Björn Brembs

On our final day ([day
1](https://bjoern.brembs.net/2015/11/chance-in-animate-nature-day-1/),
[day
2](https://bjoern.brembs.net/2015/11/chance-in-animate-nature-day-2/)),
I was only able to hear [Boris
Kotchoubey](https://www.zpid.de/psychauthors/index.php?wahl=forschung&uwahl=psychauthors&uuwahl=p00799BK)'s
(author of "[why are you
free?](https://www.amazon.com/Why-Are-You-Free-Neurobiology/dp/1619425343/ref=sr_1_1?s=books&ie=UTF8&qid=1447318435&sr=1-1)")
talk, as I had to leave early to catch my flight. He made a great effort
to slowly introduce us to nonlinear dynamics and the consequences it has
for the predictive power of science in general.

Applied to human movement in particular, he showed that nervous systems
take advantage of the biophysics of bodily motion to only add the
component to movement, that biophysics (think your leg swinging while
you walk) doesn't already take care of. This is an important and all too
often forgotten insight that I recognize from the work of the laboratory
of [Hillel Chiel](https://biology.case.edu/faculty/hillel-chiel/) in
*Aplysia* biting behavior. He explained work studying hammer blows,
where the trajectory of all arm joints did not seem to follow any common
rules -- the only commonality that could be found between individual
hammer blows was the trajectory of the hammer's head. This is
reminiscent of the distinction between world- and self-learning in
flies, where the animals can use any behavior very flexibly to
accomplish an external goal, until they have performed the behavior
often enough to become habitual, at which time this flexibility is
(partially?) lost.

Halfway through the talk, he arrived at the [uncontrolled manifold
hypothesis](https://en.wikipedia.org/wiki/Motor_coordination#Uncontrolled_manifold_hypothesis),
where the nervous system isn't trying to eliminate noise, but to use it
to its advantage for movement control. Not entirely unexpectedly, he
went from this to
[chemotaxis](https://chemotaxis.biology.utah.edu/Parkinson_Lab/projects/ecolichemotaxis/ecolichemotaxis.html)
in *Escherichia coli* as an example of a process which also takes
advantage of chance.

He differentiates between two different kinds of unpredictable systems:
a) highly complex and incomputable systems b) unique unrepeatable
systems. The differences between these two systems breakdown as soon as
the uncertainly principle is an actual property of the universe that
poses absolute, non-circumventable limits on the potential knowledge
anyone can have about these systems.


On our final day (day 1, day 2), I was only able to hear Boris Kotchoubey‘s (author of “why are you free?“) talk, as I had to leave early to catch my flight. He made a great effort to slowly introduce us to nonlinear dynamics and the consequences it has for the predictive power of science in general.

Chance in animate nature, day 3

To my knowledge, no neuroscientist hypothesizes that there is magic in
our heads. However, it appears this is a hypothesis that flies by the
editors at the [New York
Times](https://www.nytimes.com/2013/06/18/opinion/brooks-beyond-the-brain.html).
The title of this op-ed piece says it all: "beyond the brain". The
author, [David
Brooks](https://topics.nytimes.com/top/opinion/editorialsandoped/oped/columnists/davidbrooks/index.html),
claims: "The brain is not the mind." Last I looked (which was a few
seconds ago, I admit), beyond the brain was the Pia mater, the
subarachnoid space, the Arachnoid, the dura mater and the skull. I
wonder, just where precisely does the magic mind sit, if it's not the
brain? In the subarachnoid space, squeezed between layers of connective
tissue and blood vessels? Or is it even beyond the skull, hovering above
our heads? Now, Mr. Brooks doesn't mention the [Psychokinetic Energy
Meter](https://ghostbusters.wikia.com/wiki/P.K.E._Meter), but he makes
it sound as if in his world this is the scientific instrument with which
one would measure the capacity of the mind to move the body. Probably
most disappointingly, Mr. Brooks bolsters his magic-mind hypothesis with
the classic argument from incredulity: 'I don't understand it, so it
must be magic': "It is probably impossible to look at a map of brain
activity and predict or even understand the emotions, reactions, hopes
and desires of the mind." This is like saying "it's probably impossible
to build a heavier-than-air flying machine" before the Wright brothers'
first flight. More disturbingly, it's like saying: "I don't understand
no evilution, therefore magic man dunnit".

Mr. Brooks caps his magic-mind hypothesis off with a few short
paragraphs essentially saying "we have free will because I think so,
free will is magic, so there's magic in the head -- and science is too
limited to get into magic, don't you forget that!" Given that his main
point is that the mind is magic, one can only assume that he means
neuroscience is too limited to understand free will sort of like
medicine is too limited to understand homeopathy and physics is too
limited to understand astrology. This final point is probably the only
accurate statement of the entire piece: magic in the head is about as
thoroughly debunked as homeopathy or astrology.

What we call 'mind' exists in a similar way as colors exist: our brain
creates it. Colors are real in the sense that our brain makes colors
real, it constructs a reality with colors, but spectral properties of
light are not colors. Just like colors, the mind, free will, are real,
but not in the way Mr. Brooks apparently thinks: they're not magic.
Neural activity makes our minds just as real as colors, but neither are
magic nor do they exist outside of our heads. The fact that we don't
understand, yet, how the brain does that, is not a valid reason to
explain our ignorance away with magic, but a boon to neuroscientists (or
we'd be unemployed). The correct answer to the question: "what is the
mind?" is not "magic", but "we don't know how, but all the evidence says
it's our brain that somehow creates it".

This very fundamental insight of the last 40 years or so of
neuroscience, obviously entails that with every discovery we will be
better able to predict future actions. If that seems disappointing,
tough luck, live with it. Today, we clearly cannot "take pretty
brain-scan images and \[...\] use them to predict what product somebody
will buy", this is pop-neuroscience. However, much like we got better at
predicting the weather by studying it, we will get better at predicting
future actions by studying the brain -- as we have already become much
better over the last decades. Importantly, and I cannot stress this
enough, we don't need magic to understand that we will nevertheless, not
even with unlimited time and resources, *never* be able to fully predict
human behavior. Just like no neuroscientist postulates magic in our
heads, no meteorologist would postulate that it's magic that prevents us
from making accurate weather forecasts and no astrophysicist would claim
that magic messes with Pluto's unpredictable orbit. Apparently, it will
take a few more decades until it sinks in that the brain is a little
more complex than the weather or our solar system. Anybody who thinks
that the brain needs magic to bring about the mind with free will
thoroughly underestimates it. Everybody and their grandma today has
already realized that complex nonlinear dynamics ("butterfly effect",
"chaos" -- coincidentally coined in the same decade that dualism
essentially died) prevent accurate weather forecasts on a principle
basis, not out of technical problems. These effects even make the orbit
of Pluto unpredictable! The data from brain recordings and behavioral
studies show mathematically analogous nonlinearities, which lead to the
predictability of behavior to decay exponentially with the forecasting
period [even in
flies](http://brembs.net/spontaneous/mayeetal_2007.html). Clearly, one
can assume that humans are less nonlinear and more predictable than
flies as apparently [Joshua Greene at Harvard seems to
postulate](https://www.wjh.harvard.edu/~jgreene/GreeneWJH/GreeneCohenPhilTrans-04.pdf),
but even as a fly researcher, I find that somewhat hard to accept. But
hey, what does a fly guy know? Be that as it may, as long as humans are
equally or less predictable than fruit flies, the data from our own
little lab alone already alleviate Mr. Brooks' fears: brains will not
become fully predictable with more neuroscience, only gradually more so.

It seems there is a deep-seated frustration that science explains away
magic, even in otherwise science-o-phile individuals. More and more
research ([some of it reviewed
here](https://bjoern.brembs.net/?wpdmact=process&did=MTQuaG90bGluaw==))
is accumulating that demonstrates that not only our flies, but many,
perhaps all animals have the capacity, given the right circumstances, to
make different decisions under identical circumstances. In fact, as has
[often](https://else.econ.ucl.ac.uk/papers/prote.pdf‎)
[been](https://beheco.oxfordjournals.org/content/22/4/831.full)
[argued](https://link.springer.com/article/10.1007/BF00815496#page-1)
([review here](http://blogarchive.brembs.net/content39.html)) before,
such protean behavior is a prerequisite and an inevitable outcome of
[evolution](http://blogarchive.brembs.net/comment-n616.html){target="_blank"}.
Why should animal brains possess this capacity and human brains not? If
this kind of free will disappoints you, tough luck, live with it. Free
will is the capacity of the brain to make decisions that are
*influenced* by all the events leading up to the decision, but not
*determined* by them. Free will is a brain capacity that is of course
determined by neural activity, but the neural activity is no more
[deterministic](http://blogarchive.brembs.net/comment-n807.html) than
the weather is. In fact, I would postulate that our brains are even less
deterministic than the weather. Call it wiggle-room, or [elbow
room](https://www.amazon.com/Elbow-Room-Varieties-Worth-Wanting/dp/0262540428),
the nonlinearity of decision-making relegates the question of just how
deterministic the brain really is to a (highly interesting!) academic
debate: in practice, brains will always be less predictable than the
weather, [irrespective of any quantum effects playing a role or
not](https://www.scientificamerican.com/article.cfm?id=finding-free-will){target="_blank"}.
This modern, scientific concept of free will emphasizes that our freedom
can of course not be absolute. Freedom is always a matter of degree, of
shades of gray between the blacks and whites of determinism and
stochasticity. In fact, this is precisely how such nonlinearities
operate, by implementing deterministic and stochastic components to
create phenomena that are neither fully deterministic nor completely
stochastic. As we understand the deterministic components better, we get
better at predicting nonlinear behavior, but the very nature of all of
these systems fundamentally prevents fully accurate forecasts. In
reality, we create [robots with free
will](http://blogarchive.brembs.net/comment-n778.html), we even start to
understand the neurophysiological mechanisms by which neural processes
become unpredictable, but Mr. Brooks writes in the NYT that because he
doesn't understand how the neurons are doing it, it must be magic.

For the life of me, I have no idea what is getting into people like Mr.
Brooks who at least give off the very succinct impression that they fear
that the human brain needs magic, or else we might one day understand it
too well for our own good. Have they no respect for the lump of tissue
between their ears? At least he gets a thorough bashing in the many of
the comments and of course by the inimitable
[Neurocritic](https://neurocritic.blogspot.de/2013/06/a-conversation-on-mindless-neuroscience.html).

One of our graduate students might have just discovered the neural
circuit that allows fly brains to decide which way to turn, even in a
virtual environment without any cues. Now please excuse me while I go
back to explaining away some magic by studying fly neurons.


To my knowledge, no neuroscientist hypothesizes that there is magic in our heads. However, it appears this is a hypothesis that flies by the editors at the New York Times.

Messages de Rogue Scholar

Chance in animate nature, day 3

Free will: it’s not what you think it is