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The Importance of Externalizing Our Brains

By Dave Stuart Jr.

Thinking clearly is a big deal; at various times this year, it has occurred to me that it might be the biggest deal for being successful in the twenty-first century, whether you're a teacher, an administrator, a parent, or a student [1]. When a teacher learns to constantly hone her ability to think clearly, she becomes doubly effective because, first of all, she's able to reach her objectives with greater ease and, much more importantly, she's able to set those objectives much more wisely. We stop doing Pin the Tail on the Standards and start forming coherent plans for our courses, making insightful course corrections on lesson-by-lesson and unit-by-unit bases.

Clear thinking is critical to teaching and living well. It's more important than your evaluation rubric or the cool project you're working on or Insert Latest Greatest Initiative. It's more important than you reading Ms. Guru's Latest Book (although reading good books is a great way to hone one's thinking).

So what does this have to do with externalizing your brain? Maybe a lot. Let's talk about my life and index cards.

Index cards [2]

I started doing something simple in January: I kept an index card in my back pocket with the names of speaking engagement inquirers written on it. Since my brain is typically overloaded with tasks and information about teaching or writing, this inquiries area was one where I had always been quite bad. Someone would inquire, and I would respond with the requested information, and then it was really up to them to get back to me. Often, they wouldn't.

So I started writing down simple information every time I responded to an initial inquiry: their name, state, and the last date we were in touch.

Once in awhile, I'd pull this index card out of my back pocket and see that it had been a month, or even a couple of weeks, since I was last in touch with that person. I'd open up Gmail, search that person's name, and re-read our last correspondence. If the correspondence didn't give me clear indication that the delay in communication was to be expected — “I'll be in touch after our next board meeting in March,” something like that — I would just send a friendly email, something like,

Hi Susan,

I was thinking of you a few weeks ago when I found myself reading one of Mike Schmoker's books. Mr. Schmoker, as you might know, lives in sunny Tempe, AZ. I remembered that there's a chance I may one day come and work with you in the great state of AZ! I just wanted to follow up — I had forgotten until revisiting the below email string that we were discussing a potential June engagement, and June is starting to get a little trafficky for me schedule-wise.

Any updates?

I hope you're well,
Dave [3]

So I end up following through better and, most importantly, I don't end up vaguely worrying about whether or not I'm handling these inquiries well. For the first year ever, I'm booking speaking work minus the stress.

The brain

As it turns out, this index card thing is me externalizing my brain. Index cards, and the concept of externalization, came up in a book I was reading last weekend.

From Daniel Levitin's fascinating The Organized Mind: Thinking Straight in an Age of Information Overload:

When we have something on our minds that is important — especially a To Do item — we're afraid we'll forget it, so our brain rehearses it, tossing it around and around in circles in something that cognitive psychologists actually refer to as the rehearsal loop, a network of brain regions that ties together the frontal cortex just behind your eyeballs and the hippocampus in the center of your brain. The rehearsal loop evolved in a world that had no pens and paper, no smartphones or other physical extension of the human brain; it was all we had for tens of thousands of years and during that time, it became quite effective at remembering things. The problem is that it works too well, keeping items in rehearsal until we attend to them. Writing them down gives both implicit and explicit permission to the rehearsal loop to let them go, to relax its neural circuits so that we can focus on something else. … Writing things down conserves the mental energy expended in worrying that you might forget something and in trying not to forget it.

Levitin goes on to talk about, of all things, index cards. I was like, “Yes, exactly.” It turns out that plenty of successful people use simple index cards to turn off their rehearsal loops and get things done. But the point isn't cards, it's that non-externalized tasks deplete our brain energy through the “rehearsal loop” mechanism described by Levitin and that you and I can't think clearly when we're wasting brain energy.


  1. I help my students to think more clearly by “going big on argument,” the first of the five things in the Non-Freaked Out Framework for Literacy Instruction Across the Content Areas.
  2. As reader and friend Chris Vander Ark reminded me after this post went live, David Allen, author of Getting Things Done, is credited by Levitin for the use of index cards in brain externalization.
  3. Interestingly, no one seems to respond hatefully to this simple follow up. At best, they get right back to me. At worst, I don't hear from them, and so I just follow-up again in a couple of weeks.


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