I have joined with gusto the world of zombie enthusiasts.  I have a written a zombie novel detailing a semi-plausible medical approach to the development of a zombie apocalyptic plague. I am a proud member of the Zombie Research Society.   Indeed, I have had the pleasure of delivering presentations and lectures detailing the putative neuroscience of the cinematic zombie for organizations as varied as the Science and Entertainment Exchange (part of the National Academy of Sciences), medical schools across the country and at equally enjoyable horror conventions.  I even spoke at a children’s book fair in Annapolis, and I can’t wait for Comic-con.

So, what is the CDC up to here?  What would cause the most respected public service organization in the world that is entirely dedicated to the tracking and treatment of real disease to jump headlong into the zombie fray?

Well, first, and maybe even most importantly, it’s a great way to make serious stuff more fun and available  There happens to be an increasingly convincing body of educational research showing that late adolescents and adults learn better if they’re smiling and enjoying themselves. 

Imagine that!  If we educators deliver a dry and fact-laden lecture to a bunch of already coffee-needy adults, their brains shut down before they’ve taken their first set of notes.  A bad lecture has been described by some as one individual delivering content from one piece of paper directly to somebody else’s piece of paper, without allowing the content to pass through either person’s brain in the first place. 

BUT - if we make ‘em laugh, get them to chuckle, cause them to smile and take notice…well, people sit up a little straighter.  The research suggests that in these circumstances adults especially think less about their coffee and focus more on what the teacher has to say.

And, as you might expect, there’s a neurobiological explanation to all this that simply accentuates much of what we teachers have known for a while.  If you take your students by surprise, if you force their brains into an active mode, and especially if you do this by entertaining them and also making them a tiny bit anxious, then your students take in, play with, and more readily retain what you’re trying to teach. 

To understand why this approach works best with adult brains, there are key concepts that need defining.  Indeed, it is my hope that by dissecting the neurobiology of adult learning, I can both explain and endorse what I imagine was the strategy of the CDC in posting their marvelous zombie alert.

So, here’s what happens as you grow up:  your brain grows up.  Neurons march around your head, settling in at various key morphological and functional locations, and simultaneously these neurons start to talk to each other.  It’s like the population of a once sparsely populated but clearly fertile land grows. Settlements emerge.  The neurons sort of have Tupperware parties.  They share ideas, trade impulses, swap content, and add to each other’s experiences.  If you look under a microscope at a section of an infant brain and compare it to a slide of the same region from an early adolescent brain, you can literally see, much like developing suburban subdivisions, the movement and increased density of neurons as the brain grows.  In particular, neurons cluster in the frontal cortex and the prefrontal cortex.  In other words, we develop a greater density of neuronal presence in the region of the brain required to make sense of a complex world.

But then, sometime around mid to late adolescence, something funky happens.  Our brains start to “prune” those connections.  Axons that once talked without reservation with other receptive neurons start to disappear, and the once thriving tree of neuronal connections looks increasingly like a well-tended shrub in a French garden.  The tree analogy is used often in neuroscience when describing these processes.  Hence we have terms like “arborization” for the growth of the connections among neurons, and “pruning” for the whittling away of these conntections.

What’s going on?  What could be the adaptive purpose of this strange pruning just as the brain is making sense of the world?  From an evolutionary perspective, scientists have postulated that after adolescence is over or nearly over, we need to have pretty much learned what we need to know in order to go forth and prosper.  Connections that matter – where to meet your mate, for example, or how to work your i-phone – are preserved, but some of the other stuff is weeded out and left to die.  If you’re a sports fan, you’ll see this when you try to match wits with a young version of yourself while reciting important statistics about players for your favorite team.  The kid’ll know more and be able to access that information with greater ease and facility.

This is the neurobiological basis for “confirmation bias,” the cognitive error of selectively listening for data that supports what you think you already know.  Adults are literally wired to be sure that they know what they need to know, and they rely on “pattern recognition” to confirm their preconceived notions.