Wednesday, May 16, 2007

Free Will or "free will"?

"Fruit flies demonstrate free will" - such is the reaction to a paper by Maye et al. It's co-author Brembs who's making the most impact in the blogosphere.

The press release on Brembs' own site has a writeup of the research. He states that the work has distinguished between two alternative models of behaviour (the first figure in Brembs' writeup online - also available here). The chaotic behaviour observed requires some sort of internal "initiator" within the fly's mind because:

[L]acking any input, if the flies were input-output devices, their behavior should resemble random noise, similar to a radio tuned between stations.

Is this really true?

  • Are the flies lacking any visual input, or do their visual systems create illusory input? (David - I need you to explain Ganzfeld again...)
  • What other inputs might there be from the fly's internal and external environment (muscle fatigue, air currents created by the fly's own movement...) that might have been creating input?
  • If we accept that they were receiving "no input" whatsoever, is it still true that this would necessarily result in random (rather than stochastic) behaviour?

These are genuine questions - I really don't know and I'm curious to find out. The paper's in PLOSOne - so I suppose the reviewers must have received good answers to these sorts of questions.

But now for the more grandiloquent claim - that the presence of this initiator is evidence of free will. The New Scientist review seems to suggest that the appearance of chaotic patterns in the fly's movement suggest free will.

If this initiator is initiating chaotic behaviour, how is it doing it? Does there have to be an element of "will" about it at all? After all, climate systems exhibit wonderfully complex stochastic behavior and no one (the romantic poets aside) has ever accused the weather of exercising choice.

Brembs quotes himself as saying:
"Our subjective notion of 'Free Will' is essentially an oxymoron: we would not consider it 'will' if it were completely random and we would not consider it 'free' if it were entirely determined."

So far, so soundbite. But the release goes on, at the end of the penultimate paragraph, to say:

Humans may not have free will in the philosophical sense, but even flies have a number of behavioral options they need to decide between. Humans are less determined than flies and possess even more options. With this small reformulation, the topic of free will becomes the new biological research area of studying spontaneous behavior and can thus be discerned from the philosophical question.

Aha! So it's not so much a question of whether or not flies have free will, as whether or not flies have "free will". This seems like a nice bit of semantic footwork. In the cog sci, neurophysiology and psychology fields, "free will" might be shorthand for "apparent free will". But to the rest of us free will means Free Will, in that pesky philosophical sense. In Nature Neuroscience, free will might mean "free will", but in the New Scientist, free will means Free Will.

See, this is why I dislike to science by press release. Without knowledge of the specific meaning of the terminology used in the researcher's community of practice (free will = apparent free will), the reader is left to interpret the news story in a commonsense manner (free will = Free Will). And so, in your newspaper today, expect flies to go from having "free will" to having Free Will. It's a big difference.


Bjoern Brembs said...

You're so dead on with your assessment, brilliant! It almost brings tears to my eyes (ok, maybe not quite, lol) how many intelligent and well-read people actually read the stuff we write and can see the work and thought that's been going into it!
Thank you, very astute!
I'm impressed!

Auntie Em said...

Really, honestly, Bjoern Brembs? If so well, crikey and welcome, have a cookie! You must be quite busy today I would have thought? Thanks for dropping by and raising the tone.

Will read with interest how the discussion develops on your blog (thanks for the blogroll!) and properly absorb the paper via PLOS One.

DavidC said...

Interesting work! I've skimmed through the PLoSOne paper, and couldn't see anything specifically on "free will" or Free Will. It seems to be only in the "mass media" that any reference is made. My hunch is that cutting off the input and the output is not enough: you'd also have to cut off all the previous input, i.e. the fly's previous life experiences, and even any genetic "experiences" that are encoded. I don't accept their premise that removing the "temporally local" inputs (i.e. their sensors - eyes, feelers whatever) and getting non-random behaviour in any way indicates free will. They could still be behaving in a way consistent with their "global" inputs, by which I mean their sensors and their sensory history. As you say, it's a danger of science by press release. A story of non-random flies would fly. A story of flies with free will flies like fruit. Or something.

Auntie Em said...

Thanks for that, Groucho

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