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Nature 461, 50-51 (3 September 2009) | doi:10.1038/461050a; Published online 2 September 2009

Neuroscience: Persistent feedback

Hyojung Seo¹ & Daeyeol Lee¹

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Abstract

How does the brain remember the consequences of our actions? Persistent activity in the prefrontal cortex and basal ganglia may be crucial for learning correct actions through experience.

Do you jump out of bed when you hear the alarm clock ring in the morning? Or do you push the snoozer? Your choice will depend on the consequences of similar actions in the past. Typically, if an action triggered by a stimulus leads to a pleasant outcome, such as food or safety, we are more likely to perform the same action on re-encountering the same stimulus¹. Therefore, a fundamental building block in shaping behaviour is the relationship between a sensory event, a chosen action and its consequences, but how the brain stores this information is still a matter of speculation. A recent paper in Neuron by Histed et al.² sheds some light on these mechanisms by showing that neurons in the primate prefrontal cortex and basal ganglia display persistent activity that is related to the outcomes of previous actions.

A repost...

Not next year, when it will be either Anand or Topalov! But how far later?

In one of the 4 myths (depending on what you believe) on the game of chess, I held the view that we have not yet reached the stage where we expect a machine (read computer) to become World Chess Champion, notwithstanding that one win of DeepBlue against Garry Kasparov in 1997. But I left a question mark against that conclusion as I was not sure how long this state of affairs would hold, seeing the speed of progress in computer technology. More powerful processors, larger memory chips, and sophisticated software to utilize the hardware advances are hitting the road every year.

• Book information
• Total Recall: How the e-memory revolution will change everything by Gordon Bell and Jim Gemmell
• Published by: Dutton
• Price: $26.95

• Book information
• Delete: The virtue of forgetting in the digital age by Viktor Mayer-Schönberger
• Published by: Princeton University Press
• Price: $24.95/£16.95

Dec 2007.
Helen Mayberg, Eric Kandel, Catherine Lord, Paul Nurse and Donald Price

I love hearing Kandel.  How exquisite and elegant is his comprehensive way of explaining matters of mind! It is music to my ears. I guess thats my excuse for this post:) 

Roger Penrose could easily be excused for having a big ego. A theorist whose name will be forever linked with such giants as Hawking and Einstein, Penrose has made fundamental contributions to physics, mathematics, and geometry. He reinterpreted general relativity to prove that black holes can form from dying stars. He invented twistor theory—a novel way to look at the structure of space-time—and so led us to a deeper understanding of the nature of gravity. He discovered a remarkable family of geometric forms that came to be known as Penrose tiles. He even moonlighted as a brain researcher, coming up with a provocative theory that consciousness arises from quantum-mechanical processes. And he wrote a series of incredibly readable, best-selling science books to boot.

And yet the 78-year-old Penrose—now an emeritus professor at the Mathematical Institute, University of Oxford—seems to live the humble life of a researcher just getting started in his career. His small office is cramped with the belongings of the six other professors with whom he shares it, and at the end of the day you might find him rushing off to pick up his 9-year-old son from school. With the curiosity of a man still trying to make a name for himself, he cranks away on fundamental, wide-ranging questions: How did the universe begin? Are there higher dimensions of space and time? Does the current front-running theory in theoretical physics, string theory, actually make sense?

Because he has lived a lifetime of complicated calculations, though, Penrose has quite a bit more perspective than the average starting scientist. To get to the bottom of it all, he insists, physicists must force themselves to grapple with the greatest riddle of them all: the relationship between the rules that govern fundamental particles and the rules that govern the big things—like us—that those particles make up. In his powwow with DISCOVER contributing editor Susan Kruglinksi, Penrose did not flinch from questioning the central tenets of modern physics, including string theory and quantum mechanics. Physicists will never come to grips with the grand theories of the universe, Penrose holds, until they see past the blinding distractions of today’s half-baked theories to the deepest layer of the reality in which we live.

 

By Jonah Lehrer, Nature, 14 Oct '09.