Monday Musings: Dirt Deficit Depression, Active Learning, and Thought for Food

Things are nice and clean nowadays. You can easily go a day without seeing a single speck of visible dirt, while hand sanitizer stations dotting the modern landscape take care of the less visible stuff. This is, of course, an environmental novelty with big implications. We”re all familiar with how the extreme sterility of modern environments negatively impacts the ability of our immune systems to do their jobs. We get more exaggerated and sustained inflammatory responses to things that don’t really merit them. We get a lot more asthma and allergies, especially as kids. Well, a recent review in the Archives of General Psychiatry suggests it goes even further – all the way to clinical depression. To be more precise, dysfunctional inflammatory responses of imbalanced immune systems due to sterile environments are causing depression in kids. A lack of exposure to “old friends,” or the microorganisms normally present in dirt, food, and the gut, increase levels of depressogenic cytokines, so the natural inflammatory response to psychosocial stressors is “inappropriately aggressive.”

So, like I’ve said a bunch of times already, don’t fear the dirt. Exercise caution, however, when using this study as justification for shirking household chores.

Take Control of Learning to Make it Count

We learn best by doing. This is sheer common sense, handed down over hundreds of thousands of years of tool-making, structure-building, trap-setting, and wildlife-cataloguing. These days, you learn to change a tire not by consulting the manual, but by crouching down beside the car as your dad does the actual thing and participating. You get better at shooting baskets by shooting baskets. This is said to be the best way to learn because it combines physical participation and mental engagement in the task. A new study explains why this might be the case.

Researchers asked participants to memorize the exact positions of objects arranged in a grid on a computer screen. The “active” group was given control over a viewing window that revealed the objects’ locations in the grid one square at a time. They used a mouse to move the window. The “passive” group viewed a replay of the window movements from the previous group. Both were asked to recall the positioning of the objects in the grid. The active group was better able to remember the objects used and their locations, even though both groups witnessed the same objects in the same places being revealed in the same order. In the active group, brain activity was greatly enhanced, especially in the hippocampus. Increased hippocampus activity seemed to be the key; later experiments showed that amnesia patients with damaged hippocampuses saw no learning benefit from actively controlling the viewing window.

This phenomenon might explain why some people seem to retain knowledge better when they take notes in class with a pen and paper, rather than simply typing on a keyboard. Keyboards allow you to be more distant from the writing of the material, whereas with a pen you’re physically forming the individual letters and words. The key, of course, is engaging both mentally and physically in the act of learning. You need to take an active role – don’t just jot stuff down mindlessly, or watch as someone else changes the tire. Get in there and get your hands dirty. Own what you do as you’re learning it, and it should stick.

Thought for Food

We know that human imagination is a powerful force, but did you know that thinking of eating a particular food can sate your appetite for that food? Scientists at Carnegie Mellon University asked participants in a recent study to vividly imagine eating either three M&Ms or thirty M&Ms, individually, one at a time (they were also asked to imagine another repetitive task, pumping either thirty or three quarters into a laundry machine, respectively, to ensure that the effect was not just due to imagining any repetitive action). So, instead of imagining they were eating a bag of candy as a single unit, they were told to imagine thirty individual instances of eating a single M&M. The more candy they had imagined eating, the less they ate when given free access to an entire bowl of real M&Ms. Simply by visualization, habituation – the lessening of an organism’s psychological or behavioral response to a stimulus upon repeated exposure to the stimulus – had occurred. This might come in handy when cravings hit; instead of hiding from your cravings, vividly imagine every single bite of every last morsel of whatever food you’re trying not to eat!

Do the great outdoors raise your spirits (like they do mine) – and are you happier when you mix it up off trail and get a little dirty? How do you learn best? If you give it a shot, let me know if appetite suppression through food visualization actually makes a palpable difference. And, as always, shoot me a line to any interesting stories you want me to cover!

TAGS:  mental health

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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34 thoughts on “Monday Musings: Dirt Deficit Depression, Active Learning, and Thought for Food”

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  1. I love your Monday Musings. I completely agree about the dirt and never like to walk away from a trail run without being quite muddy.

  2. Doesn’t the visualization thing directly contradict the “don’t focus on the marshmallow” advice from that link the other day?

  3. I never make the powerpoint slides for my lectures available until after I’ve finished lecturing on the material. This forces students to take notes based on what they see on the slide and what they hear me talking about in lecture, rather than being duped into feeling that they already know the material well enough by seeing the printed lecture slides in their hands. Judgments of learning (JOL) at the time of lecture are extremely misleading indicators of memory performance on a future test. What the Bjorks call “desirable difficulties” in learning.

  4. I’ve definitely used food visualization to curb cravings before. Especially with very sugary foods like glazed donuts or cupcakes. I imagine the gooey texture as I take a bite, and the way the sugar rolls on my tongue. I might even make a chewing motion with my mouth to complete the effect. At the very least, it serves as a distraction from the craving until I can occupy my mind with something else.

  5. Hmmm. Somehow I don’t think visualizing drinking a cold gin and tonic will make me crave it less rather than more, but I’ll give it a try.

  6. it has been a while that i did not have a day without checking your web site…better than coffee :)) thnks Mark and your team

  7. Mm, I wonder though … if the body responds with an insulin spike to diet and sugar-free products when there is no sugar to be mitigated might it likewise respond to detailed imaginings of eating sugary foods. I wonder.

    1. I guess I already read somewhere that the body actually pre-releases a certain amount of insulin in order to prepare the environment for the arrival of carbs. It’s probably within the phase of salivation which preceds eating of sweets – at least I still have vivid memories of how I was a slave to candies.

      So maybe imagining may be a bit harmful in this case, but still better than actually digesting the poison.

  8. When I go grocery shopping, I sometimes walk down the candy isle (or ice cream isle) and find my favorite thing. I stare at it and imagine how wonderful it tastes and smells.
    Then I walk away, leaving it on the shelf. This usually satisfies my cravings.

  9. instead of visualizing the candy or sweets, I visualize how good it is going to feel to be at my goal weight. That is a powerful motivator for me.

  10. “Now for the first time in the history of our species, our bodies are being deprived of exposure to everyday germs because we live in such a sanitary environment. Think about the immune system as one that needs info from the environment to guide its development and function; if you live in a rich microbial environment, you get exposed to germs that help your immune system develop.”

    — Thomas McDade

  11. Re thinking about food, I like to pull up the online menus of high end restaurants, and decide what I would order … conjure up a meal of several courses, including dessert.

    I find that doing this makes me miss eating out a lot less.

  12. On the matter of visual / hands-on learning, yes all that.

    Also I think new exciting tools are crucial to engage and push students as far as how they cognitively interact with concepts/texts/works.

    For instance, a guy named Bradford Paley has been working on a tool that visually maps out a literary text based on frequency and locations of key words in the text:

    (see what they’ve done with Hamlet and Alice in Wonderland)

    There are similar sorts of tools being R&D’ed for other applications, including new ways to “read” film. By the way, film analysis seems to be one of the most under-appreciated studies right now, since it shines light on the fact that as a society we’ve developed a new comprehensive set of visual semantics and vocabulary. It has irreversibly changed how we understand the world at large though we hardly reflect on it.

    If we are immersed in entirely new medias, in contextual ways we are not fully self aware, we need appropriate methods of modeling and annotating huge amounts of seemingly unstructured information. I do think new visual vocabulary will continue to develop and be formalized as an adaptive mechanism for this era.

    I agree about the Powerpoint problem. It’s a seriously broken tool, giving a false illusion that grasping sequentually displayed meanings implies grasping rich underlying references to concepts. It’s been a step in the opposite direction.

  13. The idea of active learning is spelled out very well in John Medina’s “Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School.”

    Medina even discusses our Paleo ancestors and their active lifestyles being the models for learning. he says the best business meetings would have everyone walking about 2 mph.

    He further discusses the idea that Paleo-man’s environment called for quick responses and adaptations that led to creativity, intelligence, and resistance to stress. Studies show the same is true of modern man–change things up and he learns faster and becomes more creative while adapting to change more easily.

  14. My mom used to have a trivet in her kitchen that read “My kitchen–clean enough to be healthy and dirty enough to be happy.”

    Wise words to live by.

  15. Every time I see one of those studies about the wonders of dirt (so to speak), I feel lucky. My daughter has no deficit there. We’re beginning homesteaders and she get plenty of dirt….

  16. I’m not to sure that visualizing a cupcake would sate my appetite for one. The thing is that since I have eliminated all that junk, my palate has awakened to the wonderful variety of extremely flavorful and satisfying healthy foods there are. I don’t think about ice cream or cupcakes in the same way anymore. Thinking about them while writing this leaves me less with a feeling of desire, and more with a feeling of aversion. One desire that is left in this regard is that so many of my friends and acquaintances are a little annoyed that I don’t eat like I used to. I’m looking for more like minded people to get to know. Find me on Facebook. Dr. David A. Flynn.

  17. I had a professor who would not hand out lecture powerpoints before or after the lecture. He would put up the slide, give you time to copy the notes and then talk around it.
    I was studying with a girlfriend who had got copies of the notes from an old student of his so she didn’t write anything down because she ‘already had it.’
    Guess who walked away with a High Distinction in that class verses a simple pass?
    Up until that point our grades had been much the same. We had that same professor for 3 semesters and she never ‘got’ it. Needless to say our averages were a bit different by the time we were done :p

  18. Interesting. I just realized whenever I bite my nails obsessively, it’s when I’m going through a rough spot.

    Maybe my body is trying to take in some more dirt. If so, I have a smart body! Now if only it could get me a job…

  19. Great posting. Reminds me, I would love to see a posting on how to competently order from the butcher for a side of beef or hog, lamb, etc. I recently had one of each of these butchered for me, was not sure about what to ask for, and wasn’t happy about the results.

  20. The study on thinking of food for appetite control was interesting. I’ve always figured thinking of food would just stimulate appetite, but maybe actively thinking of eating each little piece helped out.

    1. I agree; my gut reaction is that if I think about a food I will want it more. However, this is almost a mindfullness exercise: think about EACH LITTLE PIECE.

      I am excited to try it.

  21. Mark’s ahead of the game as always! There is an article about the Carnegie Mellon study in the “Science Times” portion of the New York Times today!

  22. The lack of good bacteria begins at birth!

    I’m a birth assistant in one of DC’s only freestanding birth centers. Here, we inform our clients that washing a newborn will not only compromise their ability to thermo-regulate (make them cold), but it will also wash off all the good bacteria that is colonizing their newly formed gut. One of our trusted pediatricians tells our clients NOT to wash their newborn for at least two days after birth, and to hold them skin to skin whenever possible. That skin to skin contact also aids the colonization of their gut with bacteria and germs from mom and dad that will boost their immune system.

    This is in contrast to a recent hospital birth I attended where the newborn was washed within hours of birth. (which they will tell you that they need to do lest they send someone out of a hospital with bodily fluids on them – a public health concern…*one more reason to birth out of hospital)

    Thanks for posting, Mark. 🙂

  23. Actually, I had a look at that study about imagining eating M&Ms, and I thought it was bunkum. The difference between the groups was 2 M&Ms- which is a big difference when the group that ate more had 5 M&Ms! More research is needed.

    I really want to hear more about gut bacteria. Could we have a post on what these “old friends” are and how we could incorporate them? Also, are they in probiotics, or in bacteria we may be commonly exposed to in our houses, like mildew and mold? I have a suspicion that our guts are far more influential in our wellbeing than we know; I for one was shocked to learn that there are actually neurons in our gut, exactly like the ones in our brains. I learned that in Human Physiology, and it was essentially brushed over with “But we’re still learning about this, check this space for further information.” My professor did say, however, that it’s possible that gastric bypasses and lap bands work not by restricting food intake but rather by changing the reactions of the gut- in essence, that they work but probably not for the reason we think they do. Our bodies are so fascinating!

  24. Today, I went to the beach front with my children.
    I found a sea shell and gave it to my 4 year old daughter and said “You can hear the ocean if you put this to your ear.” She placed the shell to her ear and
    screamed. There was a hermit crab inside and it pinched her ear.

    She never wants to go back! LoL I know this is entirely off topic but I
    had to tell someone!

  25. I got a healthy dose of dirt today, or rather, mud!! I went for a walk and of course I wanted to go in the trail area instead of the sucky pavement. I was sort of going fast and I totally slipped in some mud! I was so thankful for having landed in a perfect break-fall (thanks, karate). I really didn’t get ‘that’ dirty, just my feet, and hands were muddiest with a bit on my side hip/thigh. If I didn’t break-fall the way I did I would have been completely covered head to toe and maybe all over my face too. lol