AG: Is there any way to distinguish a false memory from a real one?
EL: Without independent corroboration, little can be done to tell a false memory from a true one.
AG: Could brain imaging one day be used to do this?
EL: I collaborated on a brain imaging study in 2010, and the overwhelming conclusion we reached is that the neural patterns were very similar for true and false memories. We are a long way away from being able to look at somebody's brain activity and reliably classify an authentic memory versus one that arose through some other process.
I think the biggest giveaway from this article isn't how do you tell a false memory from the real one (because you can't), but the fact that you can have false memories at all. You can be 100% sure that something happened and at the same time be 100% wrong. This happened to me at least once and raises your humility - you never can be 100% right about something. Memory is malleable and it can play tricks on you.
One of my favorite facts is that you can be completely wrong about your current conscious experience, nevermind your memories. A few neat papers on this have been written by Eric Shwitzgebel ( http://www.faculty.ucr.edu/~eschwitz/ ) such as Why Did We Think That We Dreamed in Black and White? and How Well Do We Know Our Own Conscious Experience? The Case of Human Echolocation, or even scarier: Knowing Your Own Beliefs.
Funny, this brain imaging study from 2010 that she mentions, states in the abstract:
... Overall, true and false memories showed similar brain activation, but could be distinguished by this reactivation. This was true only in the early regions of the sensory cortex. ...
Hmm... At least for normal people memories of events that haven't happened in real life [but happened in sleep, video games, films, books; or just been imagined] are certainly distinguishable from memories of events that did happen in the real world. Even without external references. There's some metadata present that marks these memories as 'not recorded in the real world'. And even aside from that metadata, continuity and memory quality normally gives pretty damn good clues. No need to ask for 'independent corroboration'. <striked>And, if the opposite was true, you wouldn't be able to distinguish a memory from your last night dreams from a memory of a previous day. As simple as that.</striked>
"AG: How does this happen? What exactly is going on when we retrieve a memory?
"EL: When we remember something, we're taking bits and pieces of experience—sometimes from different times and places—and bringing it all together to construct what might feel like a recollection but is actually a construction. The process of calling it into conscious awareness can change it, and now you're storing something that's different. We all do this . . . "
The way I have expressed the matter before in discussions on Hacker News is that the problem with human memory is that read operations and simultaneously write operations. We think we are just recalling, but we are actively reshaping our understanding of previous events, true or false.
Forgotten what the article says? Not really. I've got an impression of it, and I didn't quite liked it. The whole concept of 'false memory' is very murky. There are no 'false memories' as such. There are just memories formed under different circumstances. That includes sleep and reflection.
And we just have to agree to disagree about last few statements in that article, on the page two.
Edit: I completely agree with you and with the statement that recounting something may change or reorganize the memory. It is just the concept of 'false' memories that I dislike. It is very poorly defined.
The concept is entirely fitting. The memory is false because you never save the entire experience as a memory fragment, instead you have bits and pieces and you reconstruct the rest when recollecting. If you reconstruct something that never happened or is factually wrong you are creating a false memory.
Can you be more specific, what particular parts of my comment are you finding to be idiotic?
I do have formal background in machine learning, computer science and had taken classes in neuroscience. I am a PhD dropout and I did original research in computer vision. I have every right to comment on articles written by specialists on 'false memories'.
I don't really understand why you bring up machine learning and computer science, since this is a completely different field. Classes in neuroscience would apply, but that's not all that impressive.
What I find to be idiotic is how trivial you make your contradiction, without any facts to back it up, adding computerish language to pander to the HN crowd ("metadata", really?), when it's extremely well established that people, with disturbing frequency, remember things that simply did not happen.
It's fine to disagree, but this sort of straightforward contradiction adds little to the conversation. It's the internet equivalent of Monty Python's argument clinic.
Who do you think are these researchers? More ML or more neuroscience?
///These disciplines are very relevant to understanding how memories are stored. More relevant than neuroscience in fact. Say, if you'd study modern computer vision, you will have some understanding about mechanisms in the works of human visual subsystem; about how humans memorize, recognize and associate images and image sequences. You will not have that understanding, if you'd study modern (basic) neuroscience.
You might have some ideas about how the brain might work from studying machine learning. But for the most part, it's going to be like learning about how fish swim by building a submarine.
Nope :) You might have some ideas about how the brain might work from bullshitters, like that 'false memory specialist' who gave interview to slate.
And you actually might learn some real stuff from people like these guys from UC Berkeley, who can recover video sequences by identifying an ML model with the visual cortex an then proceeding further and recovering unseen video sequences from fMRI of V4 area of neocortex.
... Now I only wish I could find a forum where a link to a research publication like this:
I don't understand what reconstructing visual experiences from the brain using scanning equipment has to do with the mechanisms of memory or the possibility of remembering things that didn't occur. They're completely different things.
The mechanisms of memory are not, as far as I know, well understood. However, it's well established that people can and routinely do remember things that did not occur. The why and how may be speculative, but the fact that it happens is not.
Hint: how can you explain that sometimes, the recovered image contains an object completely different from that seen by a subject of the experiment? [say, tree instead of a man]
Hint: can similar experiment be done with the part of the pre-frontal cortex responsible for associating visual memories with the condition in which these memories were formed? [imagined, dreamed, seen]
I have personally experienced that metadata getting messed up - one day I found myself with a very vivid memory of having recently, in real life, an anxiety attack while crossing a pedestrian suspension bridge across a river near my home. But there is no such bridge, and I could also not tell when exactly this had happened. The only explanation I have is that this was a dream that my brain somehow misfiled as a real experience.
In constrast, I otherwise never remember my dreams unless I wake in the middle of one, and even then they completely fade from my memory within minutes.
It is weird how in dreams everything changes, you are in your house but the house is from a movie you watched that day. And a distant family members lives with you in this house or something. And it all fits and seems incredibly normal. I always think of dreaming as brain defragmenting itself and your conscious picking up on it, trying to make sense of it.
"Then finally you go into therapy and crack through the repression barrier and out comes this pristine memory. But there really is no credible scientific support for that notion."
I personally had a repressed memory and it was uncovered in therapy. I am lucky that my mom is still alive and was able to verify the memories.
It's obvious to me from the snark in her tone like the word "pristine" and the rest of the article that she is a shill for defense attorneys.
False memory experts also work closely with interrogators and prosecutors to avoid contaminating testimony. Most district attorneys do not want to be involved in a fiasco like the Satanic ritual abuse cases.
Marijuana can also cause vivid recollection of forgotten memories. In my experience it's closer to reliving a moment than remembering; overall a very interesting experience.
I do believe that memories can be repressed and later recovered, but I also think that using recovered memories as evidence in a court of law is highly problematic. If a memory provides information that leads to actual forensic evidence -- the locations of buried bodies being a particularly dramatic example -- that can certainly be the basis for a conviction. But if it can't be corroborated at all, I would encourage a court to tread very lightly.
I think you and she disagree about what a "repressed memory" is. Maybe what you call "a repressed memory" she'd call conveniently forgotten. I think what she takes issue with is the idea that "in order to go on in life, you had to wall off this memory, because it would be too painful to live with." That you remembered a memory in therapy does not mean that you necessarily walled it off previously because it was too painful to live with. Or maybe you did, but she says there is not yet "credible scientific support." Maybe the research just hasn't been done yet.
Seems like her attitude towards "repressed memory" is an overly literal reaction against colloquially popular definitions of repressed memories. Perhaps her attitude is for the best because by not believing in the notion of repressed memories we prevent ourselves from having them? Still, isn't that some form of repression?!
"in order to go on in life, you had to wall off this memory, because it would be too painful to live with."
That was my experience. There were some embarrassing and traumatic events when I was a child. Throughout the rest of my childhood there were frequent reminders of the events. If I brought the events up later to my parent's they wouldn't acknowledge them, and they strongly discourage me from discussing it. These were significant events that led to my parent's divorce and I repressed them. When I recalled them later it was very emotional.
With regards to research and scientific proof... I don't know how you would prove it. How can others verify my experience. It's not easily repeatable. Even if it were repeatable... how could you prove something like that in an ethical way without traumatizing people.
The risk is that the same therapy techniques can "restore" memories that weren't there and didn't happen in the first place - and there are no known ways to distinguish the results to see if the memory was or wasn't real.
This should be pretty obvious. In basic terms, it would be extremely inefficient for the brain to store everything "directly." Meaning all memories are "reconstructions" to some extent and therefore inherently flighty given the dynamism of the brain. Said differently, it would be weird if the brain didn't take advantage of the very high-level abstractions we use in our day-to-day for the purpose of efficient memory storage.
Anecdotally, one time I re-played in my head an entire movie after I watched it (Astro Boy!) as an experimental exercise, and it was clear that as I was 'recalling' it, the line between "reconstruction" and "direct memory" was extremely blurry, and I could feel my own eagerness to fill in details that may or may not have occurred.
32 comments
[ 2.8 ms ] story [ 95.8 ms ] threadAG: Is there any way to distinguish a false memory from a real one? EL: Without independent corroboration, little can be done to tell a false memory from a true one.
AG: Could brain imaging one day be used to do this? EL: I collaborated on a brain imaging study in 2010, and the overwhelming conclusion we reached is that the neural patterns were very similar for true and false memories. We are a long way away from being able to look at somebody's brain activity and reliably classify an authentic memory versus one that arose through some other process.
... Overall, true and false memories showed similar brain activation, but could be distinguished by this reactivation. This was true only in the early regions of the sensory cortex. ...
ref: https://webfiles.uci.edu/eloftus/StarkOkadoLoftus_FalseMemor...
Edit: rm anecdotal evidence.
"AG: How does this happen? What exactly is going on when we retrieve a memory?
"EL: When we remember something, we're taking bits and pieces of experience—sometimes from different times and places—and bringing it all together to construct what might feel like a recollection but is actually a construction. The process of calling it into conscious awareness can change it, and now you're storing something that's different. We all do this . . . "
The way I have expressed the matter before in discussions on Hacker News is that the problem with human memory is that read operations and simultaneously write operations. We think we are just recalling, but we are actively reshaping our understanding of previous events, true or false.
And we just have to agree to disagree about last few statements in that article, on the page two.
Edit: I completely agree with you and with the statement that recounting something may change or reorganize the memory. It is just the concept of 'false' memories that I dislike. It is very poorly defined.
I do have formal background in machine learning, computer science and had taken classes in neuroscience. I am a PhD dropout and I did original research in computer vision. I have every right to comment on articles written by specialists on 'false memories'.
What I find to be idiotic is how trivial you make your contradiction, without any facts to back it up, adding computerish language to pander to the HN crowd ("metadata", really?), when it's extremely well established that people, with disturbing frequency, remember things that simply did not happen.
It's fine to disagree, but this sort of straightforward contradiction adds little to the conversation. It's the internet equivalent of Monty Python's argument clinic.
Who do you think are these researchers? More ML or more neuroscience?
///These disciplines are very relevant to understanding how memories are stored. More relevant than neuroscience in fact. Say, if you'd study modern computer vision, you will have some understanding about mechanisms in the works of human visual subsystem; about how humans memorize, recognize and associate images and image sequences. You will not have that understanding, if you'd study modern (basic) neuroscience.
And you actually might learn some real stuff from people like these guys from UC Berkeley, who can recover video sequences by identifying an ML model with the visual cortex an then proceeding further and recovering unseen video sequences from fMRI of V4 area of neocortex.
... Now I only wish I could find a forum where a link to a research publication like this:
* https://news.ycombinator.com/item?id=3031698 [Reconstructing visual experiences from brain activity evoked by natural movies]
Would not have an order of magnitude less interest than a link to a slate article like this:
* https://news.ycombinator.com/item?id=6349590 [ How Can You Tell a False Memory From a True One?]
The mechanisms of memory are not, as far as I know, well understood. However, it's well established that people can and routinely do remember things that did not occur. The why and how may be speculative, but the fact that it happens is not.
Here is the link again: https://news.ycombinator.com/item?id=3031698 [Reconstructing visual experiences from brain activity evoked by natural movies]
Hint: how can you explain that sometimes, the recovered image contains an object completely different from that seen by a subject of the experiment? [say, tree instead of a man]
Hint: can similar experiment be done with the part of the pre-frontal cortex responsible for associating visual memories with the condition in which these memories were formed? [imagined, dreamed, seen]
Indeed, there is an example in this thread that is perhaps even more on-point than the comment to which you replied.
In constrast, I otherwise never remember my dreams unless I wake in the middle of one, and even then they completely fade from my memory within minutes.
I personally had a repressed memory and it was uncovered in therapy. I am lucky that my mom is still alive and was able to verify the memories.
It's obvious to me from the snark in her tone like the word "pristine" and the rest of the article that she is a shill for defense attorneys.
Seems like her attitude towards "repressed memory" is an overly literal reaction against colloquially popular definitions of repressed memories. Perhaps her attitude is for the best because by not believing in the notion of repressed memories we prevent ourselves from having them? Still, isn't that some form of repression?!
That was my experience. There were some embarrassing and traumatic events when I was a child. Throughout the rest of my childhood there were frequent reminders of the events. If I brought the events up later to my parent's they wouldn't acknowledge them, and they strongly discourage me from discussing it. These were significant events that led to my parent's divorce and I repressed them. When I recalled them later it was very emotional.
With regards to research and scientific proof... I don't know how you would prove it. How can others verify my experience. It's not easily repeatable. Even if it were repeatable... how could you prove something like that in an ethical way without traumatizing people.
Anecdotally, one time I re-played in my head an entire movie after I watched it (Astro Boy!) as an experimental exercise, and it was clear that as I was 'recalling' it, the line between "reconstruction" and "direct memory" was extremely blurry, and I could feel my own eagerness to fill in details that may or may not have occurred.