Dec 09 2013

False Memory Fundamental

It is now well established in psychological research that humans can form false memories – memories for events that never occurred. Further, these false memories are indistinguishable from genuine memories. Questions remain, however, about the neuroanatomical basis of false memories.

One potential window into this question are subjects with so-called “Highly Superior Autobiographical Memory” (HSAM).  HSAM itself is a fascinating topic – there are people who can remember many details about specific days in their past. You can ask them, what were you doing on December 9, 2012, and they can think back and tell you, “it was raining and I forgot to bring my umbrella, and I was late for work.” For details you can check, like whether or not it was raining on that day, their details check out.

A new study explores whether or not you can generate false memories in people with HSAM. This may tell us something about HSAM and false memories.

They used standard false memory tests. In one test you show the subject a list of words that all have a theme, for example words that all relate to sweet foods. You then show them a list of words and have them choose which words they can confidently remember from the previous slide. Among the new list of words is “sweet”, which was suggested but never listed in the original set of words (called a “lure word”). A significant number of people will have a false memory of seeing the word “sweet” on the previous slide.

Another false memory test is to suggest an experience that someone never had, by describing it in vivid detail. At a later time some subjects may remember the experience as if they had it themselves – they have personalized the memory.

Yet another study type tries to implant misinformation by asking suggestive questions about pictures that were recently viewed.

The question is – do subjects with HSAM form false memories the same way non-HSAM people do? Does the mechanism of their HSAM protect them from false memories?

The answer – no. The study found that:

HSAM participants and controls were both susceptible to false recognition of nonpresented critical lure words in an associative word-list task. In a misinformation task, HSAM participants showed higher overall false memory compared with that of controls for details in a photographic slideshow. HSAM participants were equally as likely as controls to mistakenly report they had seen nonexistent footage of a plane crash.

So overall the HSAM subjects were as or more susceptible to false memories as typical controls.  What does this say about HSAM and false memories? That’s a good question that will require further research.

What we know now about HSAM is that people with this heightened autobiographical memory do not necessarily have enhanced memories for other types of information. We also know that they have increased white matter connections in those parts of the brain carrying autobiographical memory. It is not yet known if they have HSAM because of these increased connections or if they developed increased connections because they developed HSAM.

Regarding false memory, it is believed that they come into play during the reconstructive process of memory. Memories are not so much recalled as reconstructed. Every time you remember something you are reconstructing the memory from various details and themes stored in your long term memory. To construct the overall memory from these parts, and it is probably during this process that false details creep in.

Your brain tries to construct a consistent, plausible, and emotionally gratifying narrative. The details support the overall narrative, but they also can be created or morphed to comply with the larger themes of the narrative. If the theme of the words you just saw was sweetness, then it is likely that the word “sweet” was among them. That mugger was menacing and dangerous, so he probably was holding a gun.

What this study suggests is that those with HSAM may have superior memory for autobiographical details, but they still have to reconstruct memories from those details and this reconstruction process is just as flawed and susceptible to false memories as people with more typical memories.

Conclusion

Understanding memory is critical to metacognition – understanding the process of thought itself. We rely every day on our memories, which are highly flawed and susceptible to distortion. In casual everyday interaction, most people I meet have a dramatic overconfidence in their own memories. They feel that if they can clearly or vividly remember something, it must be accurate.

Meanwhile, psychological research shows that memory is constructed of many different parts – thematic memory, detail memory, event memory, autobiographical, source memory, and truth status, to give some examples. These types of memory can vary independently. We might remember, for example, that we heard something but forget whether or not it was true and where we heard it.

All of these memory components are ultimately woven together into a narrative in a reconstructive process. That seems to be the weakest link in the memory chain – the act of remembering itself alters the memory.

Our memories are evolving narratives. They change as we change, are updated as our knowledge and world-view change.

We cannot rely on our memories. The only solution is to reground your memories in objective external unchanging sources.

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11 responses so far

11 Responses to “False Memory Fundamental”

  1. tmac57on 09 Dec 2013 at 12:01 pm

    In casual everyday interaction, most people I meet have a dramatic overconfidence in their own memories.

    At least that’s the way you remember it ;)

    On a serious note,would you consider doing a series of short blog posts discussing the different parts
    ( thematic memory, detail memory, event memory, autobiographical, source memory, and truth status)
    of memory,maybe taking each one in greater depth ? I think that would be interesting.
    Also what does this mean for those who have to memorize detailed facts (such as doctors technicians,teachers) ? Do those types of memories suffer from the same type of malleability?

  2. Steven Novellaon 09 Dec 2013 at 12:21 pm

    Yes they do. However, you can solidify memories with repetition (studying) and then constant reinforcement (use). So I can remember lots of detailed facts when I use them on a regular basis (drug doses, etc.) but for stuff that I have not had to think about in years, I would not trust my memory.

    Essentially, brute force mental work is used to memorize lots of technical details. There is also now an emphasis on using checklists and other external reminders for critical information, and not rely on the brute force method.

  3. Didgyaon 09 Dec 2013 at 1:57 pm

    False memories are facinatiing. My wife is studing law and it is abhorrent the lack of understanding there is in the court system. After the debacle of ‘repressed memories’, one would think that this would be a common part of the court process involving wintness memory but according to my wife it is not. Just google it and see the gross amount of cases involved.

  4. Technogeekon 09 Dec 2013 at 3:05 pm

    It’s funny you should mention that, Didgya. I was at a talk given by Neil deGrasse Tyson last month, and he went into a brief digression about the times he got called up for jury duty. Once he got kicked off the jury for questioning the choice of units (specifically, referring to “7000 milligrams” in a drug trial), and once for pointing out that he wasn’t comfortable convicting someone solely on eyewitness testimony due to its unreliability. And once for saying that he was teaching a course that involved exploring said unreliability.

    (On an unrelated note, the same talk also touched on the infamous Face on Mars and how the higher-quality photo made it obvious that it was just simple pareidolia. I was seated a ways on the left side, and there were two screens set up to show photos: one to Tyson’s left, and one to his right. I found that when I looked at the screen all the way on the right, it made even the fully-lit photo look very much like a face. This really did a lot to emphasize how such an illusion could be created in the first place.)

  5. Fair Persuasionon 09 Dec 2013 at 8:12 pm

    How can regrounding your memories in external unchanging sources work? What are they? And how are they objective?

  6. MikeBon 10 Dec 2013 at 5:40 am

    This is exactly why I’ve come to distrust what is routinely called “psychotherapy,” the idea that one can talk one’s way toward “healing,” whatever that is, for it seems to me to be just emotionally-satisfying story-telling based on unreliable memories. Too bad there’s not more skeptical articles about that.

  7. BillyJoe7on 10 Dec 2013 at 7:24 am

    “How can regrounding your memories in external unchanging sources work?”

    Keep a diary.
    The diary is the external unchanging source.
    Periodically compare your memories with this unchanging source.
    Thereby you are grounding your memories in an external unchanging source.

  8. Sherringtonon 10 Dec 2013 at 10:48 am

    This is interesting work, and the results actually are in sync with another finding in false memory research: If people with “normal” memories use “deeper” processing to remember a list of words, they 1) remember more words than do people who use “shallow” processing and 2) remember more of the “lures” (words related to the words on the list). In other words, improving memory also makes the person more susceptible to false memories. An example of deep processing is evaluating whether the word is concrete (something you can physically touch) or abstract. An example of shallow processing is counting the number of vowels in the word. Of course, this is just one of the false memory paradigms; I do not know if this effect extends to others (such as the example with the photographs).

  9. KeithJMon 10 Dec 2013 at 11:45 am

    Fair Persuasion — imagine you were involved in the studies Steve mentioned. In a meeting with researchers you were shown a list of words with a general theme of “sweet,” and a researcher showed you some videos and also described video of a plane crash in very great detail (but didn’t show you the video). After leaving the office you take careful notes in a diary noting as many of the words as you could remember from the list, as well as your thoughts about the general theme. You also write down that the researcher vividly described a plane crash video, but only showed you videos of car crashes and puppies (or whatever).

    Before your next appointment with these researchers, you re-read your diary. You would probably have much more accurate recollection of your previous visit. That’s re-grounding your memories in an unchanged external source.

  10. Xplodyncowon 10 Dec 2013 at 9:24 pm

    Your brain tries to construct a consistent, plausible, and emotionally gratifying narrative. The details support the overall narrative, but they also can be created or morphed to comply with the larger themes of the narrative.

    Is this fact? Fascinating. What are some good sources to learn more about this?

  11. BEVERLYon 16 Dec 2013 at 12:56 am

    It’s true that we cannot rely on our memories because in reality memory is very prone to falsity. We can feel completely confident that our memory is accurate, but that confidence is not guarantee that a memory is correct.

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