“Every man takes the limits of his own field of vision for the limits of the world.”
—Arthur Schopenhauer, Studies in Pessimism

Riding in a Manhattan subway car the other morning, I read that quote by 19th-century German philosopher Arthur Schopenhauer on one of the transit authority’s “Train of Thought” posters. It amused me that I had actually gone underground to see the light. That is, Schopenhauer’s words captured clearly what I had been only vaguely mulling about some of this issue’s major features and what they represent: the utility of looking at an area of science anew by coming at it from a different perspective. In this, I realize, I am hardly the first person to notice that when attempting to solve a problem, changing your physical vantage point or mental framework can loft you past perceived limits. In some cases, it can be difficult to recognize evidence that may be right before your eyes because you fail to appreciate it for what it is.

And so it was with the subject of this month’s cover story. What scientists once thought was unremarkable cellular “noise” in neuron signaling has come to be viewed as important to overall system-wide functioning in the brain. It’s common, and completely understandable, for researchers to strip noise from any signals they are trying to measure. But neuroscientist Marcus E. Raichle, author of “The Brain’s Dark Energy,” was one of the first to wonder whether the noise itself had meaning. As he later said at a conference on brain network dynamics, “It turns out that this is yet one more signal in the biological world whose ‘noise’ is highly important and is very information rich.”

Raichle, a pioneer in the use of brain imaging, and his colleagues have observed that in brains at “rest”—when you are not thinking of anything in particular or even when you are asleep—dispersed areas are still buzzing with communication. This intrinsic activity he calls the brain’s default mode. Determining the exact role of this previously unappreciated “dark energy” is an ongoing area of study, but it appears to be involved in how the brain prepares for future events that involve conscious processing. Disruptions of such activity may underlie certain brain disorders as well.

In another feature article, geochemist Robert M. Hazen also proposes a new view—one applied to our understanding of how Earth’s deep geohistory shaped its mineral riches. Once there were mere dozens of minerals in the universe, but today our planet has more than 4,400 known mineral species. How did that diversification happen?

In “Evolution of Minerals,” Hazen suggests we reconsider mineralogy, which does not traditionally look beyond minerals’ timeless properties. He and his colleagues use “Earth’s history as a frame for understanding minerals and the processes that created them.” With this long-range lens, it becomes clear that the rise of life and its metabolic activities dramatically directed our planet’s uniquely diverse mineral kingdom. Up to two thirds of the mineral species co-evolved with life through a series of epochs. The “rock of ages” takes on a whole new meaning.

This article was originally published with the title Limits of Perception.

9 Comments

1. 1. wolfkiss 01:08 PM 2/17/10

   I'm pleased that Marcus E. Raichle has seen the light. But this is just another in a very, very long line of assumptions that amaze and frustrate me. Having attended numerous neuroscience and cognitive computing lectures over the years, I'm simply amazed at how quickly very intelligent people will assume that because they don't understand a phenomenon it is merely “noise”. And, once labeled noise, its meaningfulness is severely demoted.
   
   Please forgive my rant. But it never fails to amaze me how much relevant information PhDs will blithely discard if it does not fit their focused and rigid world view. Case in point: white, pink and brown noise in the brain. Just the mere fact that these different forms of noise in the brain have different power spectrums should be a massive indication that they are distinct for some evolved reason. And, on the point of evolution, it is quite clear that nature selects for efficiency. How else could the brain do what it does and use orders of magnitude less power than our digital tools, which can barely simulate a mosquito’s neural function, let alone a 3 year old human? Over billions of years of evolutionary pressure, it makes no sense that the majority of power in the brain would be expended on useless noise. And the idea that the brain turns “off”. This has been known for decades to be incorrect; e.g. REM sleep.
   
   I understand and strongly support empirical rigor and that knowledge should be vetted by verification with the physical world. And it further makes sense that poorly understood phenomena would be demoted until they can be fit into the larger model. But our reductionist brand of science needs a serious overhaul; it needs vision. Our educational institutions need to foster more critical thinkers that can knit formerly disparate threads of existing empirical knowledge into more inclusive theories. We have the facts, but we need to be more creative and logically critical in imagining how they can go together. Those schooled in such a discipline could work with the very focused PhDs to refine our understanding at much greater rates than today; rendering a lot of “noise” a lot more useful than we pre-conceived.
   
   Does anyone share this sentiment? Or, do most feel that our scientific institutions are just fine the way they are? I’m really interested in people’s thoughts on this.
   
   Cheers.
   

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2. 2. krohleder 02:38 PM 2/17/10

   "it never fails to amaze me how much relevant information PhDs will blithely discard if it does not fit their focused and rigid world view"
   
   It is not just PHD's it is everyone! Only temporary fleeting moments of creative genius escapes it; barely.

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3. 3. krohleder 02:41 PM 2/17/10

   “All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability”
   
   - David Hume

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4. 4. Intuitive 06:19 PM 2/17/10

   And Why? such credit must always be assumed and given to PHds in discovery when it has been always been there, not by evolution, because lest we forget, man is so good at destruction, but God since men have only touched the tip of the iceberg in "noise" that can be identified. Darwin only popped a theory remember, not a fact.

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5. 5. Hussain 08:04 PM 2/17/10

   i was woundering if it was possible to buy the article instead of the whole issue?
   
   
   thanks

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6. 6. TTLG 08:57 PM 2/17/10

   There is an old joke from Dilbert (and other places): If I don't understand it, it must not be important. But I agree that it is unfair to blame scientists for this, especially. If there is any group around who manage to get over their prejudices, it is them. Try to find one who still thinks that "junk" DNA really is junk. On the other hand, try to find a politician or political pundit who admits that their biases were wrong in the slightest way. Rarer than hen's teeth.
   
   Which explains why science keeps advancing while politics has not had any real improvements in hundreds of years. Lets get more science in our government.

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7. 7. SciJer 09:17 PM 2/17/10

   And let's get the politicians out of the science!!!

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8. 8. ormondotvos 10:15 PM 2/17/10

   Hens have teeth. They're in the stomach. The other teeth are the beak. QED :-)

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9. 9. Hussain 06:38 AM 2/18/10

   oh please if someone can answer my previously posted question i would appreciate it
   
   
   "i was woundering if it was possible to buy the article instead of the whole issue?"
   
   
   

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