When
I was in third grade, Miss Small, a stout, grey-haired, no-nonsense Sunday School teacher who
showed up every week in the same charcoal suit and white silk blouse, stunned our
entire class by cracking a raw egg into a glass of beer, soberly warning us
that the egg represented our brains. The
lesson itself, if there was one to be had, was lost on us as we squirmed and
snickered in awkward awe at that can of Pabst Blue Ribbon sitting there on a Sunday morning in our Southern Baptist church. Truth be told, there wasn't an eight year old
among us who had ever been in close proximity to a can of beer, much less breathed
in its yeasty aroma as it bubbled and frothed its way to the top of the
glass.
Turns
out, Alice Small may have been ahead of her time, at least in likening a brain
to an egg. In the mid-1980s the Partnership for a Drug-Free America
launched a campaign with an ad which showed a close-up of an egg dropping into
a frying pan, while a voice in the background uttered the now ubiquitous phrase:
“This is your brain on drugs. Any questions?”
Aside
from the fact that the texture of a brain is more like a bowl of Jell-O than an
egg yolk, these metaphors allude to a revolutionary reality that the exploding study of the
human brain called neuroscience has uncovered. Simply put, our brains are malleable, subject
to change, and not hard-wired in the womb in some unalterable fashion as was
once assumed. This means that not only
what we do and how we do it, or what we know and how we learn it, but every
single life experience has the potential to alter the very structure of that
three-pound organ that sits atop our neck, persistently utilizing 20 percent of
our body’s energy, even when we are asleep.
There
is both good news and bad news in this, and in the coming weeks I will be
exploring why it matters, particularly to those of us who seek to follow
Christ. Eventually I hope these
meanderings make their way into my next book, so I hope you’ll come along on
this journey, sharing your thoughts and questions as we go.
Over
the past several days I have immersed myself in material on the brain, trying
to get a layperson’s grasp of the current knowledge. The more I have read, the more profoundly I
have felt my finiteness. It’s as if I’m
trying to navigate some vast foreign country without a compass, plundering across an
exotic terrain that holds mystery and intrigue, symmetry and precision, while
the best mapmakers in the country lament the immense swaths of yet uncharted
territory.
Although scanning limitations have relegated neuroscientists to observing a piece of the brain so miniscule that it could fit on the end of a straight pin, that small fragment has revealed a world of activity a bit like New York City in the height of rush hour. Here’s just a smattering of what they've discovered:
- Your brain hosts 100 billion neurons (nerve cells) roughly the same as the number of stars in the Milky Way, each one unique, resembling a branch of a tree and exquisite in its complexity.
- These billions of branch-like neurons communicate endlessly and intricately with each other, like friends talking on the telephone.
- The synapses that connect these neurons throughout our brain measure upwards of 100,000 miles.
- It appears that our thoughts, perceptions and memories shuttle along these synapses like racecars at speeds of up to 250 miles per hour, escorted by neurotransmitters such as endorphins to reduce pain and increase pleasure, adrenaline to keep us alert and balance our blood pressure, or serotonin to regulate our appetite and mood (to name a few).
- When we go to sleep at night, this activity continues as our brain sets about the task of pruning. Neurons grow new branches and lose old ones, while synapses may be strengthened, shrunk, created or destroyed. This is the changing nature of our brains.
If
this seems slightly overwhelming to you as it did me, then you are in good company. Dr. Sebastian Seung, professor of
computational neuroscience at MIT, shared his own emotional response to this
study to which he has devoted his life:
As a scientist, I am not supposed to talk about my feelings. “Too much information, professor.” But may I? I feel curiosity and I feel wonder, but at times I have also felt despair. Why did I choose to study this organ that is so awesome in its complexity that it might well be infinite? It’s absurd. How could we even dare to think that we might ever understand this? [italics mine]
For me, this gives new meaning
to the reality that we humans are created in the image of God. I can only conclude, as did the Apostle Paul:
Oh the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways! For who has known the mind of the Lord, or who has been his counselor?...For from him and through him and to him are all things. To him be the glory forever. Amen (Romans 11:34-36)
Next week: Why your brain’s malleability is good news for the soul.
Resources:
The Astronomist: A Cubic Millimeter of Your Brain. (2011, July 27). Retrieved from http://theastronomist.fieldofscience.com/2011/07/cubic-millimeter-of-your-brain.html
Greenfield, S. (2000). The private life of the brain: Emotions, consciousness, and the secret of the self. New York: John Wiley & Sons.
Horstman, J., (2009). The Scientific American day in the life of your brain. San Francisco: Jossey-Bass.
Seung, S. (2013). Sebastian Seung: I am my connectome TEDTalk - YouTube. Retrieved from https://www.youtube.com/watch?v=Dl850CUX4Rw&noredirect=1
Zimmer, C. (2014, February). Secrets of the Brain [e-magazine]. Retrieved September 9, 2014, from http://ngm.nationalgeographic.com/2014/02/brain/zimmer-text
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