Nautilus Rising: A Living Fossil’s Unexpected Renaissance

Underestimation is a rather unfortunate, but powerful, phenomenon. It is easy to become lost in its narrow, dimly lit pathways; much harder to find a way back out. The one hint of beauty that resides in this whole ordeal of underestimation is the potential for a moment, after a seemingly endless battle against a stubborn majority, of brilliant breakthrough. The fight is never finished at this point, but for a short time it is possible to revel in how the world has been stunned into a satisfying hush.

Enter the nautilus.

Nautilius pompilius, the chambered nautilus, is something of a funny creature. With a body almost completely encased by a shell, retractable tentacles emerging only to sense surroundings and food, and with most of its activitImagey occurring in the evening hours, when it ascends from the depths of the ocean to feed in shallower water, the nautilus lives its life quietly and cautiously. While life in the slow lane may not appeal to many, it seems to be working just fine for this secretive cephalopod: having lived for somewhere around 500 million years, it has certainly earned its status as a “living fossil.”

The title “living fossil”, however, doesn’t come without its share of stigma. Because of its relatively primitive brain structure, many people believed that the nautilus was not capable of the same complex learning and memory storage as its more modern relatives, the sleek and shell-less coleoids (squid, octopus, and cuttlefish). Private animal that it is, the nautilus was not about to stage a loud protest arguing for its intellectual capabilities; so for a while the belief stuck that Nautilius pompilius was, for the most part, an uncomplicated creature.

Luckily, the members of the Basil et al. lab (2011) noticed the current that seemed to be pushing everyone’s thoughts in the same direction and did what any good scientists should do: they wondered if the assumptions about the nautilus were wrong. After all, you don’t get to be a “living fossil” without learning a few things along the way. They watched closely, trying to see past the layers of prejudice that had shrouded the nautilus for so long, then used those observations to construct a series of graceful experiments that would allow the creature to reveal its cognitive capabilities. The nautilus did not disappoint.

To test the nautilus’s capacity for learning and memory, Basil et al. (2011) paired flashes of blue light with the release of a fish head odor, a favorite nautilus snack, to see if the animals would learn and remember the association between the light and the food. Nautiluses extend their tentacles when they sense the promise of a delicious meal, so the researchers used this response to measure whether the creatures were learning. The experiment had two conditions: in the first, the flashes of light were always immediately followed by the release of the fish head odor, creating a temporal link between the stimuli; in the second, the fish head odor was released at regular intervals, but the flashes of light were completely random. Both conditions involved a series of training trials, after which the blue light was shown on its own, without any odor. Only in the first condition, where the odor always followed the light, did the nautiluses extend their tentacles in response to the light alone – they had learned that the flashes of light predicted the potential for food, so their tentacles did a happy dining dance whenever they saw it.

Not only can nautiluses learn an association between light and food, but they can also retain that newly acquired information (Crook & Basil, 2008). Their short-term memory is excellent – even after an hour of only seeing the flashing light, the nautiluses kept extending their tentacles with vigor, ever hopeful for a meal. This excited response died down between hours one and six, which the researchers attributed to a period of memory consolidation, but shot back up again around the twelfth hour of seeing the flashing light, demonstrating a previously unheard of capacity for long-term memory. Despite having no specific brain regions dedicated to memory storage, the nautilus seemed to be just as capable of learning and remembering novel information as its coleoid counterparts.

Those same tentacles that wiggle with joy at the prospect of food also allow the nautilus to maintain a keen awareness of its physical surroundings. Tentacles help nautiluses to feel their way along coral reefs during their nocturnal journeys for meals, as they search for paths that include both hiding spots from predators and undiscovered food stores. Because this heightened sense of touch would be crucial for moving about in the darkeImagest parts of the ocean, Crook et al. (2009) predicted that the nautilus would be particularly astute at detecting changes in the structure of coral reefs.

Sure enough, the nautiluses showed an incredible ability to sense variations in their environment. After being allowed to explore a tank housing an artificial coral reef for a few hours, the nautiluses were removed from the tank and the cinder blocks that made up the synthetic reef were rearranged. When the nautiluses were brought back and allowed to explore the reef once more, they suddenly became extra vigilant, distancing themselves from the side of the reef and only swimming close to it after some time had gone by. This finding speaks not only to the nautilus’s learning and memory capacity, but also hints at a survival strategy of cautious investigation, as opposed to fearless exploration, that may have helped to keep to keep the species alive for all these years.

Against all odds, the nautilus has managed to move beyond the stigma of being a “simple” creature – and these findings are likely just the beginning of many more to come. Unfortunately for the nautilus, the majority of the research so far on the cognitive complexity of cephalopods has focused on coleoids, meaning nautilus research has a bit of catching up to do. But Basil et al. have taken a crucial first step in illuminating the creature’s hidden abilities, as well as providing multiple directions for future studies. They have shown that our tendency to underestimate will no longer do – it’s time to allow the nautilus to lead where it will, quietly astounding us along the way.

 

References:

Basil, J., Barord, G., Crook, R., Derman, R., Hui Ju, C., Travis, L. & Vargas, T. (2011). “A synthetic approach to the study of learning and memory in Chambered Nautilus L. (Cephalopoda, Nautiloidea).” Vie Et Milieu – Life and Environment, 61, 231-242.

Crook, R. & Basil, J. (2008). “A biphasic memory curve in the chambered nautilus, Nautilus pompilius L. (Cephalopoda: Nautiloidea).”Journal of Experimental Biology, 211, 1992-1998.

Crook, R., Hanlon, R. & Basil, J. (2009). Memory of visual and topographical features suggests spatial learning in nautilus (Nautilus pompilius L.).” Journal of Comparative Psychology, 123, 264-274.

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On Stirring Numbers and Waltzing Galaxies: How Movement Can Help Us Learn about Abstract Concepts

For me, reading has always been something of an improvised dance. Or rather, an improvised dance in which I have complete control over the tempo, rests, and repeats in the score. Words like notes weave the intricate melodies and harmonies of sentences and paragraphs. Central arguments become grand crimages-20escendos, culminating in climactic chords. Particularly poignant or complex phrases implore me to linger, listen closely, unpack the manifold layers. And for the entirety of this orchestration, my hands never stop moving to the cadences and lilts of the prose.

These eccentric reading habits have earned their fair share of wary sidelong glances; after all, there probably aren’t many people you know who gesticulate wildly as they peruse the pages of a Campbell textbook on introductory biology. But given the chance, who wouldn’t wish to find some way to animate the oft-dry words of scientific text? Why just read about the cell and its bustling inner world when you can conjure up its invisible sphere right before your eyes – a nucleus here, some mitochondria there, and would you look at the cisternae on that Golgi body! With a few flicks of the wrist, the cell suddenly becomes beautifully vibrant, teeming with activity and bursting with life.

While it should come as no surprise that cells are quite the lively bunch, it can be easy to forget their dynamic nature while staring at a textbook page full of static print. Peers would often ask how I could memorize so many inane scientific concepts; until recently, I never really had a great answer. Science never seemed all that dull to me, but obviously this was not the majority opinion. Then it hit me, as a hand that so wildly gesticulates about glia and galaxies is want to do: perhaps it was the movement that helped me remember. After all, whenever I was explaining the most recent scientific idea I had fallen madly in love with – to a friend, to my dog, on an exam – I would call upon the same dances I had created to explain the ideas to myself in the first place.

“That’s all well and good for science”, you may be thinking at this point, “but what about something as abstract as an algorithm? How can a movement bring a math problem to life?” Since the title of this post promised numbers, you shall not leave empty-handed. The question of whether motion can help people learn math is the very thing that researchersImage Cook, Mitchell, and Goldin-Meadow sought to answer in their 2008 study with the pithy yet fitting title: “Gesturing Makes Learning Last.” It’s probably already fairly evident, but just in case you missed it, their results pointed to a pretty promising finding that movement and math go hand in hand with good learning.

For their experiment, the researchers wrangled together a group of 84 third and fourth grade students to teach them math (the nerve of these scientists!) The kids were placed in one of three groups: the speech group, the gesture group, or the combo gesture and speech group. Now here’s the fun part. All three groups were taught the same set of math problems that were some variation on the theme of  “4 + 9 + 3 = 4 + ___, now fill in the blank”, a concept which none of them had learned prior to the experiment. The differences lay in what group they had been randomly assigned to. For the speech group, the children were told to repeat the phrase “I want to make one side equal to the other side”; for the gesture group, the children were asked to make a motion of sweeping one hand under the left side of the equation, then under the right side; and for the speech and gesture group, they got to do both. Lather, rinse, repeat a few more times, then they were released to solve a few problems on their own, still reciting the phrase or performing the gesture they had learned before. Thus ended phase one of the study.

Four weeks later, on a normal school day, the teachers of the 84 study participants gave them a handout: math problems just like the ones they had solved in the experiment. No mention was made of the study, nor did the children have to recite a phrase or make a gesture – they simply completed the test and handed it back in in. But while the tests they were given were all the same, the scores turned out to be quite different. The kids in the groups who got to do a little math dance solved significantly more problems correctly than the children who had only moved their mouths. A choreographed concept, it seemed, was better for memory than a math-filled monologue.

A simple study and a beautiful finding, but why should it be true that motion, math, and memory make such a lovely trio? One possibility is that motion makes your working memory load a little less. When you’re first learning a concept, your brain is working Imageovertime to pack in a lot of novel information; add movement to the mix, and you’re representing the new knowledge in two places now – in your body as well as in your mind. By waving your hands around a bit, you’re putting less drain on your brain to hold onto a lot of information all at once, and you suddenly have a little more cognitive energy freed up to focus on making the memories last.

Another explanation is that movement helps you remember tough ideas by externalizing the abstract, substantiating things that seem frustratingly intangible. By waving a hand underneath an equation, a tricky mathematical concept is suddenly made concrete, motioned into your present reality. The problem is now one that lives in the world rather than solely in the mind, and it’s become a little bit easier to grasp with the hands that helped it dance into existence.

So if the results of the study show such promise and motion really does help students learn math, should we all start doing the Academic Macarena and make a move towards movement in the classroom? Short answer: it probably wouldn’t hurt. Even if it turns out that pairing motion with equations like the ones in the study is the only combination that works to increase memory through movement, and even if it isn’t the only answer for better learning in school, adding a bit of motion to an otherwise inert day would certainly be a welcome change. Not to mention, how fantastic is the image of a shimmying class of calculus students?

Just picture this: strolling through the quiet halls of an elementary school, you hear the distant voice of a teacher talking about the structure of DNA. You come nearer to the classroom, expecting to see students furiously scribbling in their notebooks the elucidations of base pairs, sugar-phosphate backbones, and hydrogen bonds. As you peer through the window, though, you curiously find that not a soul is seated. Instead, your eyes are greeted with a sea of hands waving and weaving double helices, pairs of hands pairing base pairs in the air, tracing the lines of hydrogen bonds between them. It might sound a little strange at Imagefirst, but when you think about it, it kind of makes sense. After all, DNA is a motion-filled macromolecule, always replicating and dictating, unwinding and transcribing. Why shouldn’t the way we learn about it be just as gorgeously dynamic?

 

References:

Cook, S. W., Mitchell, Z. & Goldin-Meadow, S. (2008). Gesturing makes learning last. Cognition, 106, 1047-1058.

Don’t Blink: The Science of the Mona Lisa’s Flickering Smile

Gazing into the eyes of Lisa Gherardini, the famous sitter of Leonardo da Vinci’s Mona Lisa, viewers are often struck with two distinct reactions: one of complete wonder, and one of absolute frustration. It doesn’t take much time to suss out what is causing the latter reaction – the legendary “flickering smile” is enough to make even the most composed Imageamong us want to tear out a couple of hairs while contemplating the eternal (and eternally unanswerable) question of what her enigmatic expression could possibly mean. Is this a smile of joy, of secrecy, of seduction? And perhaps the most unnerving question of all – should her expression even be considered a smile in the first place?

While I cannot hope to provide any satisfactory answers to this larger philosophical query as to the motions of Ms. Gherardini’s mind (really now, what were you expecting from this blog post?), I can ease some of the vexation surrounding this portrait by offering an explanation of a different sort. Even if it is nigh impossible to pin down the thoughts of this mysterious woman, it is entirely possible to figure out why her expression is so difficult to read. The answer, inevitably, lies in Leonardo’s genius as both a painter and a thinker.

The first order of business calls for a good definition of the word sfumato. While the literal translation to English is simply “smoke”, in this context the word actually refers to a painting technique used by Leonardo in which pigments are blended together to create smooth transitions between tones to avoid the use of harsh outlines. In the Mona Lisa, Leonardo’s use of sfumato is most evident around the corners of Lisa’s eyes and mouth. ImageThe result is a more natural rendering of how the human face appears to the naked eye; after all, none of us actually has bold black lines separating our eyes and mouths from the rest of our faces (unless you happen to wear a lot of eyeliner, in which case I offer my sincerest apologies).

Sfumato lends itself not only to creating a more natural representation of color, but also of motion. The technique is what causes us to perceive constant, subtle movements in the expression of Lisa Gherardini – the same movements that you would find in a real human face. So why does the act of blending pigments cause us to perceive something as complex as a flickering smile on the flat surface of a canvas? Diogo Queiros-Conde helps us to unpack the reasoning behind this by applying his theory of entropic skins geometry (or ESG) to the Mona Lisa, demonstrating how the more complex the sfumato is in a painting, the more likely we are to perceive motion.

As Queiros-Conde explains it, it is actually the act of blinking that sets the Mona Lisa into motion. Here’s why: when your eye blinks, it filters less and less light to your retina; with less light going to your retina, your eye sees fewer colors. Blinking involves a continuous series of steps in which your eye filters in less light to the retina, ranging from when your eye is open (full light) to when your eye is closed (no light). At each step of the blinking process, you are seeing a slightly different combination of colors based on how much light is being filtered into your eye. The more variation there is in color when you are viewing an image in full light, the greater the number of images you see as you blink.

Yet this by itself does not explain why people perceive motion in the Mona Lisa. Thinking back to the painting technique of sfumato, you will recall that it involves the blending of an array of different pigments, and that Leonardo primarily used it around the corners of the eyes and the mouth of Lisa Gherardini. The more pigments Leonardo uses for the sfumato, the more colors we see as we look at the painting in full light. Why is her expression so hard to pin down? Because the very act of blinking as you view the painting means you are seeing hundreds of variations of the same image. Every step of light filtration generates a new combination of colors that reaches your eye, but with each blink taking less than half a second to occur, you hardly have time to process what is happening. For just a moment you think you have managed to settle the mystery of her expression, to still the flickering of her smile. Yet at the blink of an eye, it’s already danced away.

But think twice before you engage in an intense staring contest with this famous woman: even if you aren’t blinking as you look at the painting, Leonardo has cleverly erased (using sfumato!) any traces of wrinkles around Lisa’s eyes and mouth that might provide a clue as to her internal state. It is no coincidence that these are the exact locations we look to when we are trying to figure out what emotion someone is feeling. No matter how you look at the Mona Lisa, she will always be able to evade concrete interpretation. At least now you know why her smile flickers, and how to hold it still for just a moment – that is, until your next blink.

References:

Queiros-Conde, Diogo. “The Turbulent Structure of ‘Sfumato’ within ‘Mona Lisa.’” Leonardo 37 (2004): 223-228.

Link

 

imgres-6“Here is Today” is a wonderful and deceptively simple graphic illustrating this day in time as it relates to the age of the earth, the arrival of insects, and a number of other points of interest along the evolutionary path of the universe. One can only hope that as we are constantly moving towards the use of more technology in classrooms, this is the sort of thing that will emerge as a way to highlight key concepts in science classes. In the meantime, though, have fun clicking your way through time and perhaps learning something new along the way (who knew that the current epoch was named “Holocene?”)

Planting my first post

In which I awkwardly impart the following information:

1. Hi. This is my blog. Welcome! Please, make yourself comfortable. Grab a chair. Fix a drink. Put on some light jazz (if that’s what you’re into). Pet a llama (if that is also what you’re into)*. This is as much your space as it is mine. But this is also not MySpace, so let’s not get confused.

2. This particular blog is going to be about science (don’t stop reading).

3. Yes, I know. Really I do. I know you might be feeling just a bit apprehensive. In fact, you might be feeling a lot apprehensive. After all, it’s SCIENCE (cue “Jaws” theme, or anything else that inspires an equally and inappropriately horrified reaction in you). It’s the thing that sends my friends majoring in the humanities (and, strangely, some fellow psychology majors) running with ears covered, eyes closed, all senses blocked lest a stray molecule of scientific thought creeps in through some secret crevice to confuse them to the point of weeping hysteria.

But I’m not here to send you into a fit of weeping hysteria.

I’m here in pursuit of the “aha!” moment.

I’m here because, in 99% of the cases in which I’m trying to explain a scientific concept to someone, they end up getting it. Not only that, but they’re also really proud of the fact that they get it. And when that happens, they want to explain it to anyone who will listen. Why, you might be curious to know? Spoiler alert: it’s because science is AWESOME.

I love it when people come to realize that science doesn’t have to be difficult. It can be wacky, inspiring, funny, beautiful, terrifying, breathtaking, bold, and sometimes downright strange. And of course, it can be incredibly complex. But here’s some food for thought: you’re incredibly complex, too. That funny object sitting between your ears? It’s what’s allowing you to see all of these symbols and make sense of them as letters, words, sentences, and then finally concepts, thoughts, and ideas – all without you having to put much effort into it. And that’s only the beginning of what your mind is capable of. How’s that for complexity?

So, if you’re game (and I hope you are), let’s set out together in search of the “aha!” moment. Bit by bit, post by post, I’m hoping to make science seem just a little less daunting. And if you already love science? Keep up the excellent work. Go forth and inspire others to love it, too. Fact-check my posts. Perhaps you’ll find some interesting pieces of information here, as well!

I’m just starting out with this science writing thing, so any and all feedback is quite welcome. If you find something confusing or think I may be misinformed on a topic, let me know and I can have some “aha!” moments about my own writing and storytelling. Likewise, if you really enjoy something on here, please tell me! I’d love to know what excites and inspires you, too.

Oh, and the 1% of people who don’t know what I’m talking about when I’m trying to explain some scientific concept? It’s because I wasn’t explaining it well in the first place.

That’s all for today. But check back soon because I’ll be sure to be procrastinating for final exams post more later this week!

Cheers to new ideas,

Alex

*Side note: if you are the owner of a llama, I’d very much like to meet you.