Mar 14 2008

False Memories in the Courtroom and Elsewhere

Scientists and skeptics are keenly aware of the nature and limitations of human memory (or at least they should be). While so-called “believers”, and the public at large, generally put unjustified faith in the accuracy of memories, especially their own. This often constitutes the gulf that separates believers and skeptics on many issues.

Many people remember being abducted by aliens or seeing ghosts. Advocates of dubious medical treatments often site stories of people who were apparently cured by the treatments. The stories often seem very compelling, the facts all line up, the conclusion seems obvious. Yet skeptics will easily shake their head and say, “I just don’t believe it.” This frustrates the believers no end. How can the skeptics dismiss what so many people have experienced, they wonder.

The reason is simple – human memory is incredibly unreliable, and most people grossly underestimate the extent to which their own memories can be altered and fabricated.

The issue is of very practical importance in the courtroom. Eyewitness testimony is still commonly relied upon as key evidence in trial, including murder trials. This is despite the fact that for years there has been evidence from memory researchers that eyewitness testimony is unreliable. Now another assumption of the courtroom regarding memory has apparently fallen. New research suggests that the testimony of children may be more accurate than that of adults – the exact opposite of prior assumptions in the courtroom.

Researchers Valerie Reyna and Chuck Brainerd of Cornell University have conducted research that shows that children are less likely to produce false memories than adults. They have developed a theory of memory to explain this apparent paradox, a theory which is concordant with my reading of other neuroscience research in this area. They propose that that humans actually store two kinds of memory, which they call verbatum trace and gist trace. Verbatum trace memories are a more accurate and unaltered version of the details of what was experienced. Gist trace memories, however, focus on the meaning of the memories and not on the details.

Other researchers, studying true vs false memories with fMRI scanning, show that different parts of the brain are involved in retrieving detailed (verbatum) memories from emotional (gist) memories and also that there is different activation with true vs false memories in some parts of the brain but not others. What this means is that there is an underlying neuroanatomical correlation to what the memory experts are discovering clinically. Our brains store different types of memories that serve different purposes – one for detail, and another for emotion and meaning.

So why would children have more reliable memories than adults? Because their meaning-based gist memory is less well developed. Their brains are less cluttered with wisdom and meaning, so their memories are more concrete and therefore detail oriented. They are therefore less prone to false memories, because false memories begin with the desired meaning (a gist memory) and then backfill the details as necessary.

While I buy this explanation, I think it needs to be modified. In the 1980′s there was an epidemic of false child abuse cases brought to court, largely on the false testimony of children. Upon review of video-taped testimony it was determined that much of the testimony extracted from the children was coerced by interviewers who were either poorly trained or excessively eager. The children, in retrospect, were largely telling the adults what they thought the adults wanted to hear – even to the point that they made up elaborate tales about satanic cult abuse, cannibalism, and other atrocities. The difference is that the children did not necessarily believe the tales they were telling – they weren’t false memories they were just encouraged fantasies.

That aside, when not encouraged to fantasize, children give more verbatum-based testimony than adults. An adult is more likely to remember that a man accused of murder is a threatening criminal, and then fabricate entire details to support that gist memory – like that he brandished a weapon and made threatening comments. These false memories for details that our brains happily invent to support and amplify our meaning-based memories are indistinguishable to us from accurate memories.

What does all this mean? In the courtroom it means that there is further evidence to be suspicious of eyewitness testimony, especially if it is contradicted by objective evidence. Also, witnesses are not either lying or telling the truth – they may be honestly relating a false memory. It may be possible to encourage witnesses to access their verbatum memories rather than their gist memories – for example by asking emotionally neutral questions, and encouraging them to focus on details rather than emotions, and to put themselves in the events they are trying to recall.

For skeptics this is further evidence that memories can’t be trusted. It nicely helps explain why so many people “remember” a standard alien abduction scenario under hypnosis. They have or are being given the gist memory – the abduction – and then are encouraged to back fill the details. The brain happily complies – voila: a false memory.

But there are more subtle manifestations as well. As a physician I have learned to be highly skeptical of the details that patients give me as part of their medical history. I have learned to triangulate – ask multiple questions from different angles, questions that are designed to encourage memory for details and to appear neutral (at least during the history taking) regarding the meaning of the details. It is well known that patients will tend to simplify stories to enhance their apparent meaning, or that they will link the onset of symptoms to discrete events. Because we have an historical record (the medical chart) that we can compare the patient’s history to, physicians will typically see the process of false memory formation for themselves.

Here is a typical scenario: A patient reports to me that her neurological symptom began after she fell and hit her head six months ago. I will often then ask a detailed question without indicating why I am asking (although it is often obvious) such as – did you have this symptom last year at this time? Patients will often give me conflicting reports when I do this, so then I know I have to ask more questions in order to fill in the real picture. Or, I may read her records and see that she complained of the symptoms two years ago to her primary doctor, despite now claiming that they did not occur until she hit her head six months ago. The patient is not lying, the details of their memory have simply been altered subconsciously to enhance the meaning of a gist memory – perhaps that they were doing well, without any problems, until they had the injury.

A similar thing can happen in response to a treatment the patient believes helped them. They may report that their symptoms were continuous and unremitting, and then shortly after they took the miracle treatment their symptoms completely resolved. However, it’s possible that their symptoms come and go at random and have no real relationship to the treatment they took, or perhaps the symptoms were going away on their own before they started the treatment. But the patient has a gist memory – this treatment cured me of my symptoms – and the details of her memory morph over time to enhance the meaning of that memory.

This is one reason (among others) that anecdotal evidence is not reliable. Scientific data is recorded as objectively as possible under controlled conditions and in detail. Anecdotes often rely upon memory -and the reason people remember and tell others their anecdotes is because they have meaning to them, and that meaning trumps the accuracy of the details.

As the psychology and neuroscience of memory advances it is moving more and more in the direction of concluding that memories are malleable, they can be fabricated, and human memories appeared to have evolved more to tell us a meaningful story than to faithfully record details. Hopefully this message can be beaten into the public consciousness. As the ancient Greeks said – “know thyself.” Humans would do well to understand the nature of being human. It will help us administer appropriate justice in the courtroom. It helps scientists conduct better research. It helps clinicians take more accurate medical histories. It can help everyone in their everyday lives.

And it can help skeptics explain why we are so skeptical.

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23 responses so far

23 Responses to “False Memories in the Courtroom and Elsewhere”

  1. pecon 14 Mar 2008 at 10:55 am

    “it can help skeptics explain why we are so skeptical”

    Ok, but what explains why you “skeptics” are only skeptical of things that defy materialism? If you’re so skeptical, why are you so easily convinced that cancer will be cured and intelligent machines will be built, within the current materialist framework?

    A genuine skeptic looks at the evidence, regardless of what philosophy it seems to support.

    Currently, most of the organized, activist, so-called “skeptics” are really promoters of a particular ideology.

    Most of us have some emotionally-based preference for one ideology or another. Skepticism is a daily struggle, and can never be maintained perfectly. The important thing is to be aware of our personal biases.

    The organized “skeptics” do not seem to have much awareness of their ideological preferences. They dream of a future where science has conquered nature, and has created a peaceful and disease-free utopia. They may not expect to see that utopia personally, but hope that their children or grandchildren might.

    “Skeptics” fear that if any aspect of alternative science turns out to be true, philosophical chaos will result. This fear may have a powerful subconscious influence over supposedly scientific and objective beliefs.

  2. daedalus2uon 14 Mar 2008 at 11:25 am

    pec, so far there is no evidence that is not explained by what you call materialism. Show us some that can’t be and we skeptics will look at it.

    If any part of “alternative science” is shown to be true, skeptics will adopt it and it will become a part of mainstream science. Everything else in mainstream science is pretty reliable. “Alternative science” won’t become a part of mainstream science unless and until it is shown to be reliable too.

    Skeptics are just as skeptical of material explanations as they are of everything else. Material explanations however have data to back them up. Non-material explanations don’t.

  3. Jim Shaveron 14 Mar 2008 at 11:34 am

    pec:

    BALONEY.

    Skeptics do not fear that “alternative science”, whatever that is, will turn out to be true, no more than skeptics have “faith” in their naturalistic paradigm. These are just pitiful excuses for continuing to support ideas that have been proven (in a scientific sense) wrong.

    Other than that, daedales2u pretty much covered it.

  4. Aaron Son 14 Mar 2008 at 11:46 am

    Jim Shaver: right. By why do you bother replying to our local “village idiot”? His claim that materialists and scientists like Novella are 100% confident in what they assume true has been shown to be a straw-man at least 15 times between this and last month. He bring it up every time, and every time someone points out what daedales2u basically said, often Novella himself.

  5. Blair Ton 14 Mar 2008 at 12:13 pm

    Not that I want to pile on pec comments – but when he says “what explains why you “skeptics” are only skeptical of things that defy materialism?” – what does that have to do with this piece?

    It seems to me none of the examples Steve gives involving faulty memory have anything to do with defying materialism. Murders, child abuse, and medical histories all fit within materialism. Heck, as unlikely as it may be, alien abduction also fits with materialism.

    Back to the memory issue though – I just saw a great demo of faulty memory on TV last night. They had someone perform a magic trick and ask you to try to spot anything unusual. While he does the trick a bright yellow happy face ballon floats over his shoulder. I didn’t see it and when they ran the clip a second time and pointed it out – I had a very hard time believing that it was the same clip.

    The show is available on the web, but it looks like is may only be accessible from Canada:
    http://www.cbc.ca/projectx/watch.htm

  6. James Foxon 14 Mar 2008 at 12:28 pm

    Another part of the mix involves emotion and it’s ability to change memory and perception…
    http://www.talkleft.com/story/2003/02/16/737/97650

    “Another presenter was Harvard pychologist Richard McNally, who
    tested 10 people who said they had been abducted, physically examined and sexually molested by space aliens.
    Researchers tape-recorded the subjects talking about their memories. When the recordings were played back later, the purported abductees perspired and their heart rates jumped.

    McNally said three of the 10 subjects showed physical reactions “at least as great” as people suffering post traumatic stress disorder from war, crime, rape and other violent incidents. “This underscores the power of emotional belief,” McNally said. “

  7. James Foxon 14 Mar 2008 at 12:38 pm

    More information about Elizabeth Loftus PhD.
    http://faculty.washington.edu/eloftus/Articles/psytoday.htm

  8. nowooon 14 Mar 2008 at 12:38 pm

    Spelling correction: it’s verbatim not verbatum.

  9. Roy Nileson 14 Mar 2008 at 12:50 pm

    “Humans would do well to understand the nature of being human. It will help us administer appropriate justice in the courtroom.”

    Unfortunately, in the adversarial system used in most American Courts, the nature of being human is understood more by attorneys who want memories manipulated than by jurors who end up with snippets of memories that witnesses are allowed to present. And these snippets are valued more for their emotional content than the factual.
    The adversarial system and its peculiar rules of evidence results in a manipulation of memory that is much more egregious than anything poor investigative practices can do – but of course the poor investigative work is part and parcel of the whole manipulative process.

  10. azinykon 14 Mar 2008 at 1:03 pm

    I should be congratulating Dr. Novella on his excellent post, but here I am, responding to “pec”, instead.

    pec wrote: “Ok, but what explains why you “skeptics” are only skeptical of things that defy materialism?”

    Have you stopped beating your wife? pec’s question is based on a false premise. We’re skeptical of a lot of things that have no supernatural element: UFOs, cryptozoology, perpetual motion machines, pyramid schemes and gambling systems, and many herbal medicines. Those ideas can be entirely materialistic, and still bogus.

    Reading what the other commenters have to say, I realize now that responding to pec at all is a waste of time, because he never learns, and never changes his tune.

  11. Roy Nileson 14 Mar 2008 at 1:57 pm

    James, I have been a professional investigator, both as a Federal agent and private investigative agency operator for over 45 years. Investigations are manipulative if used for that purpose, and that’s exactly how attorneys use them. That’s also how prosecutors use them as a reaction to anticipated defense usage. That’s how police department’s often use them for a myriad of reasons, especially with the deficiencies of the justice system always in mind.

    Your expression of what you believe the adversarial system to be is terribly naive. It’s a simplified version of what it’s supposed to be in theory, but the theory has not been borne out by the practice.

    This is not the place to go into great detail as to what, why and how it has gone wrong, or how to fix it (but advocates of the inquisitorial system and administrative law systems are making headway). My point was that suppression of memory is rampant in our system, and accurate or not, what is actually remembered in complete and relevant detail almost never gets to a jury.
    Part of an advocate’s job is to suppress the truth that will do harm to his client, and it’s done in part by preventing a witness from saying what he remembers, even if by chance he is able to remember it accurately.
    Read an attorney’s handbook about the art of cross examination, and see that it’s devoted more to making an honest witness look like a liar than outing the real thing.

  12. Roy Nileson 14 Mar 2008 at 2:45 pm

    An obvious response to my contentions would be to ask, if the system is so broken, why does it even work at all, or juries actually come to the right conclusions much if not most of the time?

    I’d respond that a collection of twelve people, no matter how much you try to sort them out and stack the group with fools and bigots, can be remarkably good at picking up clues just by watching all the participants in a trial and by reading between the lines, so to speak.

    And they almost always apply their own real life experiences to the situation to search for a ring somewhere of the truth. Their powers of inferential reasoning are in the main quite remarkable.

  13. Sastraon 14 Mar 2008 at 3:09 pm

    I remember reading once about a series of experiments designed to test the memories of children and see how easily influenced they were by expectations. The teacher announces to the class that they are all going to listen to a talk by a “clumsy man.” The speaker then comes in and gives a brief talk on some neutral subject (traffic safety?) He is careful to do nothing unusual. Class resumes, and there is no opportunity for the kids to confer about what they just saw.

    Later, the children are taken one by one to be interviewed on the speech. They are asked “tell me about the talk you heard today.” In most cases, students then volunteered descriptions of the speaker which included things like “he fell down when he came in” and “he kept knocking stuff over.” Many of them reported the same semi-specific sounding non-existent event. To someone unaware of the experiment, it would seem highly unlikely that nothing unusual had gone on, and the man had not tripped or knocked over anything at all.

    Now, is this a case where their memories were changed by their prior expectations? Or is this a case where the children thought there was something special they were supposed to say about the speaker, and, although they noticed nothing “clumsy” about the man, they were giving the adult what they thought was wanted? As I recall, the study drew the first conclusion, but I can’t remember if they considered and rejected the second, or if it wasn’t addressed.

    Does anyone else remember reading about this study? I’ve always thought of it when people talk about how ‘reliable’ children’s memories are.

  14. Roy Nileson 14 Mar 2008 at 4:12 pm

    James, my own experience includes having been assigned as a hearings officer in numerous administrative law hearings that were and are part of the Federal regulatory system. There were flaws of course, many of which have been dealt with since my days in that service.
    I was often the sole judge, who interviewed witnesses, sometimes with the help of their representatives, and sometimes not. And there were times when representatives became advocates to such an extent I had to have them removed from the case. In short, I and other hearings officers were given too much power at times, and of course such power was subject to abuse. (I got a bit too much satisfaction from exercising shyster control, for example.)

    Part of the problem was and continues to be the shortage of trained personnel who can operate with the same degree of professionalism as those in the more lucrative areas of the general profession can operate.
    But I can’t agree that there is more likelihood of corruption in the inquisitorial than the adversarial systems, if that is one of your main criticisms. It’s a lot harder, for example, to corrupt a panel of judges (often if not usually the case in European systems) than an occasional political appointee with the same powers and with unspoken obligations to a number of people who arranged for him to have those powers.
    And we are moving more in the direction of good administrative law courts (almost the same difference as inquisitorial operations) in many jurisdictions. And look at the Health Court movement as an example, and certain successful drug court operations. There is some impetus toward more professional juries in some circumstances, there is a loosening of the rules against “hearsay” evidence.
    Of course attorneys and others with a vested interest in maintaining things as they are, some of whom are true believers and some not, but most of whom would be fish out of water anywhere else, will often resist any changes to the death. And they populate our legislatures which have the ultimate power to make such substantive improvements.
    Nevertheless change is occurring, and things like the Simpson case (or cases) and increased media coverage of such cases are giving it a certain impetus.

  15. Steven Ron 14 Mar 2008 at 4:27 pm

    Replying to Pec’s first post:

    First of all, for something to be evidence that would mean that their is some sort of interaction in the universe as we know it, other wise there would be no possible way to know about it(making shit up doesnt count as “knowing”). So if something interacts with matter and energy and can be measured as such, it automatically falls with in materialism. there can be unexplained evidence, but one can not have evidence for something that does not interact with the physical world. One can draw a conclusion that something paranormal exist from unexplained evidence, but then the question comes of how to prove, and disprove something that is non-materialistic. It becomes one large, logical glitch in the idea of something other than materialism.

    Let say for some reason people find the everyone has a soul, can measure it, and identify it in various ways. This would then become part of the materialist paradigm because it would be a measurable part of the universe.

    Pec said: “The organized “skeptics” do not seem to have much awareness of their ideological preferences.”

    I semi agree with you on this. I wouldn’t be so harsh, but I have meet many hard headed people who describe them selves as skeptics. In fact, some of them are as bad, or worse than some of the “true believers”. I say I semi-agree, because it is unfair to group everyone who describes them self by a word, together.

    The majority of chiropractors believe in, or at least practice subluxation theory, while a small amount denounce it and do not practice it. A single word can have different meanings and inferences. In addition, a self description is hardly objective.

    So I guess we could say be skeptical about people who say they are skeptical. And even more important, ask yourself if you are are being skeptical about an issue.

    And that includes you Pec ;)

  16. Steve Pageon 14 Mar 2008 at 6:50 pm

    Isn’t a pec just another word for a male breast? Seriously folks, I think it’s time to stop feeding the troll.

  17. ajon 15 Mar 2008 at 2:51 am

    “The children, in retrospect, were largely telling the adults what they thought the adults wanted to hear – even to the point that they made up elaborate tales about satanic cult abuse, cannibalism, and other atrocities.”

    why would adults want to hear that from children?
    though it does sync with the news
    read through some of these stories:
    http://legallykidnapped.blogspot.com/
    &
    child sex abuse is big business
    http://www.chicagotribune.com/news/nationworld/chi-0512270176dec27,0,1632557.story

    and don’t poo poo ufos especially people who have mysterious implants

    man I love reading these comment its like “you seem to be misguided, my you know what is bigger than yours!” in a pseudo egghead kinda way

    great vague lawyer speak as usual Steve

    peace

  18. Steven Ron 15 Mar 2008 at 6:03 pm

    “…what they thought the adults wanted to hear…”

    It doesnt mean that is or is not what the adult wanted to hear, just that the childern are lead into thinking that the adult wants to hear a fantastical story, and the more elaborate twists and turns are slowly guided by the person asking the questions. Much like hypnotism induced memories, exept in the case of childeren, it seems both side are pyching each other out.

  19. Jackon 16 Mar 2008 at 11:34 pm

    Query: Are some kinds of memories more reliable than other, e.g., does HEARING something produce a more/less reliable memory than READING it?

    I have a very visual memory, so if someone tells me something, I’m far less likely to remember it because I can’t summon up the mental photo of the thing I read. Do other people have similar strength/weakness between visual/aural memories, which is usually stronger? If the answer is yes, then how does one determine it, and how to deploy it in, for example, a courtroom setting?

  20. Jackon 16 Mar 2008 at 11:39 pm

    Oh yeah, one more question:

    Why does it irritate doctors when patients keep notes on symptoms, dates, meds, BP/HR etc. where applicable? Because I often can’t remember exactly how I felt when, I’ve resorted to notes (partly to objectify the experience, and partly so my only answer isn’t “Gee, I don’t remember”) — but I’ve yet to find an MD who doesn’t roll his/her eyes when I consult my notes or offer them up.

    If only hypocondriacs keep notes, and if everyone’s memory is a crapshoot (see above), then what’s the answer? What’s a poor patient to do?

  21. eiskrystalon 17 Mar 2008 at 9:00 am

    Pec is the Neurologica pet.

    Steve throws him a bone every so often and he can’t resist coming out of his cave to play.

    He is housebroken and literate at least and I would miss his little rants actually, if only because the comments back at him are pretty insightful.

  22. Freddy the Pigon 18 Mar 2008 at 4:05 am

    Several years ago I heard interview of harmonica virtuso Larry Adler. He described a travelling in a miltary glider to perform at a military base in Nova Scotia during World War II. He described how much he enjoyed the serenity of the glider floating down to land after releasing from the tow plane. He then informed the interviewer that the other people who were travelling with have told him that he was travelling in the tow plane with them. He was able to clearly remember something that never happened even though he knew it had never happened. It was such a good memory that he had decided that the fact that it had never happened wasn’t going to stop him from enjoying the memory.

    A false memory can be just as strong as real one and nearly impossible to delete.

  23. [...] It isn’t always as simple as this, though. People you trust should still be doubted. They may not be lying intentionally, but they could still be mistaken. Human memory is very fallible. No matter how vivid a memory is to you, you can’t be sure that it is completely accurate. Your memory distorts reality over time. You may have a dream one night, but months or years later you could look back on it as though it was a real experience. A specific conversation you remember having with someone on one day, may in fact have actually occurred as several separate conversations, or maybe not even at all. Bits of memories get stored away, and related ones can merge together, you will remember this as one actual event, even though it never actually occurred as such. I don’t know much about the science of this, but Steven Novella (of SGU fame) does so, for more, read this. [...]

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