Nature’s Brains, Part 4

July 8, 2012

Bob Fiske

Nature’s Brains, Part 4

(Note: I invite you to read Part 3 before you dive into this part.)

Sooner or later, in nature’s tinkering with brain designs, a truly superior model was bound to come along.  The simian family lays claim to this prize.  Scientists don’t really understand how this happened, yet we see many descendent species alive today that clearly show the innovative features that formed over time.

One of these innovations was exquisitely fine motor control.  This capability appears to have co-evolved with body characteristics that could express new types of movement.  For instance, all monkeys and apes possess a finger-based hand that shapes itself with greater precision than is given to clawed or hooved mammals.  Also, some of these species are endowed with long limbs and tails that give them the arboreal advantage to swing, climb and hang.  Of course, living in trees also requires balance, eyesight and hearing to match the motor skills.  These are jobs handled by the new brain, and they couple well with this brain’s superior learning ability.

Courtesy of e-mail, I once watched a film of a gibbon teasing a pair of tiger cubs.  (You may watch it here, though be warned that the film quality is low.)  If ever I saw a gymnastic wizard, this little gibbon was it.  It is a remarkable testimony of the superior level of body-and-brain coordination possible using a simian brain.

Other capabilities emerged in the simian brain.  A brain that can learn is a brain that can teach.  Thus, it is possible to pass brain-encoded patterns from generation to generation without relying only on the DNA hard-wiring of behavior.  By the way, the teaching of new generations is not a monopoly owned just by simian brains.  Bears teach their cubs how to forage, and many types of young male birds must learn their songs from older males of the same species and geographic location.  Nonetheless—as we well know—the simian brain would push the ability to learn and teach to new heights.

The most recent brain innovations are sported by the hominids, or great apes.  Some of our less intellectual cousins, chimpanzees and gorillas, show that they, too, carry the seeds of the type of intelligence that flourished in the Homo (human) line.  Chimps have been observed to make simple tools such as using sticks to fish out ants from a nest for eating.  These species show other “human” traits such as problem-solving, concern for the welfare of others, and self-awareness.

And, surprisingly, both chimpanzees and gorillas have revealed that they possess previously unsuspected symbolic language skills.  Given the right expressive media (American Sign Language, computer screens or colored shapes), hominids in research settings have amassed sizeable vocabularies and have shown that they can fashion novel “utterances” to express, wants, needs and general observations.

Finally in this discussion of the “advanced design” hominid brain, I wish to mention a series of brain structures that are loosely bundled under the term “the limbic system”.  The limbic structures lie at the base of the cortex, at the juncture where it surrounds the “old brain”.  In fact, these structures (the hippocampus, the amygdala, the nucleus accumbens, and others) appear in other mammalian brains of less intellectual stature than the hominid brain.  In spite of this fact, it is probable that, in hominid brain design, limbic structures were enhance and pressed into service to perform more complex functions.  Limbic functions are thought to play a role in reward, fear, addiction, emotional memories and memory formation in general.  Perhaps that’s too much anatomy.

The idea I want to paint about the new-and-improved hominid brain might be better conveyed using broader brush strokes.  This brain permitted a new level of behavioral and thought patterns, patterns that were the product of emotions, punishments, rewards and social transactions.  In ape communities we see such things as exchanging grooming services, currying favor and shifting dominance hierarchies.  However, in human communities an entirely new social reality was called into existence.  Its final metamorphosis would be expressed in human culture.  In this culture the social, emotional, symbolic, political, artistic, economic and intellectual components could take on reality as  by-products of a marvelously large brain.

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Nature's Brains, Part 3

July 8, 2012

Bob Fiske

Nature’s Brains, Part 3

(Note: I invite you to read Part 2 before you dive into this part.)

As nature continued to tinker with brain designs, sooner or later some sophisticated features were bound to arise.  In larger, brained animals, such as dinosaurs, the reptilian or “old brain” did little more than regulate basic bodily processes.  These brains sent “down” nerve impulses for modifying respiration, digestion, heart rate, and perhaps even body temperature.  The old brain could also chain together primitive movements known as reflexes.  Reflexes are simple and are coded in the spinal cord.  Through the dominance of the brain these simple movements could be orchestrated into more complex behavioral sequences, sort of like composing words from the letters of the alphabet.

The complex behavioral sequences could accomplish tasks such as hunting, mating, building a nest, walking, running, fighting, and so on.  How did the old brain come to encode the complex behaviors?  Through trial-and-error.  In other words, species went extinct or found a survival advantage based upon the behavior sets that were genetically hard-wired into their members’ brains.  These behaviors were determined by the DNA code in that species’ genes and were passed from generation to generation.  Learning of the sort that we take for granted had not yet been invented as a brain design feature.

Even today we are able to see in the “advanced” mammalian brain vestiges of hard-wired, genetically coded behavior.  One example of this is the newborn foal.  Within minutes of being born, baby horses struggle to their feet and begin to walk.  Seeing a fully developed behavior of this sort is fairly unusual in the mammalian brain because the innovations it has acquired generally impose a long development period on the young brain.

One of the premier innovations that enabled mammals to survive was the brain’s ability to learn.  This is anything but trivial (even though we take it for granted).  In order to learn, the brain needed to have a memory that could be loaded with new patterns.  But, for that to happen, the brain required an exquisitely complex coding mechanism that could replicate, in a “neural form”, qualities of the real world, a virtual model, so to speak.  This required more and more neurons in the brain.  The result is the “new” brain, a larger accessory that physically sits above and around the old brain.  All this new neural tissue was crammed into a larger skull in a folded and wrinkled fashion.  Scientists call this the cortex.

Parts of the cortex could more richly record auditory information or visual information.  Also, parts of the cortex were dedicated to producing complex movement sequences in various muscle groups such as the limbs, the mouth, the tail, the vocal chords, etc.

By the way, mammalian brains exerted pressure on other species to keep up.  So, we see that many birds (the descendants of the dinosaurs) also innovated their brain designs in similar fashion.  Maybe we mammals are not so special, after all, just lucky to come out in front of the race for survival.

Of course all this ability to encode a rich a faithful inner world model or command exquisitely complex movements would be better utilized if the brain were endowed with an equally rich storage system, that is, a memory.  The memory would allow multiple experiences in an individual’s life to be compared.  This is essential to learning (and survival), for it enables the search for cause-and-effect relationships to be found.

Here’s a simple example.  I am travelling with a herd of my companion mammals over an area of dry, parched earth.  Yet my eyes and visual cortex are able to discern a distant spot of green and brown as a concentration of things known as plants.  The brain, commanding the eyes to look more closely, enables the visual cortex to spy that this is a rich and dense collection of vegetation.  And the brain’s memory yields up a “conclusion” that other dense collections of vegetation have proved to be a source for water.  Even without the benefit of language that can name things, my mammalian brain has recorded (learned) the causal meaning of an oasis.

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Nature’s Brains, Part 2

July 8, 2012

Bob Fiske

Nature’s Brains, Part 2

(Note: I invite you to read Part 1 before you dive into this part.)

Nature is the Great Inventor.  Through its innovative experiments we have an awe-inspiring array of species.  Considering only the animal kingdom, there exists such a marvelous set of unexpected forms.  Some, in fact, are altogether strange.  Nature makes even the most creative Hollywood creature-maker look like an imbecile.

Among nature’s animals on this planet (both living and extinct), there is a notable subclass, namely, those creatures possessing a brain.  Now, at the extreme, where we find insects, spiders, bugs, worm and snails, we might want to argue about what is the minimum level of neural tissue that actually qualifies as a brain.  But that is not the motivating question behind this essay.  So we will keep our focus on animals whose possession of a brain is undeniable.

Over the eons nature rolled many dice, so to speak, and out popped numerous experimental forms.  Many of these species couldn’t cut it.  Either these species failed to compete or to harmonize with other species in their neighborhoods and petered out.  More likely it was not an either-or.  These extinguished germ lines most likely failed to compete and to harmonize with other species.  More about that, later.

However, somewhere in the succession of new forms, one innovation appeared that had lasting value: a brain.  In order to continue this discussion, we must relieve ourselves of the conviction that human brains are the only ones worth considering.  Or even that only mammalian brains merit discussion.  Certainly there are many scientists—biologists, ethologists, geneticists, neurologists and bio-psychologists—for whom this widening of the field is a no-brainer.  (I just made a funny.  Huh.)

But to include the rest of us in on the discussion, let’s start by noticing that once nature chanced upon the brain as an animal trait, it was simply too valuable to relinquish.  Animals with brains prospered, and the number of such species multiplied.  Brains can be used in creatures that graze, hunt, swim, fly and burrow.

There is a little more to the story, though.  Brains come at a cost.  They must be encased for protection.  They put demands on their owners for large amounts of oxygen, chemical energy (glucose), and other nutrients.  As an organ, brains take longer to develop than other organs.  Some animal experiments probably abandoned the concept (“It’s a luxury, not a requirement”) and chose a different reproductive strategy, such as laying a million eggs.  But, seeing how many brains inhabit the directory of animals, I think we’re safe in concluding that brains established themselves in the genetic menu because of their lasting value.  (Kind of like pizza and ice cream.  I’m only kidding.)

Well, then, what exactly is a brain, one might ask?  In questions of this sort, I usually start with the simplest definition I can imagine.  A brain is a storage medium that can encode (store) a repertoire of behaviors and can allow the animal to apply them in the appropriate situations.  With a brain, an animal can either store more types of behaviors and/or more complex behaviors.

As an aside, one of my favorite examples is the web-building spider.  The spider web is a marvel of engineering.  The spider can build one wherever it finds itself, using whatever objects happen to be present.  If you look at many garden spiders in the city, you will find that they opportunistically choose a spot for a web because there is a nearby light that will attract flying insects.  Even a streetlight three houses away will do.  They don’t stop and check to see if there are precisely six branches and an overhang.  They go ahead and use the available props.  This is the height of creativity!

In spiders I see a tiny brain used to store one fairly complex behavior (web-building) and an assortment of quite simple ones (such as running for cover if a shadow moves over quickly).

So, just like the cellular telephone, brains found a stable niche because they proved to be a useful “natural technology” that was too valuable to give up.  As a result, there ensued a lengthy series of design experiments to show what could be made from this basic concept.

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Nature’s Brains, Part 1

July 8, 2012

Bob Fiske

Nature’s Brains, Part 1

 "But the old crow comforted me, saying, 'If you only had brains in your head you would be as good a man as any of them, and a better man than some of them.  Brains are the only things worth having in this world, no matter whether one is a crow or a man.'  After the crows had gone I thought this over and decided I would try hard to get some brains."
     -- The Scarecrow in: L. Frank Baum, The Wonderful Wizard of Oz, 1900

I have a little story to tell.  I went on a walk in the neighborhood I grew up in on a sunny morning in July, 2012.  This is a section of Los Angeles that is a little hilly.  Most of the houses have foundations that are above street level.  All of the streets curve both up and down and to the side.

I came around a curve and caught sight of a clear plastic bird feeder mounted on the outside of one house’s large living room window.  It was shaped like a little house with an opening in front and a sunken floor for holding the bird seed.  Its unusual position—in the middle of a large plate glass window—was what probably attracted my attention initially, but it took only a fraction of a second to notice the little, brown sparrow inside of it.  Standing sideways to my vantage point it leaned forward and down to peck at the supply of seeds.

I stopped, and so did the sparrow.  I did not want to disturb the bird, I wanted to watch it eat.  But the sparrow stood (sideways to my view) and waited.  It waited for me to walk by and away.  I did not.

This little bird stopped its eating because a large animal—a human being—came into view.  The large animal was close enough to pose a potential threat, and so the bird shifted to defensive behavior.

"Close enough".  That is noteworthy.  The house sat on a rise behind a retaining wall.  I was perhaps 15 feet from the front of the house.  Moreover, the base of the house was at least five feet above my eye level.  And the plastic bird feeder in the middle of the window was an additional eight feet above that.  So that little bird sat on a perch 18 feet above the ground on which I stood and 15 feet away.  Or (thanks to the Pythagorean theorem) there were a good 23 feet between my perch and the bird’s.

And, yet, that sparrow registered me as a threat.

Of greater interest to me was how the bird reacted to this threat.  It watched me.  Remember, a sparrow’s eyes are on the sides of its head.  This is generally true for prey animals.  So, standing sideways, it had a direct view of me.  It made tiny little movements up, down and side-to-side with its head.  This is an understandable response to threat.  Not only was it watching me, but it was scanning the environment, the better to assess if there might be other threats.  The better to assess possible escape routes.

I imagine that this sequence of behaviors—feed, detect, assess, and prepare for lifesaving flight—is a normal affair for a foraging, prey animal such as a sparrow.  Its brain is wired with strategies for preserving its existence.  More about that later.  Yet, I wanted to see if I could maintain a non-threatening status long enough that the bird would relax its threat response and return to eating.  So, I stopped.  I stood still.

I stood motionless, and the sparrow scanned with its little head movements.  I am a patient person.  I waited.  After nearly a minute the bird made a little forward-bobbing movement with its beak.  Just a little movement.  It wanted to return to eating.  But the parts of its brain responsible for the defensive scanning and preparation for flight overrode that impulse.

These impulses, feed, detect, assess and prepare for flight, seem to have independent existences in the brain.  Like a committee formed of department managers, they must come together and negotiate.  Who is going to dominate?  Who will take control of the bird’s behavior?  That all depends on the current conditions, of course.  If a potential threat appears, then the defensive managers win the negotiation.  If the threat fails to materialize, then the feeding manager garners more power in the negotiation.

I could see these internal negotiations taking place—from something as insignificant as a tiny forward-bobbing motion of the head.  I knew that I could affect the outcome of the negotiation simply by continuing to wait without moving.

Another 15 or 20 seconds.  Did I see another forward head movement?  Perhaps.  Now it was well over a minute since our encounter had begun.  There, definitely.  A forward head movement, followed by more scanning.  Another quarter of a minute.  A forward movement, this time more pronounced.  Not the actual eating of the bird seed on the feeder’s floor, but a clear indication that the impulse to feed had not been completely suppressed.

And so it went.  I believe that it was coming up on two minutes.  Finally I saw a deep bowing of the head.  The bird’s beak appeared to make contact with the seed.  Nervously the sparrow resumed its eye-scanning.  Then it tapped its beak back to the bird seed.  After a short pause it did that again.  And again.

I was rewarded by my frozen stance.  As I expected, I could outwait the nervous behavior produced by the little sparrow’s marvelous little brain.

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Happy Birthday Independence Day

July 4, 2012, Bob Fiske

Happy Birthday Independence Day

Happy Birthday AEAD.

It is July Fourth.

Your combined ages is 167 years.

I hope you are well.

I hope your spirit is lifted.

I hope your spirit knows it’s lifted.

I hope you know how to lift your spirit.

I hope your path is the journey of a lifted spirit lifting spirits.

May you also experience peace and compassion.

May you and all living beings find connectedness and compassion in the path ahead.

As I seem to see what lies on the path ahead I know that calmness could be our greatest virtue.

As we awaken to what we have created, with a calm spirit we could fully open our eyes and our minds.

From clear, calm seeing we could begin to accept the truth of what we have done and grasp it without blame or remorse.

As friends we could begin to fully accept the state of the world and the state of ourselves.

With a calm regard we could begin to accept the pain of knowing and, from that, the peaceful release of responsibility.

As companions on our one ship earth we could know each other warmly.

We could reside quietly as though in the restful time of the setting sun.

We could be ourselves newly and be aware that, in the new dawning, petty disputes and trivial concerns could be put aside.

We could accept the role of doing the greater work of serving the harmonious welfare of all that is impermanent.

We could understand that we are imperfect knowers of Good and embrace our limitations even while we strive to reflect It into the world.

We could identify our inner selves, experiencing that this is who we were all along.

We could realize that the struggle to be our authentic selves was bound to lead us to this place.

And this place could allow us to live as ourselves, in the deepest sense possible.