Brain Pickings

Posts Tagged ‘science’

14 APRIL, 2014

The World’s Oldest Living Things: A Decade-Long Photographic Masterpiece at the Intersection of Art, Science, and Philosophy

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What a 13,000-year-old eucalyptus tree reveals about the meaning of human life.

“Our overblown intellectual faculties seem to be telling us both that we are eternal and that we are not,” philosopher Stephen Cave observed in his poignant meditation on our mortality paradox And yet we continue to long for the secrets of that ever-elusive eternity.

For nearly a decade, Brooklyn-based artist, photographer, and Guggenheim Fellow Rachel Sussman has been traveling the globe to discover and document its oldest organisms — living things over 2,000 years of age. Her breathtaking photographs and illuminating essays are now collected in The Oldest Living Things in the World (public library) — beautiful and powerful work at the intersection of fine art, science, and philosophy, spanning seven continents and exploring issues of deep time, permanence and impermanence, and the interconnectedness of life.

Llareta

3,000 years | Atacama Desert, Chile

Baby llareta

With an artist’s gift for “aesthetic force” and a scientist’s rigorous respect for truth, Sussman straddles a multitude of worlds as she travels across space and time to unearth Earth’s greatest stories of resilience, stories of tragedy and triumph, past and future, but above all stories that humble our human lives, which seem like the blink of a cosmic eye against the timescales of these ancient organisms — organisms that have unflinchingly witnessed all of our own tragedies and triumphs, our wars and our revolutions, our holocausts and our renaissances, and have remained anchored to existence more firmly than we can ever hope to be. And yet a great many of these species are on the verge of extinction, in no small part due to human activity, raising the question of how our seemingly ephemeral presence in the ecosystem can have such deep and long-term impact on organisms far older and far more naturally resilient than us.

Pando (quick aspen)

80,000 years | Fish Lake, Utah, USA

Alerce (Patagonian cypress)

2,200 years | Patagonia, Chile

Above all, however, the project raises questions that aren’t so much scientific or artistic as profoundly human: What is the meaning of human life if it comes and goes before a patch of moss has reached the end of infancy? How do our petty daily stresses measure up against a struggle for survival stretching back millennia? Who would we be if we relinquished our arrogant conviction that we are Earth’s biological crown jewel?

Sussman offers no answers but invites us, instead, to contemplate, consider, and explore on our own — not as creatures hopelessly different from and dwarfed by the organisms she profiles, but as fellow beings in an intricately entwined mesh of life. What emerges is a beautiful breakage of our illusion of separateness and a deep appreciation for the binds that pull us and these remarkable organisms in an eternal dance — our only real gateway to immortality.

Dead Huon pine

10,500 years | Mount Read, Tasmania; Royal Tasmanian Botanical Garden, Hobart

Indeed, it is this capacity for questioning that makes Sussman’s perspective particularly powerful. She herself, adding to history’s most beautiful definitions of art, considers it the supreme responsibility of the artist:

The role as an artist [is] to answer some questions, but to ask many more.

Bristlecone pine

5,068 years | White Mountains, California, US

Bristlecone pine detail

5,068 years | White Mountains, California, US

Sussman writes in the preface:

What does it mean when the organic goes head-to-head with the geologic? We start talking about deep time and the quotidian in the same breath, along with all the strata in between. All of these organisms are living palimpsests: they contain myriad layers of their own histories within themselves, along with records of natural and human events; new chapters written over the old, year after year, millennium after millennium. When we look at them in the frame of deep time, a bigger picture emerges, and we start to see how all of the individuals have stories, and that all of those stories are in turn interconnected — and in turn, inextricably connected to us all.

[…]

The oldest living things in the world are a record and celebration of the past, a call to action in the present, and a barometer of our future.

Brain coral

2,000 years | Speyside, Tobago

Baobab

2,000 years | Limpopo, South Africa

Welwitschia Mirabilis

2,000 years| Namib-Naukluft Desert, Namibia

To be sure, the project has resonance far deeper and wider than a purely artistic pursuit. In a culture where 40% of people don’t believe the world is more than 6,000 years old — a kind of faith-washing known as Young Earth Creationism — Sussman’s work brings to light tangible, irrefutable, gloriously alive evidence of the scientific reality. After all, when beholding a majestic 13,000-year-old Eucalyptus tree, how can human arrogance dare deny its reality under the blindness of dogma?

Indeed, the exploration of deep time is one of the most powerful elements in Sussman’s work — certainly a scientific concept, in terms of being concerned with biology, geology, and astrophysics, but also very much a philosophical one raising enormously important, if unsettling, existential questions: Why are we here? How can we matter if we’re gone in the blink of a cosmic eye, the metaphorical minute of a Bristlecone Pine’s day? And, most importantly, what gives us the arrogance to consider ourselves atop the hierarchy of living organisms? We extol our intelligence as the uniquely human faculty that sets us apart from other animals, but even our definitions of intelligence are narrowly anthropocentric and based on things we humans happen to be good at. Surely there’s a special kind of biological and existential intelligence in an organism capable of such remarkable resilience — an organism that can outlive us by millennia and witness all of our fleeting struggles while it remains unflinchingly rooted in its particular corner of the ecosystem.

Soil sample containing Siberian actinobacteria

400,000-600,000 years | Kolyma Lowlands, Siberia

Chestnut of 100 Horses with fresh lava

3,000 years | Sant'Alfio, Sicily

Because of its unique cross-disciplinary slant and dimensional scope, the book comes with two introductory essays — an art one by art-world legend and curator extraordinaire Hans Ulrich Obrist and a science one by Carl Zimmer, one of the finest and most respected science writers working today.

Obrist elegantly applies the late and great philosopher Eric Hobsbawm’s notion of “the protest against forgetting” to Sussman’s work and celebrates it as a living archive of remembrance. He writes:

The oldest living things may well not be a clear category science-wise, but it is a category that is defined by curiosity, humane character, a fascination with deep time, and the courage of an explorer.

In the science essay, Zimmer explores how lives become long and why the remarkable timescale of these organisms’ lifespans matters — not just scientifically, but also culturally:

The durable mystery of longevity makes the species in this book all the more precious, and all the more worthy of being preserved. Looking at an organism that has endured for thousands of years is an awesome experience, because it makes us feel like mere gastrotrichs. But it is an even more awesome experience to recognize the bond we share with a 13,000-year-old Palmer’s oak tree, and to wonder how we evolved such different lifetimes on this Earth.

Lower slope leading to Palmer's Oak

13,000 years | Riverside, California, USA

Box Huckleberry (Bibleberry) branches stripped by deer

8,000 to 13,000 years | Perry County, Pennsylvania, USA

Stromatolites

2,000-3,000 years | Carbla Station, Western Australia

Even more fascinating than how much we know, however, is how much we don’t — many of these organisms stand as a testament to the “thoroughly conscious ignorance” that drives science. In a book chapter exploring the 2,000-year-old Stromatolites of Western Australia — a species composed of bound cyanobacteria that formed about 3 billion years ago and undertook the Herculean task of oxygenating our then-oxygen-poor planet — Sussman observes:

It’s remarkable that we know so little about the origins of life on our planet. We know more about surfaces of other planets than we do about the beginnings of life on our own.

The Senator (bald cypress)

3,500 years | Seminole County, Florida

One of the most moving stories in the book is that of the Senator tree in Florida, one of the oldest Cypress trees in the world, which Sussman originally wrote for Brain Pickings a few years ago. She had photographed the Senator in 2007, but upon developing the film — Sussman shoots with a medium-format film camera for her high-quality fine art prints — she found herself unhappy with the result and resolved to return to the tree down the line. Since it was one of the most easily accessible organisms in her stable — what’s a sunny flight to Florida next to a harrowing weeklong voyage to Antarctica’s icy cliffs? — and since the tree had been around for 3,500 years, she figured it could wait.

Then, in January of 2012, news broke that a mysterious fire had burned the Senator to the ground. Unsettled and full of unease, Sussman immediately got on a plane to shoot the charred remains of the mighty tree, the only sign of its former brush with Forever. She poignantly observes:

Extreme longevity can lull us into a false sense of permanence. We fall into a quotidian reality devoid of long-term thinking, certain that things which have been here “forever” will remain, unchanging. But being old is not the same as being immortal. Even second chances have expiration dates. The comparative ease of access and the seeming lack of urgency bred a complacency in my return to the Senator.

The charred remains of the Senator Tree, February 8, 2012

The most devastating part? It was later discovered that the cause of the fire was a group of twenty-somethings who had broken into the park after dark, high on meth, climbed inside the tree, and lit matches or a lighter to “see the drugs better,” setting the Senator ablaze and erasing thousands of years of natural wisdom under the influence of synthetic senility.

But this story, too, is one of optimism. Sussman writes:

For the Senator, there is a chance at a second life: clippings from the tree were taken years ago and successfully propagated in a nursery. In February 2013, after a careful root-stabilization process, a forty-foot grafted tree was successfully transplanted back into the Senator’s original spot and has already sprouted fresh growth and gained in height. Four artisans and several institutions were selected to make works honoring the Senator’s legacy. The stump has been incorporated into the playground area.

In this beautiful short trailer by filmmaker Jonathan Minnard offers glimpse of Sussman’s extraordinary world:

Interwoven with Sussman’s photographs and essays, brimming with equal parts passion and precision, are the stories of her adventures — and misadventures — as she trekked the world in search of her ancient subjects. From a broken arm in remote Sri Lanka to a heart-wrenching breakup to a well-timed sip of whisky at polar explorer Shackleton’s grave, her personal stories imbue the universality of the deeper issues she explores with an inviting dose of humanity — a gentle reminder that life, for us as much as for those ancient organisms, is often about withstanding the uncontrollable, unpredictable, and unwelcome curveballs the universe throws our way, and that resilience comes from the dignity and humility of that withstanding.

Antarctic moss

5,500 years | Elephant Island, South Georgia

The Oldest Living Things in the World is absolutely remarkable in its entirety — a true masterpiece of compassionate curiosity and cross-disciplinary brilliance. A limited collectors’ edition is also available, housed in a gorgeous handcrafted, cloth-encased box, including a signed print of the Spruce image on the cover.

For more, see Sussman’s 2010 TED talk:

All photographs © Rachel Sussman published exclusively with the artist’s permission

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11 APRIL, 2014

The Science of Mood in Animals: Can Pets Be Depressed?

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The science behind what every pet-parent knows.

“What were the secrets of the animal’s likeness with, and unlikeness from man?” John Berger pondered in his influential meditation on our relationship with animals. “The secrets whose existence man recognized as soon as he intercepted an animal’s look.” And yet for all the progress we’ve made, for all the advances afforded us by pioneering animal scientists like Jane Goodall, we still struggle to understand — or, in some cases, even acknowledge — the inner lives and emotional realities of our fellow non-human beings. Despite what every pet-parent sees with absolute clarity in watching, say, her dog whimper with agonizing anxiety or greet a friend with exquisite elation, the question of animal emotionality is still, perplexingly, something of a taboo.

In The Depths: The Evolutionary Origins of the Depression Epidemic (public library) — his fascinating exploration of how mood science illuminates “the unaddressed business of filling our souls” — psychologist Jonathan Rottenberg addresses this paradox:

Depression in animals has long been a hard sell. In the wake of René Descartes, an enormous gulf opened between humans and other species, and Cartesian thinkers ever since have argued that other animals are mere automata, furry robots. Skepticism about complex inner states in other species has endured even into the twenty-first century. The torch has been passed from behaviorists, who wanted to banish all notions of motivation from scientific purview, to contemporary neuroscientists, who accepted basic motivational drives but not anything as elusive as animal feelings, and finally to cultural psychologists, who have no place for animal depression, but for different reasons. For them, depression is a shared understanding, a historical artifact defined by human words and deeds.

Mood science seeks to refute these views… Our fellow mammals, be they rats, cats, or bats, provide the most compelling and dramatic evidence for depression in the animal kingdom. High and low moods equip these animals to track opportunities and resources in their environments; the capacity for mood is essential for guiding behavior in a changing world.

Illustration by Wendy MacNaughton based on Gay Talese. Click image for more.

Much like the human version, Rottenberg argues that depression in animals spans the full spectrum of severity, from brief and shallow periods of low mood to long and intense stretches of depression. Animals also experience the same hormonal changes that depressed humans do, including higher secretion of steroid hormones and dampened immune system function. Perhaps most interestingly and indicatively, the body clocks of depressed animals — their circadian rhythms, which we already know are of tremendous importance to human well-being — are so disrupted that they produce the same irregularities in body temperature and sleep-wake cycle seen in depressed humans. Rottenberg adds:

Beyond the official symptoms of human depression, dogs and cats manifest numerous unofficial signs that are characteristic of depressed humans. Those who live with them know that reduced exploratory behavior, long hours hiding under the bed, and reduced interest in self-care and personal hygiene, reflected in less grooming or use of a litter box, are all signs that something is amiss.

In a heartbreaking illustration of my longtime lament that there is no nuance in news today, Rottenberg points out a particularly ungenerous and gratuitously one-note instance of how the popular media tends to treat what’s clearly a complex subject:

Psychiatric problems in small animals are often trivialized, so it is easy for pet depression to fly under the radar. Fortune Magazine mocked Eli Lilly’s decision to pursue FDA approval of a chewable Prozac for pets as the second dumbest moment in business of 2007, writing, “Thank God. We’ve been so worried since Lucky dyed his hair jet black and started listening to the Smiths.”

Photograph by Tim Flach from his series 'More Than Human.' Click image for more.

Understanding non-human depression, Rottenberg reminds us, isn’t just a matter of compassion but might also hold important keys to better understanding, and treating, human depression, which is what he explores further in the altogether fantastic The Depths. Sample it further here.

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10 APRIL, 2014

The Science of Smell: How the Most Direct of Our Senses Works

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Why the 23,040 breaths we take each day are the most powerful yet perplexing route to our emotional memory.

“Get a life in which you notice the smell of salt water pushing itself on a breeze over the dunes,” Anna Quindlen advised in her indispensable Short Guide to a Happy Life. Susan Sontag listed “linen” and “the smell of newly mown grass” among her favorite things. “A man may have lived all of his life in the gray,” John Steinbeck wrote in his beautiful meditation on the meaning of life, “and then — the glory — so that a cricket song sweetens his ears, the smell of the earth rises chanting to his nose.” Why is it that smell lends itself to such poetic metaphors, sings to us so sweetly, captures us so powerfully?

That’s precisely what science historian Diane Ackerman explores in A Natural History of the Senses (public library), her 1990 prequel to the equally fantastic A Natural History of Love. Ackerman, who also happens to be a spectacular poet and the author of the gorgeous cosmic verses that Carl Sagan mailed to Timothy Leary in prison, paints the backdrop of this perplexing and unique sensory experience:

Our sense of smell can be extraordinarily precise, yet it’s almost impossible to describe how something smells to someone who hasn’t smelled it… We see only where there is light enough, taste only when we put things into our mouths, touch only when we make contact with someone or something, hear only sounds that are loud enough to hear. But we smell always and with every breath. Cover your eyes and you will stop seeing, cover your ears and you will stop hearing, but if you cover your nose and stop smelling, you will die.

Illustration by Wendy MacNaughton from 'The Essential Scratch and Sniff Guide to Becoming a Wine Expert.' Click image for more.

In fact, every breath we take in order to live is saturated with an extraordinary amount of olfactory information — a fact largely a matter of scale:

Each day, we breathe about 23,040 times and move around 438 cubic feet of air. It takes us about five seconds to breathe — two seconds to inhale and three seconds to exhale — and, in that time, molecules of odor flood through our systems. Inhaling and exhaling, we smell odors. Smells coat us, swirl around us, enter our bodies, emanate from us. We live in a constant wash of them. Still, when we try to describe a smell, words fail us like the fabrications they are…

The charm of language is that, though it is human-made, it can on rare occasions capture emotions and sensations that aren’t. But the physiological links between the smell and language centers of the brain are pitifully weak. Not so the links between the smell and the memory centers, a route that carries us nimbly across time and distance.

Indeed, that route is a greater shortcut to our cognition and psychoemotional circuitry than any of our other senses can offer. Ackerman outlines the singular qualities of our smell-sensation that set it apart from all other bodily functions:

Smell is the most direct of all our senses. When I hold a violet to my nose and inhale, odor molecules float back into the nasal cavity behind the bridge of the nose, where they are absorbed by the mucosa containing receptor cells bearing microscopic hairs called cilia. Five million of these cells fire impulses to the brain’s olfactory bulb or smell center. Such cells are unique to the nose. If you destroy a neuron in the brain, it’s finished forever; it won’t regrow. If you damage neurons in your eyes or ears, both organs will be irreparably damaged. But the neurons in the nose are replaced about every thirty days and, unlike any other neurons in the body, they stick right out and wave in the air current like anemones on a coral reef.

Illustration by Tomi Ungerer from 'The Cat-Hater's Handbook.' Click image for more.

That’s also what makes perfumes so powerful — if you’ve ever walked into a crowded room and instantly experienced a pang of emotion as you thought you smelled your ex, or your mother, or your third-grade teacher, you’ve had a first-hand testimony to the potency of smell as a trigger of emotional memory. Ackerman explains:

A smell can be overwhelmingly nostalgic because it triggers powerful images and emotions before we have time to edit them… When we give perfume to someone, we give them liquid memory. Kipling was right: “Smells are surer than sights and sounds to make your heart-strings crack.”

What’s perhaps most extraordinary is that scent lodges itself largely in the long-term memory system of the brain. And yet, we remain inept at mapping those links and associative chains when it comes to describing smells and their emotional echoes. To shed light on how perfumery plays into this paradox, Ackerman offers a taxonomy of the basic types of natural smells and how they became synthetically replicated, unleashing an intimate dance of art, science, and commerce:

All smells fall into a few basic categories, almost like primary colors: minty (peppermint), floral (roses), ethereal (pears), musky (musk), resinous (camphor), foul (rotten eggs), and acrid (vinegar). This is why perfume manufacturers have had such success in concocting floral bouquets or just the right threshold of muskiness or fruitiness. Natural substances are no longer required; perfumes can be made on the molecular level in laboratories. One of the first perfumes based on a completely synthetic smell (an aldehyde) was Chanel No. 5, which was created in 1922 and has remained a classic of sensual femininity. It has led to classic comments, too. When Marilyn Monroe was asked by a reporter what she wore to bed, she answered coyly, “Chanel No. 5.” Its top note — the one you smell first — is the aldehyde, then your nose detects the middle note of jasmine, rose, lily of the valley, orris, and ylang-ylang, and finally the base note, which carries the perfume and makes it linger: vetiver, sandalwood, cedar, vanilla, amber, civet, and musk. Base notes are almost always of animal origin, ancient emissaries of smell that transport us across woodlands and savannas.

And so we get to the actual science of smell — what actually makes us have an olfactory experience, and why we often confuse those with taste:

We need only eight molecules of a substance to trigger an impulse in a nerve ending, but forty nerve endings must be aroused before we smell something. Not everything has a smell: only substances volatile enough to spray microscopic particles into the air. Many things we encounter each day — including stone, glass, steel, and ivory — don’t evaporate when they stand at room temperature, so we don’t smell them. If you heat cabbage, it becomes more volatile (some of its particles evaporate into the air) and it suddenly smells stronger. Weightlessness makes astronauts lose taste and smell in space. In the absence of gravity, molecules cannot be volatile, so few of them get into our noses deeply enough to register as odors. This is a problem for nutritionists designing space food. Much of the taste of food depends on its smell; some chemists have gone so far as to claim that wine is simply a tasteless liquid that is deeply fragrant. Drink wine with a head cold, and you’ll taste water, they say. Before something can be tasted, it has to be dissolved in liquid (for example hard candy has to melt in saliva); and before something can be smelled, it has to be airborne. We taste only four flavors: sweet, sour, salt, and bitter. That means that everything else we call “flavor” is really “odor.” And many of the foods we think we can smell we can only taste. Sugar isn’t volatile, so we don’t smell it, even though we taste it intensely. If we have a mouthful of something delicious, which we want to savor and contemplate, we exhale; this drives the air in our mouths across our olfactory receptors, so we can smell it better.

Illustration by Wendy MacNaughton from 'The Essential Scratch and Sniff Guide to Becoming a Wine Expert.' Click image for more.

The rest of A Natural History of the Senses is just as fascinating a read, diving deeper into the mysteries and miracles of smell and our other sensory faculties. Complement it with Ackerman’s A Natural History of Love and her impossibly wonderful love letter to the Solar System, The Planets: A Cosmic Pastoral.

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08 APRIL, 2014

The Science of How Memory Works

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What the four “slave” systems of the mind have to do with riding a bicycle.

“Whatever becomes of [old memories], in the long intervals of consciousness?” Henry James wistfully pondered upon turning fifty. “They are like the lines of a letter written in sympathetic ink; hold the letter to the fire for a while and the grateful warmth brings out the invisible words.” James was not alone in seeking to understand the seemingly mysterious workings of human memory — something all the more urgently fascinating in our age of information overload, where we’re evolving a new kind of “transactive memory.” But like other scientific mysteries of how the brain works — including what actually happens while we sleep and why some people are left-handed — memory continues to give scientists more questions than answers.

In The Guardian of All Things: The Epic Story of Human Memory (public library) technology writer Michael S. Malone takes a 10,000-year journey into humanity’s understanding of our great cognitive record-keeper, exploring both its power and its ongoing perplexity.

Illustration from 'Neurocomic,' a graphic novel about how the brain works. Click image for more.

One of the most astounding facts Malone points out is that memory — that is, the creation of memories — is the result of a biochemical reaction that takes place inside neurons, one particularly common among neurons responsible for our senses. Scientists have recently discovered that our short-term memory — also known as “working memory,” the kind responsible for the “chunking” mechanism that powers our pattern-recognition and creativity — is localized to a few specific areas of the brain. The left hemisphere, for instance, is mostly in charge of verbal and object-oriented tasks. Even so, however, scientists remain mystified by the specific distribution, retrieval, and management of memory. Malone writes:

One popular theory holds that short-term memory consists of four “slave” systems. The first is phonological, for sound and language that (when its contents begin to fade) buys extra time through a second slave system. This second operation is a continuous rehearsal system — as you repeat a phone number you’ve just heard as you run to the other room for your phone. The third system is a visuo-spatial sketch pad that, as the name suggests, stores visual information and mental maps. Finally, the fourth (and most recently discovered) slave is an episodic buffer that gathers all of the diverse information in from the other slaves, and maybe other information from elsewhere, and integrates them together into what might be described as a multimedia memory.

It’s worth noting that memory and creativity have a great deal in common — the combinatorial process of memory-making that Malone describes is remarkably similar to how creativity works: we gather ideas and information just by being alive and awake to the world, record some of those impressions in our mental sketch pad, then integrate the various bits into new combinations that we call our “own” ideas, a kind of “multimedia” assemblage of existing bits.

Malone goes on to explore the inner workings of long-term memory — a substantially different beast, designed to keep our permanent mental record:

Chemically, we have a pretty good idea how memories are encoded and retained in brain neurons. As with short-term memory, the storage of information is made possible by the synthesis of certain proteins in the cell. What differentiates long-term memory in neurons is that frequent repetition of signals causes magnesium to be released — which opens the door for the attachment of calcium, which in turn makes the record stable and permanent. But as we all know from experience, memory can still fade over time. For that, the brain has a chemical process called long-term potentiation that regularly enhances the strength of the connections (synapses) between the neurons and creates an enzyme protein that also strengthens the signal — in other words, the memory — inside the neuron.

From the functional, Malone moves on to the structural organization of memory, where another dichotomy emerges:

Architecturally, the organization of memory in the brain is a lot more slippery to get one’s hands around (so to speak); different perspectives all seem to deliver useful insights. For example, one popular way to look at brain memory is to see it as taking two forms: explicit and implicit. Explicit, or “declarative,” memory is all the information in our brains that we can consciously bring to the surface. Curiously, despite its huge importance in making us human, we don’t really know where this memory is located. Scientists have, however, divided explicit memory into two forms: episodic, or memories that occurred at a specific point in time; and semantic, or understandings (via science, technology, experience, and so on) of how the world works.

Implicit, or “procedural” memory, on the other hand, stores skills and memories of how to physically function in the natural world. Holding a fork, driving a car, getting dressed — and, most famously, riding a bicycle — are all nuanced activities that modern humans do without really giving them much thought; and they are skills, in all their complexity, that we can call up and perform decades after last using them.

One of the most confounding pieces of the cognitive puzzle, however, is a form of memory known as emotional memory — a specialized system for cataloging our memories based on the emotions they evoke. It’s unclear whether it belongs to the explicit or implicit domain, or to both, and scientists are still seeking to understand whether it serves as a special “search function” for the brain. (What we do now know, however, is that sharpening “emotional recall” might be the secret to better memory.)

From all this perplexity emerges Malone’s bigger point, a somewhat assuring testament to the idea that science, at its best, is always driven by “thoroughly conscious ignorance”:

What we do know is that — a quarter-million years after mankind inherited this remarkable organ called the brain — even with all of the tools available to modern science, human memory remains a stunning enigma.

The Guardian of All Things is a fascinating read in its entirety. Complement it with Joshua Foer’s quest to hack memory to superhuman levels and Henry James on aging and memory.

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