Fuzzy memories may be a search problem

For years, it's been thought that long-term memory holds much less detail about things we remember than short-term memory. However, new research from MIT suggests that longterm memories may not be that fuzzy, but are just harder to find. From Scientific American:
If our memories aren’t all that fuzzy, then why do we often forget the details of things we want to remember? One explanation is that, although the brain contains detailed representations of lots of different events and objects, we can’t always find that information when we want it. As this study reveals, if we’re shown an object, we can often be very accurate and precise at being able to say whether we’ve seen it before. If we’re in a toy store and trying to remember what it was that our son wanted for his birthday, however, we need to be able to voluntarily search our memory for the right answer–without being prompted by a visual reminder. It seems that it is this voluntary searching mechanism that’s prone to interference and forgetfulness.
Why Do We Forget Things?


  1. It is comparable to the problems encountered while looking for information on a search engine. Good article.

  2. Memory is an odd thing. I’ve heard all my life that our brains store memories of everything we’ve experienced, but if this is true, its an amazing concept. I’d imagine it would take all of Google’s computers to store the sensory input from just one person spanning a week or two, much less a lifetime.

    As far as recalling a memory is concerned, I know there are people out there that can scan a book and later, visualize the book and recall everything in its contents. They say that this skill can be learned by just about anyone, but I don’t believe that for a second. I’m sure those people are born with that ability and are just trying to convince people that they gained it through hard work and determination.

    One of the best ways I’ve found to recall a particularly difficult memory is to relax and place my mind in an alpha state. I read about this decades ago in a self hypnosis book and am able to do it pretty easily. I also do this when I’m studying for tests. I go to a quiet room, relax, do the alpha state thing and read the material which I’m being tested on. So far, this technique hasn’t failed me yet.

  3. I find it kind of unnerving that we’re hearing more and more from neuroscience types about how our brains fail to work as efficiently as computers in some respects.

    I always thought the assumption was that the structure of memory and processing in a computer system was based on our relatively lacking understanding of how the brain works. Like a sort of oversimplification. Are we now limiting ourselves by assuming the goal is to become efficient in the way we expect a computer to be?

    I don’t know – I guess it’s a serious philosophical question… but it seems like we may be wrangling ourselves into a corner by trying to get our brains to behave in a way based on something we created to badly mimic brain behavior in the first place. Or maybe that’s just the paradox of how knowledge develops…

    Shoot, my brain is starting to hurt thinking about this too much now.

  4. I had nearly perfect memory as a child, but my hubby had been conditioned to think he had none: his anxiety/stress reaction to being told “You can do better!” resulted in the opposite effect — he was convinced he remembered nothing!

    Five years on, he has convinced ME of his extreme memory defect, but now he has delayed-reaction eidetic memory (better than mine! bastard! ;) )

    So our new assessment is: it’s all in there, no matter who you are — the trick is the access algorithms!

  5. I don’t think that every detail from every sensory input we receive over a life time. I think the bits of information in our brains would be impossibly large. Instead, from what I’ve read from a few sources, our brains build, or weave, memories together from different pieces that is sure it remembers and fills in the rest, in a similar way it fills in the blanks with that infamous hole in the center of our eyes.

  6. I’ve always found that sensory stimulus like certain smells and sensations can trigger intense memories.

    There is a certain smell in my mother’s house that creates a haunting sensation of what my childhood “felt” like. When we open the boxes of Christmas ornaments, there is an almost visceral response to the smells and the feel of the tinsel.

    I am the youngest of many and when we all discuss our childhoods during holidays or reunions, my siblings don’t remember things that happened when I was two, and they are 7+ years older than me! Now that my son is two, I’m being very careful about what I do or say… I remember purposefully calling my older sister’s “boyfriend” by the wrong name when I was about two or three and causing a wonderful “little brother” moment. Haha!


  7. “Now that my son is two, I’m being very careful about what I do or say…”

    Absolutely! I taught my oldest son every cuss word in the book while playing Contra on my Super Nintendo. I was pretty young and fresh from the Navy, so I had a pretty foul mouth back then. It took my son, 3-4 at the time, saying the F-word in front of my mother in law to make me stop cussing.

    There’s no doubt, children are a product of their environment.

  8. …from this we may learn the ultimate essence that pervades wide spread ubiquitous all over the place..anybody want another beer?

  9. Tom Hale: the sensory bandwidth of a human being is on the order of 100Mb/s. Memories do not store raw data by any means, and the rate of storage of long-term memories has been estimated at one every three to five seconds. Plus, of course, you don’t store them when you’re unconscious, and even though you do store long-term memories in your first few years of life, you almost invariably lose access to them (why is debated, perhaps the massive neural trimming at around 2–3 years of age).

    Add it all up, and human long-term memory doesn’t need to be all that vast after all.

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