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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.

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  • http://www.megginson.com/blogs/quoderat/ David Megginson

    Interesting post — thanks.

    Animals are even more context-dependent than people. At puppy class 10 years ago, the trainer demonstrated by training a young dog to sit on command, until it could do it 100% of the time. Then she turned herself and the dog 90 degrees, and the puppy’s score dropped to 0.

    It turned out that the puppy had included the wall behind the trainer as part of the context for the action — when it saw a different wall, it no longer associated the command with the action, and had to relearn it.

  • Gwen

    I can comment on both the ‘overwrite’ function and ‘functional replacement’ of memory, especially in the context of a traditional classroom. There is a tradition of teachers having difficulty communicating particular concepts about the world that appear to run counter to the students’ everyday experience. Physics, in particular, has a long list of such concepts (momentum, gravity, force, friction, to name a few), but all fields have them.

    When a new concept is presented in a passive fashion, students (dutifully) try to learn the material by linking it with what they already know – generally, this is what we want! Unfortunately, what they already “know” is often functionally useful, but uninformed (ice is just slippery – duh). They can sometimes recall the fundamental fact from class correctly, but may have functionally replaced it with a new concept+old paradigm, or will actually recall the old paradigm as the fact taught in class (rewritten).

    Happens all the time. The key seems to be in requiring students to make explicit connections between the fundamentals, new material, and their own experience at the same time.

  • Roger Weeks

    If you haven’t listened to the “Radiolab” podcast, I suggest you do. They cover topics like these each show.

    Season 3: Memory and Forgetting
    http://www.wnyc.org/shows/radiolab/episodes/2007/06/08

  • https://www.twitter.com/gsempe gsempe

    Very interesting.
    You make me a new buyer of the book.

  • http://aprilraines.digitalnovelists.com/ April Raines

    umm, ya. I recall in third year cognitive psych – this was in 1996 or 97 – discussing a new police interrogation technique based on letting the person do free recall. The reason was that if you asked any kind of leading question – ie. ‘What colour was the car?’ when they hadn’t mentioned one – the person would fill in the details. If the interrogator says ‘Did you see a blue car?’ odds are you’ll say yes, even if you aren’t totally sure, and then by the time you get to the witness stand you honestly believe/remember seeing a blue car.

    And think about this point – those super smart folks, profs, geniuses and whatnot – often cannot explain the basics of things because it’s all melded together. The basics has become part of the whole and they can no longer separate out the pieces.

  • http://postlinearity.com gregorylent

    yet another idea that would find a higher understanding if neuroscience could begin to understand that memory is in the field, not the brain …

    the brain is merely the nearest physical correlate to that field, and all that is available to those of the consciousness-comes-from-meat persuasion …

    primitive science … ask a yogi

  • http://www.stapleton-gray.com Ross Stapleton-Gray

    For those who recall magnetic core memories, this comes as no great surprise.

  • http://friendfeed.com/ianf Ianf ⌘

    Makes a lot of sense.

  • http://blog.adaptivesoftware.biz Parag Shah

    One way students can keep the foundational model intact is by making notes, flashcards, or even a personal podcast (just for themselves) of core concepts.

    Everyone makes notes, but I am not sure if everyone makes notes of the core concepts they encounter so that they can revisit them to strengthen their foundational model.

  • ednz

    it would be interesting to examine the relationship between the re-’writing’ process and the changes in discourse over time

    by which i mean, as we recall, re-member, re’write’,
    i assume we re’write’ using the discursive (put simplistically =language) tools current at each episode of re-c, re-m, re-w cycle

    which in turn gives a sense of ‘endurance/historicity’ to the current (fleeting) discursive patterns

  • teachie

    brings up massive issues for education. What we teach is dependent on how many times the topic/concept is brought up and what else is included in the memory grab at each point.

    Thanks for this – going to use it in class when we discuss oral histories of people.

  • http://spiritsdancing.com/sdblog Hil

    I’ve recently read Roger Schank’s most fascinating book “Tell Me A Story: Narrative and Intellegence”, in which he suggests that in telling our everyday experiences we create not only stories, but also the memory structures that will contain the gists of the stories for the rest of our lives. What we don’t tell is forgotten.

    ” Gists are structured sets of events that function as a single unit in memory that can be transformed by a variety of processes and manipulated for a particular purpose, A gist is a dynamic entity that can change or be replaced over time by adding or deleting details in subsequent tellings. We don’t recall the words we have added, although sometimes certain words and phrases do become an important part of the story. We do, on the other hand, recall the concepts we have added so that after retelling a gist in a certain way, with certain details left out and others emphasized, with some truths deleted and other nontruths added in, we have difficulty recognizing what actually happened. The only things we remember are the gists that we access. Accurate memories, then, are elusive at best”

    There is much about about memory in his book, and overall the book is about how we learn.

  • Bill

    A spiral approach to teaching, exactly as described by McLaughlin above, is an old but necessary approach. See The Unschooled Mind by Howard Gardner for the amazing loss of learning in even just weeks.

  • http://www.get-sorted.net/ Catherine Cantieri, Sorted

    What a fascinating article, and what great comments! I’m really intrigued by the idea that we are essentially upgrading our memories every time we access them. Great for building knowledge — maybe not so great for witness testimony and that sort of thing.

    Honestly, I’m just jealous of someone who can eat at Chuy’s 10 times in a month. (Former Austinite who misses the food almost as much as I miss my friends.)

  • Boris

    Learning new concepts can be reinforced by matching it with experience. But mismatches of new concept + old paradigm, as Gwen has put it, can be inhibited perhaps with some examples that are counter intuitive to the old paradigm, therefore rewriting it.

  • http://blogs.msdn.com/alexj/archive/2009/04/29/interesting-reads.aspx Alex James

    Brett,

    That is a fascinating read. One that has ‘surface validity’ for me. Certainly explains why the older I get the better my childhood seems!

    Alex

  • Ciaran

    Does this also apply to “give a man a fish, teach him to fish”? Is it only factual information that gets rewritten like this or does it apply to deductive type learning too?

  • miffed

    The enormity of the title notwithstanding…

    enormity: “an outrageous, improper, vicious, or immoral act”

    enormousness: “The state of being enormous.”

  • http://www.medyum.gen.tr/ medyum

    When a new concept is presented in a passive fashion, students (dutifully) try to learn the material by linking it with what they already know – generally, this is what we want! Unfortunately, what they already “know” is often functionally useful, but uninformed (ice is just slippery – duh). They can sometimes recall the fundamental fact from class correctly, but may have functionally replaced it with a new concept+old paradigm, or will actually recall the old paradigm as the fact taught in class (rewritten).

    Happens all the time. The key seems to be in requiring students to make explicit connections between the fundamentals, new material, and their own experience at the same time.

  • http://www.hikaye.biz hikaye

    A spiral approach to teaching, exactly as described by McLaughlin above, is an old but necessary approach. See The Unschooled Mind by Howard Gardner for the amazing loss of learning in even just weeks.

  • http://www.sskbank.com ssk

    brings up massive issues for education. What we teach is dependent on how many times the topic/concept is brought up and what else is included in the memory grab at each point.

    Thanks for this – going to use it in class when we discuss oral histories of people.

  • http://www.telefondinleme.org telefon dinleme

    Learning new concepts can be reinforced by matching it with experience. But mismatches of new concept + old paradigm, as Gwen has put it, can be inhibited perhaps with some examples that are counter intuitive to the old paradigm, therefore rewriting it.

  • http://www.medyum.org medyum

    this is very nice blog,thank you for all