This Is Your Brain on Bytes

It’s mind-boggling time.  Some recent articles have tried to quantify the information capacity of the eye, the brain, and the world.  Ready?  Think hard.

1. Eye boggle:  Your eyes contain about 120 million rods and 6 million cones each.  If each receptor represents a pixel, that is 2 x 126 million pixels, or 252 megapixels.  And remember – these are moving pictures, not stills (talk about high-def).  How can the brain transmit and process that much visual information?  The answer is, apparently, it uses compression – just like computers compress raw camera photos into more manageable JPEG images.  That’s the title of an article on Science Daily: “JPEG for the Mind: How the Brain Compresses Visual Information.”
       The article begins, “The brain does not have the transmission or memory capacity to deal with a lifetime of megapixel images.  Instead, the brain must select out only the most vital information for understanding the visual world.”  Researchers at Johns Hopkins found that certain cells in the image transmission pathway apparently focus on highly curved edges that are the most informative, dropping flat edges – resulting in an 8-fold compression ratio comparable to the JPEG algorithm.  Eyesight compression, though, is done in-line, in real time, during the image transmission process (see also the 05/22/2003 entry).  Geeks will enjoy the punch line:

   “Computers can beat us at math and chess,” said [Ed] Connor [Johns Hopkins], “but they can’t match our ability to distinguish, recognize, understand, remember, and manipulate the objects that make up our world.  “This core human ability depends in part on condensing visual information to a tractable level.  For now, at least, the .brain format seems to be the best compression algorithm around.”

2. Cerebellum boggle:  Your cerebellum (a portion of the brain near the brain stem) is important for motor functions, emotions and language.  Live Science claims that wiring in the cerebellum starts with “surprisingly bad wiring,” because axons seeking connections to granule cells of the cerebellum sometimes link up incorrectly to Purkinje cells.  But “bad wiring” may be in the eye of the beholder, because an international team found that “a substance known as bone morphogenetic protein 4, which plays a role in bone development, helped correct these errors.”
       One of the researchers publishing in PLoS Biology explained,¹ “What we demonstrate here is that you have a negative system that repels axons from an inappropriate target, thereby steering them to the right target.”  If it works, can it be called bad?  The authors said, “In summary, we show that the specificity of the synaptic connections in the ponto-cerebellar circuit emerges through extensive elimination of transient synapses.”  But that raises an interesting question: what regulates the regulators?
3. Memory boggle:  Get ready for the punch line on this one.  An article on Live Science discussed the tipping point of human information technology from analog to digital storage.  In 2000, the article said, about 75% of the world’s information was stored in analog form (e.g., paper, analog tape, analog sound recordings).  By 2007, 93% of that information was stored digitally (computer files, digital tape, digital recordings).  Digital information can be quantified in the familiar bits, bytes, megabytes, gigabytes, yotta yotta yotta….²
       Now that information can be quantified digitally, it’s possible to estimate all the human information in the world.  As of 2007, that quantity was 295 trillion megabytes (295 x 10¹⁸ bytes, or 295 exabytes), according to Martin Hilbert of USC.  Before divulging the punch line, let’s quote the article’s comparisons:

   Have a hard time imagining 295 trillion megabytes?  Hilbert suggests thinking of it this way: “If we would use a grain of sand to represent one bit each of the 295 trillion, we would require 315 times the amount of sand that is currently available on the world’s beaches.”
   For a better idea of what these numbers all mean, Hilbert and his colleague, Priscila L?pez of the Open University of Catalonia, express the information through other analogies.
   295 trillion megabytes is roughly:
   Equivalent to 61 CD-ROMs per person on Earth.  Piling up the imagined 404 billion CD-ROM would create a stack that would reach the moon and a quarter of this distance beyond.
   Enough that, if printed in newspapers that sold for $1 each, the United States’ entire global Gross Domestic Product would not be enough to buy them all.  (The cost would be 17 percent beyond the GDP.)
   Enough information to cover the entire area of the United States or China in 13 layers of books.

   Now the punch line: that incredibly huge amount of information represents “still only enough for 0.33 percent of the information that can be stored in all DNA molecules of one human adult.”  Let’s do the math: multiply all the values in the quote above by 300, and you get into the ballpark of the information storage inside your body: 94,500 times the grains of sand of all the world’s beaches; 18,300 CDs for every person on Earth, enough to reach over halfway to Mars; 350 times the GDP of the US if printed in $1 newspapers; enough to cover the US in 3,900 layers of books.  Now you know.

4. Brain boggle:  If your mind is not sufficiently boggled yet, let’s finish with a measurement posted on Wired Science.  Author John Timmer of Ars Technica expanded on the work by Hilbert and L?pez to estimate the processing power of the human brain.  After several more mind-numbing analogies of the combined processing power of all the world’s computers, storage and memory, the article ended with another surprise.  First, Hilbert and L?pez estimated the combined processing power of all the world’s computers at 6.4 x 10¹⁸ operations per second.  Then, Timmer wrote:
   

   Lest we get too enamored with our technological prowess, however, the authors make some comparisons with biology.  “To put our findings in perspective, the 6.4*10¹⁸ instructions per second that human kind can carry out on its general-purpose computers in 2007 are in the same ballpark area as the maximum number of nerve impulses executed by one human brain per second,” they write.
       Our total storage capacity is the same as an adult human’s DNA.  And there are several billion humans on the planet.

You may now put an ice pack on your head and reboot.

1.  Kalinovsky et al, “Development of Axon-Target Specificity of Ponto-Cerebellar Afferents,” Public Library of Science Biology, 9(2): e1001013. doi:10.1371/journal.pbio.1001013.
2.  A byte is 8 bits (in the ASCII encoding format).  Kilobyte=10³ bytes.  Megabyte=10⁶ bytes.  Gigabyte=10⁹ bytes.  Terabyte=10¹² bytes.  Petabyte=10¹⁵ bytes.  Exabyte=10¹⁸ bytes.  Each level represents 1000 times the prior category (10³).  Those wanting to boggle their brains further can consider zettabytes (1000 exabytes), yottabytes (1000 zettabytes), brontobytes (1000 yottabytes), geobytes (1000 brontobytes)….

While reading this article, your brain just outperformed all the computers on the planet, and your body stored genetic information that, if stored on CDs, would reach over halfway to Mars.  And who could forget the stunning analogy we published nine years ago about the information storage capacity of one cubic millimeter of DNA? (see 08/16/2002).  Facts are powerful things.  The information in this article could be taught with some clever presentation slides or posters.  Nothing is more effective than facts like these to make people reconsider assumptions about how the human body and brain came to be (see 01/19/2011 commentary).
    Evolutionists want you to believe this all happened by chance, through mistakes, without purpose or guidance.  How about asking for a time out in your local high school biology teacher’s evolution spiel to write some of these facts on the board in front of the students?  Then say (nicely), “According to your textbook, evolution teaches that your brain, but not computers, got here by mistake.”  You don’t even have to put the school at risk of a lawsuit by setting off the alarms with the emotionally-charged phrase “intelligent design.”