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Archive for the ‘neuroscience’ Category

I don’t know if it was divine intervention, or the kinship of all living things, but I tell you, Jerry, at that moment…I was a marine biologist!

There’s a debate underway between two schools of marine biologists. The received wisdom is that the brains of whales and dolphins evolved to promote cognitive advantages. The challenging hypothesis is that cetacean brains evolved to prevent heat loss due to changes in water temperatures, and their size cannot be taken as evidence of complex cognition.

Here’s the paper that started the controversy:

It’s governing logic is simple. Absent evidence for complex cetacean cognition, parsimony in scientific explanation – whether you call it simplicity or Occam’s razor – demands a more minimal hypothesis.

However, this is a politically and emotionally loaded issue, so it’s only to be expected that a challenge to whales’ cognitive ability will provoke a response. That’s what happened with the publication of a recent paper in PLoS Biology, just in time for the meeting next week of the International Whaling Commission. The paper has a clear, declarative title:

Their’s is a two part argument, and it attacks the premise of Manger’s argument from parsimony: cetacean neuroanatomy is indeed complex enough to support cognition like that of terrestrial mammals, and cetaceans do indeed demonstrate complex cognitive behaviour.

Perhaps I’m missing something, because Manger’s attempt to exclude the possibility of complex cetacean cognition seems to be a red herring. We can have it both ways: complex cognition and temperature regulation do not need to be mutually exclusive evolutionary developments.

Note: I’ve tagged this with ‘neurolaw’ because this has implications for international law governing the whale hunt. It’s a good reminder that neurolaw isn’t just about humans.

(Hat tip to Science and Consciousness Review for mention of the PLoS article.)

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Quirks and Quarks is the CBC’s science show, a hackneyed beast with a tendency towards covering dinosaurs, animal sex, and the occasional environmental hot potato. It’s popular science journalism but not science news – it can take weeks before a science story appears in their line-up, although they were among the first to talk about the weirdness of ducks’ reproductive organs.

Whatever complaints I might have about their programming, they get it right when it comes to putting their shows online. Live broadcast, archived shows, podcast, it’s all there for download – in mp3 and ogg format, no less – and provides off-site links to researchers’ websites and publications.

Other shows on Canada’s public broadcaster should have open access programming like this, and not just because it lets me link to the following show, broadcast today but already archived on their website:

Neuroscience and the Law has interviews with Marc Hauser on moral decisions and Frank Tong on ‘mind reading’ applications which might detect lies and object recognition. These are bracketed by comments from law and biology professor Owen Jones and Canadian neuroscientist Lesley Fellows.

Despite the corny ‘you are the jury’ presentation, this series of interviews has an advantage over the New York Times’ article, Brain on the Stand: the researchers have more time to talk about their work and its implications. It also helps that the host, Bob McDonald, is an excellent interviewer and can walk a general audience through complicated science.

It’s worth a listen, even if you’ve never wondered about the pronunciation of ventromedial prefrontal portex, so click through to the audio archive…

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Mark Caldwell has written a special feature for Science Magazine on Neuromarketing Careers. It is worth a read if you’re interested in the future of the business.

Unfortunately, a Google search for “careers in neuroethics” returned exactly zero results.

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If we could find a necessary or sufficient condition for free will in the minds of fruit flies, would we bug out just a little? Sure we would, and then we’d blog about it.

Here’s the paper that started it all.

From the abstract:

Instead of random noise, we find a fractal order (resembling Lévy flights) in the temporal structure of spontaneous flight maneuvers in tethered Drosophila fruit flies. Lévy-like probabilistic behavior patterns are evolutionarily conserved, suggesting a general neural mechanism underlying spontaneous behavior. Drosophila can produce these patterns endogenously, without any external cues. The fly’s behavior is controlled by brain circuits which operate as a nonlinear system with unstable dynamics far from equilibrium. These findings suggest that both general models of brain function and autonomous agents ought to include biologically relevant nonlinear, endogenous behavior-initiating mechanisms if they strive to realistically simulate biological brains or out-compete other agents.

The paper involves math. If you get lost, look for good stuff in the section titled ‘Brains are simultaneously indeterministic and deterministic for a reason’. You get gems like:

Brains indeed do throw the dice–but by refuting the notion of stochasticity our results imply that they have exquisite control over when, where and how the dice are thrown.

Hat tip to LiveScience for mention of the story, clear writing without any (gasp) math, and lots of fun quotes from the researchers making it clear they are targeting this research towards development of autonomous robots.

Update: A Blog Around the Clock points to this researcher’s description of the experiment. It includes video of a tethered fruit fly.

Update: Nature columnist Philip Ball says this has nothing to do with free will, a concept that has no place in science.

Update: Philosophers at the Garden of Forking Paths – people who know free will really, really well – are wondering if the paper really tells us anything about free will. For now, the drive-by response seems to be “huh”. If the story is genuinely worthy of comment by free-will scholars, expect something of substance on that blog in the near future.

Update: In a strange turn of events, we learn free will in fruit flies is good for Intelligent Design. So says Uncommon Descent, which concludes:

Evidence for free will is evidence against Darwinism, no matter how it is spun.

Update: CBC Radio’s As It Happens interviews Bjorn Brembs. It can be found three stories and about 15 minutes into this streaming audio file.

Update: For one of the best commentaries on the research, see Good Math, Bad Math.

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In a post a few days ago, I mentioned a recent paper which dates a mutation in human evolution. That mutation expresses a neurochemical involved in earning and memory – in mice. You can find the article here:

the Women’s Bioethics Blog, now writes about this under the headline: The gene/neurochemical that may separate human/ape brains: Neuropsin II.

Be cautious about oversimplifying this, however. Their research does not identify a ‘magic gene’ which separated humans from apes. It does show a neurochemical is present in human brains and not in the brains of other primates, but the mutation may have happened sometime after humans diverged from chimpanzees 5 million years ago.

Update:  NewScientist reports this as Gene variant may be responsible for human learning.

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