Your brain really is forgetting… a LOT

I’m currently reading Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday Life by Dr. Sandra Aamodt and Dr. Sam Wang. The enormity of the title notwithstanding, I’m enjoying the book, and ran across this rather amazing quotation:

There is good evidence that we “erase” and “rewrite” our memories every time we call them, suggesting that if it were ever possible to erase specific content, playing it back first might be an essential component.

This is a staggering statement. Consider the implications: when you recall a memory, you are capable of – and prone to – rewriting that memory in some form. I find this particularly fascinating in terms of teaching in a spiral method, something I continue to find effective and even critical in highly technical topics.

Take memory management in any programming language. It’s simply foolish to unload the truck on an unsuspecting learner, dumping out everything there is to know about memory management at one time, in one place, with little or no functional motivation. The better approach is to incrementally teach the topic, adding additional resolution, detail, and expansion only when new functionality is needed or additional understanding is required. In this way, you’re catering to the learner: each piece of information you’re unpacking is motivated by a need in that learner. This results in greater internalization of the information, and less information is categorized as “I don’t really need this. I’ll dump this.”

But with the quote by Aamodt and Wang, there’s another component at work here: earlier memories are potentially being rewritten as new learning takes place. This is intuitive, even: consider how often we mix up events that are very similar, but not the same. Have you eaten at Chuy’s 10 times in the last month (I’m about there)? If so, I’d suspect you’ll have a hard time distinguishing at which instance in 10 a certain conversation happened, especially without other mitigating details (a really close friend attended only one meal, or something particularly disastrous happened at another). Is it possible that the brain is trying to shove these similar events into one giant event, because we’re recalling an earlier (similar) event, replaying it, and rewriting it with the new one?

What this seems to suggest — and I grant that there’s a lot of theorizing and speculation happening, but what else is Radar good for if not some provocative thought — is that we must be extremely careful with context. When you recall an earlier mental model of something, and then augment that model, you may be rewriting the earlier model. In other words, you’re not just adding to an in-place model, but in fact replacing an earlier model with a newer, expanded one. So what are you doing to ensure the foundational models stay intact? Are you repeating the earlier model, and adding resolution? Or are you just writing about the “new stuff” without regard for the existing material?

I think most textbooks and technical books continue to heap on, assuming that pre-existing models remain in place. Foundational concepts never die, these books would assert (if not implicitly, then by the manner in which they teach). But perhaps those concepts do die! Perhaps this is why you may be adept at releasing memory or allocating memory, but would flail about helplessly at explaining what’s really going on. Is it possible that your original mental model has been overwritten, or even functionally replaced?

It’s an interesting thought. Context becomes critical, not just as a reminder of pre-existing material, but actually to ensure that pre-existing material is not lost altogether.

C’mon teachers, you must have thoughts on this… let’s hear them.