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Statusticians

[ 4 ] April 25, 2010

by Sam McDougle

A young physics graduate student is sitting at a table of undergrads.  He is telling a joke about mathematicians.

He begins confidently. “How can you tell when a mathematician is an extrovert?

A wide-eyed sophomore quickly asks “I dunno…how?”

Smiling, he replies, “He looks at your shoes when talking to you!”

The undergrads chuckle.  Some genuinely laugh, others pretend to get it.  The grad student relishes in his successful attempt at humor – the students are putty in his hands.  Suddenly, his gratification is interrupted when a prolifically published professor joins the table and, with a penetrating squint asks what joke he missed.

The grad student, who greatly admires his superior’s accomplished reputation (though barely knows him) becomes stressed, blushes and fumbles over the joke.  The professor giggles in an act of mercy, nods at the enthralled undergrads, and hastily moves on.

We can all relate to situations like these – when poise quickly turns to angst at the mere presence of a superior.

Humans, like many other primates, live in a social hierarchy.  This hierarchy exists in all areas of our lives: our families, schools, neighborhoods, and workplaces (academia struck me as a noteworthy example, thus, the above vignette).  We continually jockey between positions of dominance and subordination, and our emotions, thoughts, and behaviors seem to be at the mercy of this balancing act.  So it’s no surprise that new research reveals a vast neurological divergence when we’re confronted with, respectively, “superior” and “inferior” individuals.

Consider this article by Caroline Zink et al, published in the most recent issue of Neuron.  The researchers used a simple competitive task (i.e. clicking a blue circle as soon as it changed color) to establish an experimental, skill-based hierarchy (clicking faster = better) among participating subjects (Zink et al, 2010).

The subjects were pitted against two competitors, and all three were ranked relative to each other.  Each task consisted of three phases: viewing a photo of one of the other players, playing the game, and viewing the outcomes. FMRI readings were taken to measure brain activity during the tasks.  (note – while this experimental “social” situation may seem unnaturally plain, it succeeds in focusing in on the very common scenario of an inferior-middle-superior hierarchy).

Their results characterized greater activation in several important brain regions at the sight of a superior individual compared with an inferior one:

“Brain activity when viewing a more superior player compared with viewing a more inferior player was significantly greater in occipital/parietal cortex, ventral striatum, and parahippocampal cortex, implicating these brain areas in the neural encoding of hierarchical rank.”

These structures (specifically, the occipital/parietal cortex and ventral striatum) have been correlated with greater attentional processing.  The medial prefrontal cortex, an area cited for its role in social cognition (especially an individual’s status relative to others) exhibited heightened activity when the player was confronted with a superior, as did vital emotional processing areas (i.e. the amygdala).  In other words, peers representing an “inferior” role in a given social hierarchy represent an “inferior” role in the brain as well.

The author’s made another intriguing finding by conducting a control experiment where the “rank” of each player stayed static regardless of their performance in the game. It turned out that the prospect of rank mobility (analogous to “social mobility?”) had a strong effect on the heightened brain activity linked to confronting a superior.  The potential to “overtake” a superior player (or be overtaken yourself) made the brain work harder in the areas mentioned above.

These results paint a familiar picture:  When faced with a superior, our emotions are heightened, our attention sharpened, and our social position closely analyzed.  This effect is amplified in situations where your own status is subject to change.  Think of the last time you met a superstar in your field or an artist you greatly admire.  Did their status not stir your emotions? Did you find yourself paying close attention to your words while carefully tracking their reactions?  Did you, on leaving the encounter, dwell on the possible social advantages or disadvantages gleaned from the confrontation?  If your answer to these questions is unequivocally no, I would guess you are either being untruthful or have a rare, and somewhat enviable, phenotype rendering you apathetic to status.

***

Zink’s model certainly carries over to our primate cousins. Baboons closely watch their superiors and often ignore their inferiors. They also exhibit increased stress when their hierarchies are in flux (especially individuals in superior positions).  Chimps are very sensitive to hierarchical structure as well.

Even though we often want to avoid these feelings and conceal any interest in social status (“I don’t care what people think about me!”), I believe we’re stuck with our status fascination.  This data seems to say we’re built for it.

It would be remiss to not mention human variability in these behaviors. There are certainly individual differences when it comes to one’s feelings about status – we label some individuals as persistent “social climbers,” and other’s as “shoegazers” (*subcategories: those who gaze at their own shoes and those who gaze at yours).  Differences aside, our fixation on status is clearly reflected in the brain – we may not all be mathematicians, but, like it or not, we are all statusticians.

Portrait of Philip II, King of Spain

The “Haha” Moment

[ 10 ] April 5, 2010

by Sam McDougle

Where did humor come from?

“I would never want to belong to any club that would have someone like me for a member.”

The famous Groucho Marx-via-Woody Allen witticism packs a comedic punch rivaled by few other one-sentence quips.  The joke manages to conjure both chuckle-worthy humor and poignant commentary on familiar truths about self-esteem (like much of Allen’s Annie Hall).

But what makes this line funny?

What is “funny”?

The human sense of humor is a mystery.  It’s no surprise that humor is referred to as a “sense” – Like other senses, Humor is a pan-human trait that seems to be an integral part of human biology and has been so through all recorded human history.  Some form of humor exists in all cultures, in every corner of the world.  What would a gathering of friends be without a laugh?  A Thanksgiving dinner without amusing family dirt?  Can a date go well without a successful joke?

Theories concerning the evolution of humor abound.  Linguist/psychologist Steven Pinker has argued that humor is a mechanism to assert oneself in social relationships and strengthen bonds.  Geoffrey Miller of the University of New Mexico thinks it is a display of attractive cognitive abilities, designed to charm potential mates.   Aristotle contended that humor exists as a means for us to laugh at others and establish superiority.

Theories like this are interesting, but merely offer descriptions of the ultimate function of humor – they do not give us insight into why specific utterings are, by definition, humorous.  How does simply substituting the “me” for “you” in Allen’s above quote quickly turn a funny one-liner into a dry declaration of spite?

A young anthropologist at UCLA has recently made a compelling attempt to address the issue.  Thomas Flamson argues that humor is a way for an individual to convey “encrypted” information, and “functions as an honest signal of the fact of common knowledge, attitudes, and preferences.”  To Flamson, “getting the joke” is, oddly enough, the reason why the joke is funny in the first place.  This may seem circular but it works – perhaps we feel joy, manifested in laughter, from humor because we are pleased with ourselves for having the knowledge needed to “get it.”

Flamson illustrated this idea with an experiment.  He showed subjects this pictorial one-liner from the online humor magazine The Onion.  One version displayed the cartoon with a paragraph that described Frank Gehry’s work (“he is best known for building curved, unevenly-shaped buildings…”), while another version had a control paragraph of equal length that merely described where Gehry was born and raised.   Subjects were grouped according to their previous knowledge of Gehry’s quirky work.

Subjects whom already knew about Gehry’s architecture found the first version (the one that did not explain his abstract tendencies) significantly funnier.  If the subject did not previously know about his work, they found the explained version much funnier.  In other words, the knowledge required to “get” the joke – to acknowledge the impractical silliness of an abstractly erected Gehry-esque ham sandwich – predicts its funniness. Jokes are, as Flamson perceptively affirms, “purposefully oblique.”

Flamson theorizes about a universal function of humor as well.  By encrypting nuggets of knowledge (i.e. facts about famous architects) in jokes, we can pinpoint people who have important similarities to us – after all, “knowledge” is a good indicator of upbringing, values, and cultural status:

“Humor could have evolved as a tool that allowed ‘cognitively similar’ individuals to identify each other and assort, leading to the fitness benefits that accrue to individuals that successfully solve problems of coordination and cooperation.”

Additionally, our superlative ability to spot and produce fake laughter could be viewed as an important behavioral fail-safe/means of deception.

The encryption theory will hopefully inspire more research, as it is the most convincing theory of humor I’ve come across.  After reading Flamson’s article, I was compelled to ask him why puns are funny — Why are some jokes accessible to almost everyone who speaks a given language if humor evolved as a precise sorting device?

His response to my query hit on an important point:  He wrote that it is important to “draw a distinction between the ‘proper domain’ of an adaptation (the set of things it was selected to act on) and the ‘actual domain’ (the set of things humans use it for in the modern environment), where the actual usually has a considerably broader range than the proper.”

In other words, certain “adaptive” behaviors have been manifested in the modern environment beyond their basic original function (i.e. human eye-hand coordination and video gaming). Perhaps puns are a “watered-down,” low-value signal of weakly encrypted common knowledge, and are thus a rather ineffective social sorting tool (this also explains why puns often elicit groans instead of laughs).

Ultimately, it will be interesting to see how the study of humor progresses.  While the dissection of jokes may seem to ruin them for some, it is nonetheless an intriguing practice.

***

Perhaps we can add another layer to Woody Allen’s onion – In a turn of irony, musing on his disinterest in clubs that seek his own membership, the narrator obliquely recruits the listener to join his.Hals_Malle_Babbe

To Sleep, Perchance To Eat

[ 3 ] March 21, 2010

Why do organisms sleep?

“Methought I heard a voice cry, “Sleep no more!
Macbeth does murder sleep!” the innocent sleep,
Sleep that knits up the ravelled sleave of care,
The death of each day’s life, sore labor’s bath,
Balm of hurt minds, great nature’s second course,
Chief nourisher in life’s feast.”

Macbeth spoke these words to his lady with strained desperation as he brooded over his murderous deed.  Sleep is a curious contradiction – slumber is both vulnerable and comforting.  However, assuming you’re not wrapped up in any malicious political assassination plots, it’s more often the latter.

The “how” of sleep has been widely researched – from the progression of the stages of “slow-wave” sleep and the details of deep slumber (REM), to the heavy physical and cognitive impairments resulting from sleep deprivation.

The “why” of sleep is more of a mystery.  There are countless theories about the purpose of sleep. It has been implicated in the secretion of vital hormones, neurogenesis (the creation of new neurons), memory consolidation, and immune system optimization.  However, in a recent article in Nature’s special review issue celebrating Darwin’s 200th birthday, Jerome Siegel of UCLA argues that these effects of sleep don’t explain the considerable variation in sleep patterns across the animal kingdom.

Mammals range from less than 3 hours of REM sleep a day to more than 8 hours.  Some hibernate (brown bears, ground squirrels), while others seldom doze (giraffes, walruses).  Dolphins enter an intriguing REM imitation called “ultra slow-wave sleep,” where they alternate between brief bouts of lazy floating and slow swimming (though they remain very responsive to environmental stimuli).  When fur seals slumber deeply they turn off one hemisphere of their brain at a time, with one flipper keeping balance while the other remains motionless.

Non-mammals show similar levels of variation.  White-crowned sparrows sleep very little, and sometimes not at all when they’re migrating.  Hummingbirds enter a hibernation-like state called “torpor,” which is marked by a relatively short period of extremely low metabolism (think of it as a shorter but more “turned-off” hibernation).  Reptiles have not been definitively shown to enter REM sleep, and their sleeping habits are often dependent on temperature.  Even non-animals exhibit sleep-like behaviors – many deciduous trees are dormant in certain seasons, parasites often enter suspended cystoid phases during their life cycle, and one species of yeast was brought back from a 45 million year slumber and brewed into a beer.

Siegel’s argument is that the variation mentioned above (which is a small sample of the data he cites) makes it unlikely that sleep has some widely-applicable neurological function, which is a common belief.  Bears have unexceptional immune systems, but go into wildly long periods of deep hibernation. Lizards can learn and have memories, but show no REM sleep at all.  Dolphins don’t have growth hormone deficiencies, but are moving around their entire life.  Trees certainly don’t have neurogenesis (or any neurons at all) but enter states of seasonal sleep-like dormancy.

***

There are certain obvious functions of sleep that work across species and explain variation.  When sleeping, animals remain in one spot, thus decreasing the chance of running into a hungry predator and this defense mechanism is especially practical when the animal sleeps in a protected cave or nest (perhaps King Duncan should have taken a cue from these animals).  Furthermore, one aspect of sleep is absolutely universal across all living things – it saves energy.  Siegel likens sleep to “turning off the lights” when you leave a room – animals only want to spend the energy they need to spend to carry out vital behaviors (eating, mating, rearing children, etc).  The more energy the animal burns, the more it needs to be out and about foraging for food, at risk for both predation and starvation.  This idea is supported by the variation of sleep patterns in the animal kingdom, and these patterns are dependent on environmental factors – brown bats sleep 20 hours a day to avoid bird predation and they forage vigorously for the other 4, Giraffes sleep very little as they need to keep moving to avoid open-plain predation and eat plenty of low-nutrition flora, and lions sleep most of the day to conserve vigor for the demanding hunt.

Sleep is an energy saving mechanism, or as Siegel puts it, “adaptive inactivity.”  It may be a rather simple answer to the “why we sleep” question, but it covers the bases and makes convincing adaptive sense:

“Why would some species need so much more of the mysterious restorative process that has been proposed to determine sleep duration than other species?…Sleep is best understood as a variant of dormant states seen throughout the plant and animal kingdoms and that is itself highly adaptive because it optimizes the timing and duration of behavior.”

That is not to say the other proposed functions of sleep aren’t significant, but they are less likely to be the reason sleep evolved in the first place.  Simple energy conservation and risk avoidance tell a compelling story – sleep is, above all, the “Chief nourisher in life’s feast.”

I look forward to the unearthing of Dr. Shakespeare’s methodical research on the correlation of foraging patterns, food intake, and REM duration in soon-to-be assassinated medieval Scottish kings.

I Feel Your Pain

[ 1 ] March 4, 2010

New research on fear learning and the experience of pain

I can imagine the gasps emitted in countless households when Sweden’s Anja Paerson wiped out on the women’s combined Alpine skiing event in Vancouver last month. Her long, violent tumble could not have felt good.

From watching sports and violent movies, to seeing your friend stub her toe, we’re regularly exposed to scenes of pain. We do not always take these scenes lightly – while we may laugh out of discomfort (or sometimes malice) we often empathize with the victims. In essence, we “feel their pain.”

It is known that when one witnesses another in pain, they experience fear. Just interview a crowd leaving a horror flick and they’ll tell you the same. However, the neurological mechanism behind learning to fear that which is not directly affecting you is a mystery (though the amygdala is surely involved…check out the work by last month’s podcast subject, Joe LeDoux).

A brand new study published in Nature Neuroscience sheds some light on this issue. It turns out that the region of the brain that responds to actually enduring something painful also responds to witnessing another’s pain. This response is hypothesized to facilitate fear learning.

Jeon et al (2010) designed an experiment wherein two mice sit across from each other in a cage separated by a translucent plastic window. One mouse was given electric shocks while the other looked on. As you would guess, the “observer” mouse was in visible fear as she watched, frozen in fright. The authors conducted electrophysiological experiments (using electrodes to measure neuronal activity) to see what was going on in various regions of the observer mouse’s brain during the sessions.

As the authors note, the amygdala surely plays a role in fear learning. The amygdala is responsible for behavioral reactions to emotionally relevant events or situations causing unpleasant consequences; indeed, the electrocution of a fellow mouse has much emotional relevance.

More interesting, however, is what was going on in other regions of the observer mouse’s brain. The anterior cingulate cortex (ACC) is known to play a role in the affective/emotional dimension of pain. In other words, it facilitates the feeling of being in pain rather than direct pain itself: If you get a paper cut, various thalamic nuclei produce the sensory aspects of pain – the feeling at the source on the sliced tip of your thumb – while the ACC gives you the affective aspect of pain, the unified whole-body experience. The ACC was noticeably active in the observer mice.

This is a very compelling finding. It suggests a mechanism by which we experience pain even when nothing is directly happening to our body. In effect, we use others as our “proxy” in order to learn what we should fear.

The story, in admittedly silly and fallaciously cognitive terms, goes something like this (parentheses here represent the most relevant neural processes/substrates):

“That guy’s in pain (sensory observation + amygdala)…Ouch, I’m now having a sensation of what that pain may be like (ACC)…I should be afraid of whatever threat is doing that to him (integration of amygdala, ACC and others; “fear learning”)…I’m getting the hell out of here! (behavioral result).”

The evolutionary advantages of this system – a system whereby a creature can learn to fear something based on its observed negative affects on the creature’s peers – are clear. The grave consequences of a failure or malfunction of this system are equally clear:

“Many aberrant social behaviors associated with psychiatric conditions, including various psychopathic or mental disorders (for example, post-traumatic stress disorders, schizophrenia, autism and dementia), feature impairment of recognition of the emotions and feelings of others and dysfunctions in the ACC have been associated with these psychiatric conditions (Jeon et al, 2010).”

***

Perhaps we really do feel each other’s pain. Perhaps the customary “ouch!” we emit when strangers cut their fingers, movie stars get eviscerated, or downhill skiers take hard falls, reflects a sincere exclamation of pain, not just a cultural meme.   When Ms. Paerson crashed I may have felt it too…that would certainly make sense of my fear of double black diamonds.

Beauty Isn't Meninges Deep

[ 0 ] February 12, 2010

Beauty Isn’t Meninges Deep

Neuroscientists on the looks of the brain and its parts

“Soft.”

“Squishy.”

“A convoluted mass of gray and white matter.”

It’s easy to view the brain as a soggy, somewhat repellent heap of warm biological pudding.  But when you really get inside the supple pink mass, layers of neurons (or “butterflies of the soul” as their discoverer Ramón y Cajal called them), gleaming axons, branching dendrites, and countless complex sub-structures reveal the brain’s undeniably exquisite (and ancient) architecture.

Studying the brain is somewhat like studying astrophysics;  Investigators are burdened with the task of picking apart a complex universe of myriad micro and macro forms about which they know relatively little.  The gaps in knowledge start with the very small (i.e. does neuron X interact with neuron Y through electrical coupling or a chemical synapse?  Is it inhibitory or excitatory? etc…) and inflate as the lens gets wider (What is going on in Alzheimer’s disease? What is sleep for?  How are reflexes timed?).  There is no Einsteinian figure that has provided a binding theoretical foundation that illuminates the functioning of the brain, and, like quantum physics, some fields leave remarkably much to be desired (what the hell is “Consciousness?”).

Neuroscientists are often forced to decide which area of the brain to study early in their careers.  While they aren’t destined to choose one spot and stick to it, they often find themselves consumed by a single region of choice, lightheartedly pointing out its superlative qualities at dinner parties and lab meetings.  Many factors go into the decision.  Some areas, like the neocortex, offer appealing theoretical conundrums about “higher order” cognitive processing, thinking, and identity.  Others have been implicated in debilitating, unhealthy behavioral patterns (i.e. the insula and addiction) and may thus appeal to the more righteous of the brainoids – those who tirelessly look for cures and neurological therapies.  Those interested in sexual behavior have a handful of choices as well (the caudate nucleus, the amygdala, anterior cingulate cortex, etc).

Nevertheless, it often seems as though researchers are drawn to certain aesthetic aspects of brain regions, even if the functional aspects are of primary interest.

***antenna neurons

At a recent lecture I attended at the University of Pennsylvania, the gifted neuroscientist Rachel Wilson commented on the remarkable “order” of vertebrate chemosensory neurons before she spoke about her research on sensory processing in the fruit fly olfactory system. The neurons that line the fruit fly’s antennal lobe are positioned in a tight, repeated pattern.  Wilson often publishes gorgeously stained photos of the chemosensory neurons of the fruit fly antenna, such as the one seen here to the right– and she’s clearly drawn to their visual splendor.

“Order,” it seems, is an attractive attribute.  Javier Medina (the neuroscientist I work for) of The University of Pennsylvania often champions the coral-like, tightly-folded cerebellum for its functional worth as well as its graceful, structured beauty.

L7cerebellum.gif

“Confocal micrograph from a cerebellum expressing green-fluorescent protein in Purkinje cells”: The bright green circles are the cell bodies and the middle area shows their parallel axons.

Medina recently disclosed to me one reason why he studies the cerebellum instead of the ever-popular cortex:  ” [in the cortex] More than anything, you find silent cells…cells that don’t like to talk much, fire an electrical impulse here or there, but for the most part, keep quiet. For all the hoopla about it, the cortex is a sort of boring place… but if you dig your electrodes deeper, you’ll discover a neurophysiologist’s wonderland.  The cerebellum is never silent.”  The cerebellum is an exciting place indeed, with its “star-like stellate cells,” illuminating chandelier cells, and “gazillions of little granule cells, packed together like sardines.”  Furthermore, Dr. Medina is from Spain, and cites Cajal, his compatriot, as a “hero” and a “genius.” Cajal tackled the cerebellum – below is his skillfully detailed sketch of the cerebellum’s Purkinje cells, with their characteristic labyrinthine trellis of interlaced dendrites:

The unique appearance of certain brain regions has sometimes played a role in their naming. The hippocampus was given its distinctive moniker because of a physical resemblance to the sea horse, which itself shares a name with the half-horse, half-serpent creature of Greek Mythology.

Cajal’s Hippocampus

The structure of the enigmatic organ as a whole can actually be quite appealing as well.

changizibrains

The brain at the top is a common shrew's, the bottom a dolphin's. Note the "back bends" and the major differences in appearance.

Cognitive scientist and author Mark Changizi, of the Rensselaer Polytechnic Institute, alludes to the beauty found in the diversity of brains across species, writing, “brains differing by several orders of magnitude in size look so different that a visiting alien would have no idea they’re the same organ at all.”  His new research looks at the meandering twists and turns (“back bends”) that brain tissue must take in order to accommodate parallel increases in body and brain size across evolutionary time.  Those bends can be seen in the dolphin brain below, which he’s quick to describe as “gorgeous.”

***

From the iconic pop culture image of a brain in jar, to it’s oft-satirized role as zombie food, the brain is not usually known for its beauty.  But when we synthesize our knowledge of the organ’s extraordinary abilities with glances into its intricate inner architecture, the brain is revealed as a truly unequaled natural wonder.

Beauty Isn’t Meninges Deep

[ 0 ] February 12, 2010

Beauty Isn’t Meninges Deep

Neuroscientists on the looks of the brain and its parts

“Soft.”

“Squishy.”

“A convoluted mass of gray and white matter.”

It’s easy to view the brain as a soggy, somewhat repellent heap of warm biological pudding.  But when you really get inside the supple pink mass, layers of neurons (or “butterflies of the soul” as their discoverer Ramón y Cajal called them), gleaming axons, branching dendrites, and countless complex sub-structures reveal the brain’s undeniably exquisite (and ancient) architecture.

Studying the brain is somewhat like studying astrophysics;  Investigators are burdened with the task of picking apart a complex universe of myriad micro and macro forms about which they know relatively little.  The gaps in knowledge start with the very small (i.e. does neuron X interact with neuron Y through electrical coupling or a chemical synapse?  Is it inhibitory or excitatory? etc…) and inflate as the lens gets wider (What is going on in Alzheimer’s disease? What is sleep for?  How are reflexes timed?).  There is no Einsteinian figure that has provided a binding theoretical foundation that illuminates the functioning of the brain, and, like quantum physics, some fields leave remarkably much to be desired (what the hell is “Consciousness?”).

Neuroscientists are often forced to decide which area of the brain to study early in their careers.  While they aren’t destined to choose one spot and stick to it, they often find themselves consumed by a single region of choice, lightheartedly pointing out its superlative qualities at dinner parties and lab meetings.  Many factors go into the decision.  Some areas, like the neocortex, offer appealing theoretical conundrums about “higher order” cognitive processing, thinking, and identity.  Others have been implicated in debilitating, unhealthy behavioral patterns (i.e. the insula and addiction) and may thus appeal to the more righteous of the brainoids – those who tirelessly look for cures and neurological therapies.  Those interested in sexual behavior have a handful of choices as well (the caudate nucleus, the amygdala, anterior cingulate cortex, etc).

Nevertheless, it often seems as though researchers are drawn to certain aesthetic aspects of brain regions, even if the functional aspects are of primary interest.

***antenna neurons

At a recent lecture I attended at the University of Pennsylvania, the gifted neuroscientist Rachel Wilson commented on the remarkable “order” of vertebrate chemosensory neurons before she spoke about her research on sensory processing in the fruit fly olfactory system. The neurons that line the fruit fly’s antennal lobe are positioned in a tight, repeated pattern.  Wilson often publishes gorgeously stained photos of the chemosensory neurons of the fruit fly antenna, such as the one seen here to the right– and she’s clearly drawn to their visual splendor.

“Order,” it seems, is an attractive attribute.  Javier Medina (the neuroscientist I work for) of The University of Pennsylvania often champions the coral-like, tightly-folded cerebellum for its functional worth as well as its graceful, structured beauty.

L7cerebellum.gif

“Confocal micrograph from a cerebellum expressing green-fluorescent protein in Purkinje cells”: The bright green circles are the cell bodies and the middle area shows their parallel axons.

Medina recently disclosed to me one reason why he studies the cerebellum instead of the ever-popular cortex:  ” [in the cortex] More than anything, you find silent cells…cells that don’t like to talk much, fire an electrical impulse here or there, but for the most part, keep quiet. For all the hoopla about it, the cortex is a sort of boring place… but if you dig your electrodes deeper, you’ll discover a neurophysiologist’s wonderland.  The cerebellum is never silent.”  The cerebellum is an exciting place indeed, with its “star-like stellate cells,” illuminating chandelier cells, and “gazillions of little granule cells, packed together like sardines.”  Furthermore, Dr. Medina is from Spain, and cites Cajal, his compatriot, as a “hero” and a “genius.” Cajal tackled the cerebellum – below is his skillfully detailed sketch of the cerebellum’s Purkinje cells, with their characteristic labyrinthine trellis of interlaced dendrites:

The unique appearance of certain brain regions has sometimes played a role in their naming. The hippocampus was given its distinctive moniker because of a physical resemblance to the sea horse, which itself shares a name with the half-horse, half-serpent creature of Greek Mythology.

Cajal’s Hippocampus

The structure of the enigmatic organ as a whole can actually be quite appealing as well.

changizibrains

The brain at the top is a common shrew's, the bottom a dolphin's. Note the "back bends" and the major differences in appearance.

Cognitive scientist and author Mark Changizi, of the Rensselaer Polytechnic Institute, alludes to the beauty found in the diversity of brains across species, writing, “brains differing by several orders of magnitude in size look so different that a visiting alien would have no idea they’re the same organ at all.”  His new research looks at the meandering twists and turns (“back bends”) that brain tissue must take in order to accommodate parallel increases in body and brain size across evolutionary time.  Those bends can be seen in the dolphin brain below, which he’s quick to describe as “gorgeous.”

***

From the iconic pop culture image of a brain in jar, to it’s oft-satirized role as zombie food, the brain is not usually known for its beauty.  But when we synthesize our knowledge of the organ’s extraordinary abilities with glances into its intricate inner architecture, the brain is revealed as a truly unequaled natural wonder.

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