon, namely fMRIs and implanted electrodes. But if anything,
these new experiments show the BP effect is even more pronounced than
previously thought.
For example, _a study by John-Dylan Haynes in 2008_
(http://www.nature.com/neuro/journal/v11/n5/full/nn.2112.html) showed a
similar effect to the one
revealed by Libet. After putting participants into an fMRI scanner, he
told them to press a button with either their right or left index fingers at
their leisure, but that they had to remember the letter that was showing on
the screen at the precise moment they were committed to their movement.
The results were shocking. Haynes's data showed that the BP occurred one
entire second prior to conscious awareness — and at other times as much as
ten seconds. Following the publication of his paper, _he told_
(http://www.nature.com/news/2011/110831/full/477023a.html) Nature News:
The first thought we had was 'we have to check if this is real.' We came up
with more sanity checks than I've ever seen in any other study before.
The cognitive delay, he argued, was likely due to the operation of a
network of high-level control areas that were preparing for an upcoming
decision
long before it entered into conscious awareness. Basically, the brain
starts to unconsciously churn in preparation of a decision, and once a set of
conditions are met, awareness kicks in, and the movement is made.
In another study, neuroscientist Itzhak Fried put aside the fMRI scanner in
favor of digging directly into the brain (so to speak). To that end, he
_implanted electrodes into the brains of participants_
(http://www.cell.com/neuron/retrieve/pii/S0896627310010822) in order to record
the status of
individual neurons — a procedure that gave him an incredibly precise sense of
what was going on inside the brain as decisions were being made.
His experiment showed that the neurons lit up with activity as much as 1.5
seconds before the participant made a conscious decision to press a button.
And with about 700 milliseconds to go, Fried and his team could predict
the timing of decisions with nearly 80% accuracy. In some scenarios, he had
as much as 90% predictive accuracy.
Different experiment, similar result.
Fried surmised that volition arises after a change in internally generated
fire rates of neuronal assemblies cross a threshold — and that the medial
frontal cortex can signal these decisions before a person is aware of them.
"At some point, things that are predetermined are admitted into
consciousness," he _told_
(http://www.nature.com/news/2011/110831/full/477023a.html)
Nature, suggesting that the conscious will might be added on to a decision
at a later stage.
And in yet another study, this one by Stefan Bode, _his detailed fMRI
experiments_
(http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021612) showed
that it was possible to actually decode the outcome of free
decisions for several seconds prior to it reaching conscious awareness.
Specifically, he discovered that activity patterns in the anterior
frontopolar cortex (BA 10) were temporally the first to carry information
related
to decision-making, thus making it a prime candidate region for the
unconscious generation of free decisions. His study put much of the concern
about
the integrity of previous experiments to rest.
The critics
But not everyone agrees with the conclusions of these findings. Free will,
the skeptics argue, is far from debunked.
Back in 2010, _W. R. Klemm published an analysis_
(http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2942748/) in which he complained
about the ways in
which the data was being interpreted, and what he saw as grossly
oversimplified experimentation.
Others have _criticized the timing judgements_
(http://www.ncbi.nlm.nih.gov/pubmed/17214565) , arguing about the short
timeframes between action and
movement, and how attention to aspects of timing were likely creating
distortions in the data.
It's also possible that the brain regions being studied, namely the
pre-SMA/SMA and the anterior cingulate motor areas of the brain, _may only be
responsible for the late stages of motor planning_
(http://www.sciencemag.org/content/318/5850/594.abstract) ; it's conceivable
that other higher brain
systems might be better candidates for exerting will.
Also, test subjects — because of the way the experiments were set up — may
have been influenced by other "choice-predictive" signals; the researchers
may have been measuring brain activity not directly related to the
experiment itself.
The jury, it would appear, is still out on the question of free will. While
the neuroscientists are clearly revealing some important insights into
human thinking and decision making, more work needs to be done to make it more
convincing.
What would really settle the issue would be the ability for neuroscientists
to predict the actual outcome of more complex decisions prior to the
subject being aware of it themselves. That would, in a very true sense, prove
that free will is indeed an illusion.
Furthermore, neuroscientists also need to delineate between different types
of decision-making. Not all decisions are the same; moving a finger or
pressing a button is very different than contemplating the meaning of life, or
preparing the words for a big speech. Given the limited nature of the
experiments to date (which are focused on volitional physical movements), this
would certainly represent a fruitful area for inquiry.
Blurring science, philosophy, and morality
Moreover, there's also the whole issue of how we're supposed to reconcile
these findings with our day-to-day lives. Assuming we don't have free will,
what does that say about the human condition? And what about taking
responsibility for our actions?
Daniel Dennett has recently tried to rescue free will from the dustbin of
history, saying that there's still some elbow room for human agency — and
that these are still scientific questions. Dennett, acknowledging that free
will in the classic sense is largely impossible, has attempted to reframe
the issue in such a way that free will can still be shown to exist, albeit
under certain circumstances. He _writes_
(http://edge.org/conversation/normal-well-tempered-mind) :
There's still a lot of naïve thinking by scientists about free will. I've
been talking about it quite a lot, and I do my best to undo some bad
thinking by various scientists. I've had some modest success, but there's a
lot
more that has to be done on that front. I think it's very attractive to
scientists to think that here's this several-millennia-old philosophical idea,
free will, and they can just hit it out of the ballpark, which I'm sure
would be nice if it was true.
It's just not true. I think they're well intentioned. They're trying to
clarify, but they're really missing a lot of important points. I want a
naturalistic theory of human beings and free will and moral responsibility as
much as anybody there, but I think you've got to think through the issues a
lot better than they've done, and this, happily, shows that there's some real
work for philosophers.
Dennett, who is mostly responding to _Sam Harris_
(http://www.samharris.org/blog/item/life-without-free-will) , has come under
criticism from people
who complain that he's being epistemological rather than scientific.
Indeed, Sam Harris _has made a compelling case that we don't have it, but
that it's not a problem. Moreover, he argues that the ongoing belief in
free will needs to come to an end_
(http://www.amazon.com/gp/product/1451683405?ie=UTF8&tag=io9amzn-20&linkCode=xm2&camp=1789&creativeASIN=1451683405)
:
A person's conscious thoughts, intentions, and efforts at every moment are
preceded by causes of which he is unaware. What is more, they are preceded
by deep causes — genes, childhood experience, etc. — for which no one,
however evil, can be held responsible. Our ignorance of both sets of facts
gives rise to moral illusions. And yet many people worry that it is necessary
to believe in free will, especially in the process of raising children.
Harris doesn't believe that the illusoriness of free will is an "ugly
truth," nor something that will forever be relegated to philosophical
abstractions. This is science, he says, and it's something we need to come to
grips
with. "Recognizing that my conscious mind is always downstream from the
underlying causes of my thoughts, intentions, and actions does not change the
fact that thoughts, intentions, and actions of all kinds are necessary for
living a happy life — or an unhappy one, for that matter," he writes.
But as Dennett correctly points out, this is an issue that's far from being
an open-and-shut case. Advocates of the "free will as illusion"
perspective are still going to have to improve upon their experimental
methods, while
also addressing the work of philosophers, evolutionary biologists — and
even quantum physicists.
Why, for example, did humans evolve consciousness instead of zombie-brains
if consciousness is not a channel for exerting free will? And given the
nature of quantum indeterminacy, what does it mean to live in a universe of
fuzzy probability?
There's clearly lots of work that still needs to be done.
--
Centroids: The Center of the Radical Centrist Community
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