25 June, 2009

Uncertainty About Free Will

Martin Heisenberg, son of the famous Werner, wrote a piece concerning the uncertainty of the existence of free will in Nature last month.

Our influence on the future is something we take for granted as much as breathing. We accept that what will be is not yet determined, and that we can steer the course of events in one direction or another. This idea of freedom, and the sense of responsibility it bestows, seems essential to day-to-day existence.

Yet it is under attack as never before. Some scientists and philosophers argue that recent findings in neuroscience — such as data published last year suggesting that our brain makes decisions up to seven seconds before we become aware of them — along with the philosophical principle that any action must be dependent on preceding causes, imply that our behaviour is never self-generated and that freedom is an illusion

Heisenberg is a neurobiologist at the University of Würzburg, where he studies brain function in Drosophila. He argues that in order to gain insight into free will, it is advantageous to study animal behaviour, such as the motor behaviour of E. coli.


As with a bacterium's locomotion, the activation of behavioural modules is based on the interplay between chance and lawfulness in the brain. Insufficiently equipped, insufficiently informed and short of time, animals have to find a module that is adaptive. Their brains, in a kind of random walk, continuously pre-activate, discard and reconfigure their options, and evaluate their possible short-term and long-term consequences.

So this suggests that decisions are not simply responses to external stimuli but they can be made internally, not only by humans but by all life, albeit randomly in many cases. The fact that a bacterium changes direction at all in the absence of external stimuli supports this view. Heisenberg argues that this is a rudimentary form of free will even if the bacterium is not conscious of itself and is not conscious of its random 'decision' to change direction.

Some define freedom as the ability to consciously decide how to act. I maintain that we need not be conscious of our decision-making to be free. What matters is that our actions are self-generated. Conscious awareness may help improve our behaviour, but it does not necessarily do so and is not essential. Why should an action become free from one moment to the next simply because we reflect upon it?

I like this idea.

To extrapolate, neurons in the brain must be firing randomly almost constantly in tandem with what you might call unrandom or controlled firing (just a hunch, I have no data to back that up). It seems possible that random firing of neurons in our brains might be the actual source of consciousness and free will. Throughout evolution, as brain size increased, more complex animals may have evolved consciousness, which allowed them to control and use these random firings to their advantage, e.g. the ability to make a decision which seems wrong in the short term but is actually beneficial in the long term. This decision making process, which goes against the immediate external stimuli, is what I would call free will. A decision based solely on external stimuli is simply what we call instinct. So free will is random in less complex organisms but is actually somewhat self-controlled in humans and some other species.

Robert Doyle has responded to Heisenberg in the latest edition of Nature and seems to agree.

The philosophers' standard argument against free will is simple and logical. If our actions are determined, we are not free. If nature is not determined, then indeterminism is true. Indeterminism implies that our actions are random. If our actions are random, we did not will them.

Heisenberg's proposal makes freedom a normal biological property of most living things, and not a metaphysical mystery or a gift from God to humanity. The genius of this proposal is that it combines randomness with an adequate macroscopic determinism consistent with microscopic quantum mechanics.

Interesting stuff.

Now, it's nice and sunny in Dublin and I think I'm in the mood for some ice-cream.

Or am I?

6 comments:

Anna Sethe said...

I know Martin Heisenberg :D

I got my degree in neurobiology at the University of Würzburg.

He's absolutely fascinating (people tend to either love or hate him, I'm definitely one of the former).

And while I was there he had a tiny little VW. I really like it when the big guys look like normal people ;)

rhiggs said...

No way!

That's so cool...!

I know nothing about him other than what I read to write this article. His work sounds very interesting. Are you involved in anything similar?

Why does he divide opinion so much? Is he living in the shadow of his father?

Anna Sethe said...


I know nothing about him other than what I read to write this article. His work sounds very interesting. Are you involved in anything similar
?

I work with bee brains at the moment. Heisenberg and my boss are quite good friends, we collaborate a lot.

Why does he divide opinion so much? Is he living in the shadow of his father?

I've never seen the shadow of his father at the university ;)
Truth is, many biologists know so little about physics that Werner Heisenberg is just a famous name. And actually his son deserves a Noble prize of his own, but insects are a little underrepresented among the Noble prize laureates...

I think he devides opinions so much because he's opinionated and sometimes a little bit too smart for his own good. He sees the big picture. And some people seem to think you shouldn't do that too much when you only work with fruit flies.

I don't really understand it but I once almost started a fist fight when I mentioned his name in a group of university professors.

Jealosy?

rhiggs said...

Cool. I'm quite interested in Drosophila because of their Toll receptors. They are involved in development in fruit flies (maybe bees too?) but their vertebrate homologs, the Toll-like receptors, are essential in pathogen recognition and innate immunity. I've been working on the TLRs for the past 5-6 years now...

And yes it's probably jealousy. The more senior some people get, the more childish they become...

capdancer said...

Nice review of the article. Raised a question in my mind (probably not freely): if the random noise of the brain is the source of 'free will', then why not the soul, too, and a means to prove the existence of God...or at least justify belief in the same. I'm not inclined to believe in free will; this seems like an attempt to define 'freedom' as mere randomness - stochastic behaviour. What it comes down to for me is the 'how', which is ultimately as series of spatio-temporally connected 'whats': if the random firings of neurons in the brain *are* responsible for free will, what is the mechanism connecting the two? An incidentally observed phenomenon may be sufficient basis for a scientific theory, but does not justify its acceptance. Also, I question whether 'free will' is, by that definition, of any value; character is determined by experience + genetics, and has a major role in determination of behaviour...which is the subject about which we are concerned, is it not?

It is good to know that scientific mavericks are still at large, though, from the other comments - I have a theory, that collaborate & publish or die may be true, but only because the people at the top don't want to lose their jobs, so they have re-defined successful scientists as being like them - highly collaborative and published - while the reason for their success (longevity) might be more about their early seminal contributions, that made them desirable as collaborators or highly cited. More on that anon...

rhiggs said...

Hi Capdancer,

Welcome and thanks for the comment.

You said: "if the random noise of the brain is the source of 'free will', then why not the soul, too, and a means to prove the existence of God...or at least justify belief in the same."

For me, it depends how you define the 'soul'.

If you mean it to be some sort of state of consciousness and self-awarness that humans have, then I would think it's plausible that both free will and the soul are somewhat connected and may have originally evolved from random noise in the brain. Note that I am not saying they are completely contolled by random noise, but this may have been their origin.

However, if you define the 'soul' as being some sort of transcendant entity within each of us that will live forever, and I suspect you do given your comment about God, then I will have to disagree. I just don't believe in transcendant entities like souls or Gods. Also, even if reasonable evidence of a soul ever emerged, it wouldn't prove the existence of God, just the existence of souls (although I agree it would lend some credence to belief in God).


"I'm not inclined to believe in free will; this seems like an attempt to define 'freedom' as mere randomness - stochastic behaviour."

Do you not believe in the randomness theory of free will being proposed here, or do you just not believe in free will at all? I mean, did you decide to repsond to this article or was it pre-determined?


"What it comes down to for me is the 'how', which is ultimately as series of spatio-temporally connected 'whats': if the random firings of neurons in the brain *are* responsible for free will, what is the mechanism connecting the two?"

Good question. I have no idea but I don't think it's too big a leap to think of random firing of neurons causing bigger whole body effects. It's easier to think of it in terms of a bacterium though. According to the article, if a bacterium is in a stimulus-free environment it will still move around. If it acts purely on 'instinct', i.e. response to stimulus, then it shouldn't move at all. But it does! So there must be some other mechanism at work, either intelligence or randomness. I think we can rule out intelligence, so randomness must somehow control movement in this scenario. (Please note I do not claim to be an expert so this is complete speculation - I will happily be corrected)


"An incidentally observed phenomenon may be sufficient basis for a scientific theory, but does not justify its acceptance."

Agreed


"Also, I question whether 'free will' is, by that definition, of any value; character is determined by experience + genetics, and has a major role in determination of behaviour...which is the subject about which we are concerned, is it not?"

Interesting point. I would tentatively agree that the term 'free will' may be redundant. My own non-expert opinion is that perhaps free will may have originated from randomness, but in humans free will is somewhat under control and is a trade off between intelligence and instinct.


Very interesting topic all the same. Thanks for your input!