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Colonoscopies Clarify Inner Workings of Minds

The views expressed are those of the author and are not necessarily those of Scientific American.

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Memories are story shaped. As are understandings. To remember, or make sense of, a thing is to have a story about it. Colonoscopies and correcting cathartic errors can probe the inner workings of these stored stories.

Memories aren’t machine-like recordings. They resemble movies more than raw footage. They are carefully lit and edited. Daniel Kahneman says of this filtering and forming, that “Confusing experience with the memory of it is a compelling cognitive illusion.”

Kahneman used colonoscopies to illuminate the ends of human memory. Comparing how conscious colonoscopy patients rated their experience of pain every 60 seconds during the procedure with how they recalled the total amount of pain, resulted in “two principles of memory.” First “duration neglect” whereby the time the procedure took had no effect on recalled pain. Second the “peak end rule,” recalled ratings depended only on the peak of pain and it’s level at the end of the procedure.

So memories, and decisions based on them, are often “not correctly attuned to experience.”

Our experiencing self often has adaptive amnesia. The raw footage of most experience isn’t important, but we evolved to find emotionally significant events worthy of stories and storage. “The same core features appear in the rules of narratives and in the memories of colonoscopies, vacations, and films.” It makes sense that “Duration neglect is normal in a story, and the ending often crucial.”

Stories can change our health, physically and mentally. Jamie Pennebaker’s research shows certain kinds of disclosure can reduce the health-damaging effects of past trauma. He asked subjects to write about their “most upsetting or traumatic experience,” for just 15 minutes on four consecutive days, then tracked their health for a year. Those whose stories showed increasing understanding over the four days had significantly fewer illnesses than those who simply repeated the story they started with. The key wasn’t expressing themselves, or venting emotions, but rather making new sense of their situations, changing their explanatory story. Though popularly believed, Jonathan Haidt says there is no evidence for catharsis having therapeutic effects. Catharsis rehearses and trains the prior state. Whereas therapy should cause a change. Alter the old story.

Many would find disturbing the combination of: Steven Pinker’s “to a very great extent our memories are ourselves,” Kahneman’s “I am my remembering self and the experiencing self who does my living is like a stranger to me,” and Oliver Sacks’s observation that we have “no mechanism in the mind or the brain for ensuring the truth…of our recollections.”. Many fear that stories mislead.

But stories are how our memories and understanding works. By all means get better stories. But don’t tell yourself the tall tale that you can do without them.

Illustration by Julia Suits, The New Yorker Cartoonist & author of The Extraordinary Catalog of Peculiar Inventions.

Previously in this series:

Kahneman and Bentham’s Bucket of Happiness
Kahneman’s Clarity: Using Mysterious Coinage in Science
What Rational Really Means
The Cognitive Science of Star Trek

Jag Bhalla About the Author: Jag Bhalla is an entrepreneur and writer. His current project is Errors We Live By, a series of short exoteric essays exposing errors in the big ideas running our lives, details at His last book was I'm Not Hanging Noodles On Your Ears, a surreptitious science gift book from National Geographic Books, details at It explains his twitter handle @hangingnoodles Follow on Twitter @hangingnoodles.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. SparksMD 6:29 pm 05/31/2013

    One of the most interesting characteristics of physical pain is its ‘relative’ nature. In other words, once the pain subsides, it’s entirely forgotten unless chronic in nature. This rarely applies to traumatic or psychological suffering; hence the PTSD phenomenon.

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  2. 2. BrainBites 10:10 pm 05/31/2013

    The only problem is – the amount of pain is very operator dependent and based on personal expectations. I had my first colonoscopy last week, unanesthetized, and experienced no pain and only mild discomfort. Males tend to have larger colons and can tolerate cscopy well. Plus I had researched the procedure and knew what sort of discomfort to expect (mainly very mild gas pressure as the colon was inflated). I watched the whole thing and it was fascinating. So a study (if this is indeed a study – hard to tell from the book excerpts)like this would select for (I assume) only those who experienced pain during the procedure and were unanesthetized, and I have to wonder whether the trait being examined is related more to anxiety rather than actual pain. Bottom line (no pun intended), I’d need to see the original study before I concluded anything. The main reason I’m commenting is that I want to reassure people that they don’t need to be afraid of a colonoscopy, which all the talk of “pain” would imply – it’s no big deal.

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  3. 3. ultimobo 6:57 pm 06/7/2013

    from my understanding of neural pathways – recall is associated with feeling – while boring experiences can be quickly forgotten – traumatic experiences can instantly etch a permanent neural pathway which will remain hypersensitive for many years (adrenalin/cortisol? other experts can advise)

    last night watched a woman in her 50s on TV, her eyes gushing with tears as she recalled being sexually groped for only a few seconds as a 14yo by a older famous man – if that was her regular experience she may have forgotten it, but it appears it was so traumatic (with rethinking/reinforcement – blaming herself for cajoling her mother to let her go on this trip and then not telling anyone about it afterwards as it would spoil their trip) that 40 years later her lips quivered with emotion as she recalled the experience.

    I will guess she has replayed that experience over and over in her head so many times that it’s almost continual loop autoplay – she said she can’t sleep at night without leaving the TV on to block her thoughts.

    As someone who did meditation to clear my mind I see many people’s rat-cage hamster-wheel thoughts like celluloid film projection, each thought pulling the next automatic assocation into the screen of the mind. Meditation – to clear the mind – allows my empty mind to perceive with perfect clarity the beauty of the world around without being my judgement being clouded by busy-thoughts like ‘I must – I should – that’s bad – that’s good – I want – I like – can I get – how can I get – why can’t I – I’m not happy’

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  4. 4. popseal 7:21 pm 07/5/2013

    Since so many people have their heads somewhere way up their own arse, a colonoscopy may involve brain waves. In that vain, Doctors discovered that an optic nerve was crossed with a nerve in my colon and that explained my &hitty outlook on life.

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