Proprioception

    Oh no you might say, here he goes trying to impress us with another new vocabulary word since listening to those lectures.  But no, propriception is more commonly termed our sixth sense as in that of an awareness of our body's location (upright, moving, active, etc.), basically the position and movement of our body.  And no this is not related to the movie of the same name although who's to say? -- we all have that feeling now and then when someone is peering over our shoulder or when your gut feeling tells you to avoid taking that path or turning down that alley.  But to date, the recognized six senses are smell, touch, taste, sight, hearing and yes, proprioception.  But new on the scene, and the lead article in a recent issue of Scientific American, is the likely discovery of a seventh sense, and it's coming from a place we rarely considered...inside us.  The editor's page introduces the piece this way: In our cover story, “The Seventh Sense,” neuroscientist Jonathan Kipnis describes the relationship between the nervous and immune systems.  “Mounting evidence indicates that the brain and the immune system interact routinely, both in sickness and in health,” he writes.  The immune system may “qualify as a kind of surveillance organ that detects microorganisms in...the body and informs the brain about them, much as our eyes relay visual information and our ears transmit auditory signals.”   

    Boring, or scientific gobbledygook; but have you ever thought of how the body gets rid of the junk that enters it, you know, the gunk in the air and our water and those dang pesticides and nano-pieces of plastic?  How does the brain avoid all that daily (hourly?) contamination?  Said the author: The tissues in the body contain two types of vessels.  Just as a house has two types of pipes that serve it, one for water and the other for sewage, our tissues have the blood vessels that carry oxygen and nutrients to them and the lymphatic vessels that remove toxins and other waste materials that the tissues produce.  The lymphatic vessels also ferry antigens—substances capable of inducing an immune response—from the tissues into tissue-draining lymph nodes, where they are presented to immune cells to be inspected for information on the draining tissue.  On detecting a problem, such as injury or infection in the tissue, the immune cells activate and migrate to the affected tissue to try to resolve the problem...The presence of both lymph vessels and immune cells in the meninges means researchers need to rethink the exact function of these membranes.  The traditional explanation holds that they simply carry the cerebrospinal fluid, which buoys the brain.  But considering how densely packed the brain’s constituent cells are and how sensitive its neurons are when they fire their electrical signals, perhaps moving all of the brain’s immune activity to its meningeal borders was evolution’s solution to the problem of allowing the immune system to serve the entire CNS (central nervous system) without interfering with neuron function.  Basically, it boils down to discovering that the immune system basically patrols the brain but otherwise doesn't hang out there and thus doesn't interfere with it, a position scientists dismissed for over 200 years (this all had to do with te blood-brain barrier thing which is, well, too much to get into).  And the immune system itself is growing more complicated, already being divided into innate (which reacts to known invaders automatically) and adaptive (which, well, adapts and adjusts to not only pathogens but apparently also to tissue which might be in the process of being damaged as well).

Rohingya refugee camp.  Photo: Ismail Ferdous for National Geographic

    Still gobbledygook?  Agreed, but it displays the complexity of our bodies and how so much of what we know only seems to reveal how much more we have yet to discover.  So let's jump over the another of our senses, that of our eyes.  There's something going on there that scientists are worried about and that's our shortsightedness.  It's now become a global epidemic and primarily among the young.  Said a piece in The Guardian: For several thousand years, human beings have lived in more or less advanced societies, reading, writing and doing business with one another, mostly without the aid of glasses.  But that is coming to an end.  No one is exactly sure what it is about early 21st-century urban living --the time we spend indoors, the screens, the colour spectrum in LED lighting, or the needs of ageing populations-- but the net result is that across the world, we are becoming a species wearing lenses.  The need varies depending where you go, because different populations have different genetic predispositions to poor eyesight, but it is there, and growing, and probably greater than you think.  In Nigeria, around 90 million people, or half the population, are now thought to need corrective eyewear...There are actually two things going on.  The first is a largely unreported global epidemic of myopia, or shortsightedness, which has doubled among young people within a single generation.  For a long time, scientists thought myopia was primarily determined by our genes.  But about 10 years ago, it became clear that the way children were growing up was harming their eyesight, too.  The effect is starkest in east Asia, where myopia has always been more common, but the rate of increase has been uniform, more or less, across the world.  In the 1950s, between 10% and 20% of Chinese people were shortsighted.  Now, among teenagers and young adults, the proportion is more like 90%.  In Seoul, 95% of 19-year-old men are myopic, many of them severely, and at risk of blindness later in life. But just seeing near or far doesn't take into account another sense, that of actually "seeing" what is going on.  The photo above comes from a fascinating story in National Geographic of how just a single refugee camp has grown so large that it is now threatening the migration routes of elephants.  But look at the photo itself...is this how you pictured the refugee and immigrant situation?  For many, this outreach camp and "temporary" housing will become their home for an average of 17 years.

   From TIME came the story of another flood of people...tourists.  55,000 per day arrive in Venice.  It's much the same in Barcelona where nearly 5 mega-cruise ships arrive daily.  They all eat, they all poop, and they all toss away trash...worldwide, a "garbage truck's worth of plastic enters the world's oceans every minute," said The Week: A lot of it winds up in five huge masses of plastic debris, called gyres, created by currents in the world's oceans.  The largest of these swirling plastic stews is the Great Pacific Garbage Patch, formed by winds and currents between California and Hawaii.  It's twice the size of Texas and "increasing exponentially," according to a study published earlier this year.  A plastic patch along the North Atlantic between Virginia and Cuba is nearly as large.  These five gyres cover as much as 40 percent of the planet's ocean surface.  To clean up all five would take 1,000 boats filtering the water 24 hours a day for 79 years...The polymers in plastics are chemically inert, but some common additives in plastic behave similarly to human hormones, and might do damage in high concentrations.  And it's becoming increasingly difficult not to ingest plastics.  A study last year found 83 percent of the world's drinking water is contaminated, while this year, researchers found 93 percent of bottled water contains some plastic, often double the amount found in tap water.

    The average 18 month old baby now has about 7 DVDs, along with all sorts of other gadgets causing scientists to question if such stimulus is perhaps harmful.  Said Scientific American: By looking at how parts of the brain used glutamate, a basic neurotransmitter involved in learning and memory, he ( Dimitri Christakis, a child psychologist at the University of Washington) has found connections to cocaine addiction in his attention-challenged mice.  Overstimulation led to more enjoyment of cocaine, less sensitization to it and ever more hyperactivity.  This is not to say that the same is true in humans or that overstimulated kids will turn to drugs, but addiction relies on reward networks in the brain and habit formation.  To better understand these ideas, Christakis  is now studying screen addiction in children as young as two years old.  That would have been unheard of a decade ago, and he says he has found it in almost 10 percent of his subjects.  Screen time harming babies?  A soaring rate of eye problems happening to teens?  Is there a connection?  And in a somewhat related piece, a study on flatulence (yes, farts) it was found that herring gulp air and expel it in short bursts, "fast, repetitive ticks -- fart dots and dashes" which is now thought to be a form of fish communication (whaaat?).

   Phew, what a total factotum of gobbledygook, eh?  So one final thought: in a series of talks titled How Colors Affect You: What Science Reveals, its been discovered that our world basically begins in black and white and that color is something which we appear to add to our brains later.  In a study with children deeply affected by trauma, their drawings had no color, only black on white paper; when the white paper was removed and replaced with colored paper the children simply stopped drawing altogether.  And here's another tidbit, throughout 99% of the world, colors are ranked in the same order...black, white, red, yellow, green and blue.  Doesn't matter the culture or the part of the world or the age, somehow we humans innately rank colors in an almost pre-patterned order.

   So there is much to learn, not only externally but internally as well, and it appears that we are learning about ourselves all the time.  Our body awareness, our proprioception, our perception and reception...our seventh sense.  But perhaps there are even more senses?  Think of your well being and yes, how sens(e)itive you are.  Wonders still await us, even as we and the world around us continues to change.  Sometimes all that we have to do is to look in a different direction...