Think, for a moment, about one of your cherished childhood memories, one of those sepia-tinged recollections that you've repeated countless times. I've got some bad news: big chunks of that memory are almost certainly not true. According to scientists, the brain is a consummate liar, a bullshit artist of the first order. To remember is to fabricate.
Why is memory so inherently dishonest? To make a long story short, it's now pretty clear that the act of remembering a memory changes the structure of the memory itself. (This is known as memory reconsolidation; Freud called it Nachtraglichkeit, or "retroactivity".) My favorite analogy is that, while we used to think of episodic memory as a "save" function in the brain (the hippocampus is the hard drive) we now know that every memory is really a "save as". To recall is to create a new file, and instantly overwrite what came before.
Obviously, this has big implications for the veracity of memory. It shows us that every time we remember anything, the memory is altered in the absence of the original stimulus, becoming less about what you remember and more about you. So the purely objective memory is the one memory you will never know. And the more you remember a memory, repeating it to yourself and others, the less honest that memory becomes.
But wait, it gets worse: according to a new PLOS One paper by German researchers, a bad night of sleep can make you even more dishonest than usual. While it's long been known that we make many of our memories while dreaming - this is why it's so important to get a good night sleep after studying for a test - it turns out that sleep deprivation causes us to make up memories.
The scientists conducted a rather sadistic experiment, forcing people to stay awake for up to 44 hours at a time. The end result? The insomniacs were much more likely to develop false memories. (As Freud pointed out, the most dangerous aspect of false memories is that they feel true.) The good news, though, is that there's a cheap and easy cure for such unintentional lies. When people drank a cup of coffee just before they recalled the memories, the dishonesty disappeared. Caffeine is a truth serum.
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Two quotes on memory:
"These scenes. . . why do they survive undamaged year after year unless they are made of something comparatively permanent? ---Virginia Woolf, "Sketch of the Past"
"Has it ever struck you. . . that life is all memory, except for the one present moment that goes by you so quickly you hardly catch it going? It's really all memory . . . except for each passing moment." ---Tennessee Williams, "The Milk Train Doesn't Stop Here Anymore"
Jonah Lehrer's analogy to explain the way memory is stored, recalled and presented is excellent!
It casts clarity on problems psychoanalysts have always struggled to understand and analyse.
A very fine analogy indeed.
I second the praise of the computer save analogy... that's an easy way to think about a complex topic
it's to wonder where is the truth, but in a more practical sense, i would like to know if all the memories are altered by insomia in a regular way: are the semantic memory as fragile as the biographic memory?
So, Ted beat me to it on Woolf, but at least it's from another work.
Re-reading The Years recently with not unpleasant internal distractions thinking about shrewd creative-neurological observations made by Jonah in his first book, and how many brainlife insights are observed by the various Pargiters in Woolf's capable hands. Memory, when covering a 57 year timeline, is indispensible, but unreliable. The characters are caught up with memory lapses, conflicts and overlaid images. Unlike the sleep-deprived fabulators, Woolf's men and women are in doubt about their memories. Old age is blamed, as is the boredom of being in dull company.
Sounds as though we need a cortical version of a Google cache. Caffeine can't be the only hope.
Have studies been done comparing highly visual subjects vs others who have a difficult time recalling details? How might verbal recall compare to sketching or acted out recall Eleanor Pargiter looks at the sky which is overlaid with hundreds of pictures - which memory will come to the front, and why?
Apologies to Luci, et. al., Please attribute this to my insomnia , and no coffee: I think I was going to quote Richard the Third, but I can't remember.
You state:
"while we used to think of episodic memory as a "save" function in the brain (the hippocampus is the hard drive)," when you must be aware that we have known for decades now the fundamental truth that memory is distributed and not "held" in the hippocampus more than a night or two.
Furthermore, you claim that "a bad night of sleep can make you even more dishonest than usual." The intentionality implicit in this statement and others in the post seriously misstates what participants in these studies do - they are instructed to report veridically and try to do so.
So the test subjects didn't enjoy a steaming cup of adenosine antagonist, just a plain old 200mg caffeine pill (or placebo).
False memories are real. Capturing the mechanisms is the tricky part.
My only quibble with PLOS, PubMed and Research Blogging is that it impacts the time spent with Woolf, Bulgakov, Joyce, Brin and so on. I don't remember caffeine in Richard III. Must find out. There is always sufficient temporal space alloted for the Frontal Cortex.
In this study, subjects were given lists of words that suggested a theme--"coal" and "night," for example, suggested the idea of "black." Sleep-deprived subjects were more likely than well-rested ones to say that "black" had been given in the original list, when in fact it had not been.
So the content of the false memory was suggested. The study showed that sleep-deprived people have a harder time remembering the difference between an implied association ("black") and an explicit input ("coal," etc.). But as far as I can see, this study doesn't really show subjects spontaneously generating false memories out of their own imaginations.
Are there studies of false memories which are not suggested? Or is suggestion always a factor in producing false memories?
I think the point to keep in mind about memory is that if you don't over-rely on it, it serves as a pretty good mirror of the real world. For example, I couldn't tell you right now how to drive to the house I grew up in; if I tried, I imagine I might generate false memories of the route and directions. But the last time I went back for a visit I found the way easily. No doubt my memory was helped by the sight of old landmarks.
This scientific validation should set the minds of memoir writers at ease. No more agonizing over what Truth is. Truth is whatever you remember it to be, and who can argue, because we all remember differently.
Seriously, in my book (I did write one, and this is in there), truth is whatever we remember and believe it to be, because that's what shapes our lives and who we are. How nice to have scientific verification.
So how do you remember anything you've ever learned? The fact is we all remember many things quite accurately and use them every day. That doesn't mean you remember everything accurately and we all know some people have better memories than others, even for that distant past stuff.
thankss
Very interesting article. I guess sleep deprivation can hurt you in many ways.