Jun 30 2008

A Neurological Approach to Skepticism

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Comments: 7

A recent Op-Ed in the New York Times by Sam Wang and Sandra Aamodt called Your Brain Lies to You discusses many themes I have covered in this blog (here and here for example). The piece appears to be a preview of their upcoming book: Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday Life, but it is an excellent summary of many skeptical principles – namely that we cannot trust our memories.

They write:

The brain does not simply gather and stockpile information as a computer’s hard drive does. Facts are stored first in the hippocampus, a structure deep in the brain about the size and shape of a fat man’s curled pinkie finger. But the information does not rest there. Every time we recall it, our brain writes it down again, and during this re-storage, it is also reprocessed. In time, the fact is gradually transferred to the cerebral cortex and is separated from the context in which it was originally learned. For example, you know that the capital of California is Sacramento, but you probably don’t remember how you learned it.

This phenomenon is known as source amnesia – we remember facts but not necessarily how we learned them. In the context of our “evolutionary milieu” this was probably not a problem – it was better to dedicate brain power to remembering important stuff rather than how we learned them. Or, this could just be an unintended consequence of how the brain works. Either way, in our modern society, filled with misinformation, ideological distortion, pseudoscience, denial, revisionism, and simply bad information and unsubstantiated rumors spreading at the speed of the internet – it is critically important to know and remember where information came from.

I face this every day as a physician. I have a lot of medical knowledge in my head that I learned from years of classes, reading journals, and listening to lectures. For certain issues – controversial topics, recent changes to thinking, or those within my area of expertise – I can know the literature pretty well. But for much of my clinical knowledge I know the facts but not their sources. If I had to know even just the most critical literature on every single medical fact I would need to have about 10 times as much information crammed into my head. This is just not practical.

To compensate professionals in highly demanding areas like medicine rely upon what we euphemistically call our “ectopic brains.” I may not know everything off the top of my head, but I know where to look it up when I need to.

It turns out that knowing the sources for information is very important. Some fact in medicine are well established. But others were just guesses made years ago, but somehow became entrenched in established medical knowledge without ever being properly studied. Yet many physician may just remember both as disconnected facts. Recognition of this problem was part of the impetus for Evidence-Based Medicine (EBM) – going back and looking at the actual evidence for everything we think we know.

Source amnesia is not just a problem for information-intensive professions. Actually professionals typically have an infrastructure to deal with this failing of human memory – like searchable catalogues of published research. For everyday use, the internet is becoming humanity’s “ectopic brain” – which is overall a good thing, but it does displace the problem because you have to consider the source of the information you are reading on the internet.

The problem of source amnesia is far worse than just having a poor memory for the source of information, for the same process also leads to the loss of important bit such as whether or not the information is true. This leads to the fact that when people are told a claim and that the claim is a myth, days or weeks later they are likely to remember the claim but not that it was a myth.

Ack! This cuts right to the heart of what skeptics do – pointing out myths and misinformation. If we are not careful we actually can be increasing belief in the very myths we are trying to correct. Therefore, when Jenny McCarthy goes around spouting that vaccines cause autism, the scientific community can carefully correct all of her nonsense and misinformation, but the public is likely to remember, “didn’t I hear somewhere about vaccines and autism?” The damage is done.

What’s the solution? I think there are several ways to exploit this understanding of human memory. On a personal level I think that we need to consciously apply mental “metatags” to all information. For each factual claim (beyond the mundane everyday stuff) we need to make a mental effort to attach to that claim – what is the source, is it actually true, and how reliable is the knowledge. This is a mental habit we need to encourage and practice.

As a skeptic I find that I have learned to do this as a necessary strategy for remembering skeptical information. Skeptics are used to asking “is it true,” and so for each claim (especially controversial ones) we habitually focus on this question. As this habit evolves we next ask “how do we know?” Ideally for each such claim we would have mentally attached metatags, such as: Claim: vaccines cause autism; status: false – antivaccinationist myth; source: NeuroLogica blog summarizing extensive epidemiological research.

This then leads to the utility of having a skeptical “ectopic brain” on the internet – a convenient way to find and verify sources. Much of this infrastructure already exists. For example, most skeptics know that Snopes.com is a good place to start to see if a claim is true or a myth.

In addition to consciously attaching important information to alleged facts, such as whether or not it is true or false, it also helps to put individual claims or facts into a deeper context. For example, it is much easier to remember that the association between vaccines and autism is a myth if one understands its place within the anti-vaccinationist movement. This way people build a knowledge framework where it is much easier to keep individual facts straight. Our memory for individual facts, if they are not connected to such a framework, will tend to drift over time, becoming progressively distorted and even reversed.

In terms of skeptical activism, knowledge of this aspect of human memory can help skeptics frame their message. We do not, for example, want to mention a myth that is not already generally known for the purpose of refuting it. We also need to be conscious of how we state things. Rather than saying that the claim that people use 10% of their brain is a myth, we should say first that people use 100% of their brain – first establish the framework of the positive true statement.

Also we need to emphasize teaching the tools of how to think, rather than just telling people what to think. Along these lines we need to teach people how we know what we know in science, not just the current findings of science. If you teach the process of arriving at a conclusion, that automatically gives them a framework to help remember information correctly and also gives them the ability to reproduce the argument and re-arrive at the correct conclusion – rather than just having to remember it correctly by rote.

This is a method of teaching I use as a medical educator. I try, whenever possible, to get my students and residents to figure out the answers for themselves rather than just give them the answers. And I always try to give them some framework to hang new information on – why does this make sense given what else we know.

This also all fits in well with the scientific approach. All of science is describing one reality, and so it should all fit together and make sense as a whole. There are also more basic intellectual tools – like logic – that apply more generally, even beyond the discipline of science. It therefore makes sense to try to hook everything up as much as possible – to see connections between various parts of science as well as between science and other intellectual disciplines.

Making these connections has the added benefit of aiding our poor human memory, which always needs an anchor. Disconnected factoids will tend to drift off into fantasy land. While well-connected information will tend to stay put.

In this way science, memory, learning, and skepticism all come together – more connections.

7 responses so far

7 Responses to “A Neurological Approach to Skepticism”

  1. mjrobbinson 30 Jun 2008 at 1:14 pm

    That’s a good post, I agree with all of it.

    One related topic is the misuse of sources. You often see papers cited as sources for arguments that, on closer inspection, actually don’t support the argument at all, or are themselves fundamentally flawed – a good if little-known example was the wikipedia entry for a Cuban drug called Policosanol (http://layscience.net/?q=node/73), and an infamous example is of course Wakefield’s discredited paper on the MMR-autism link. This is especially a problem when most papers are still inaccessible to the lay reader, either through the need for subscription, or the arcane language.

    Anyway, the point is that even when our factlets are connected to a source, it still isn’t always straightforward to establish veracity. It’d be nice if some sort of internet site addressed that.

  2. […] invite you to do some more reading. Not being a doctor myself, take a look at a Doctor explaining it. Sphere: Related […]

  3. pecon 30 Jun 2008 at 5:20 pm

    I agree with Novella that we are programmed to be credulous and that skepticism takes constant vigilance. I would go even farther and say that our first impulse is to believe everything we are told.

    This is not because homo sapiens is a stupid species, but because of millions of years of evolutionary adaptation. Our species and its ancestors evolved to live in small emotionally connected groups, where all members shared the same beliefs and values. There were no free thinkers, no skeptics, and the group’s survival depended on harmonious relationships.

    Now things are very different. We have gained freedom and intellectual independence as we have lost emotional connectedness and social harmony. You can’t have it both ways.

    But we still have our powerful inherited instinct for mythology, the glue that holds human social groups together.

    I see people resonating with mythologies everywhere I look. And scientific materialism and progressivism are as dogmatic and mythological as anything in the Western bibles.

    We are social, myth-believing, animals.

    That doesn’t mean I think myths are always bad. They aren’t “true” or “factual,” but they do reflect our social and psychological realities.

  4. DevilsAdvocateon 30 Jun 2008 at 5:59 pm

    One of my two favorite books on memory is Daniel Schacter’s ‘The Seven Sins Of Memory’. Highly recommended. The other is.. uh.. the other is… hmmm.


  5. Roy Nileson 30 Jun 2008 at 6:37 pm

    “Trust but verify.” A universal theme in literature and an operative premise of all survival mechanisms. The Devil is in the verification process, however.

  6. deciuson 01 Jul 2008 at 7:54 am

    For those of you who have missed this comment yesterday.
    It’s probably one of the most hilarious ever.


  7. deciuson 01 Jul 2008 at 9:00 am

    Useless comment, Steven has just blogged about it.

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