Who are we? Don't ask our neurons, they're a bunch of idiots. And don't answer with your gut, because your gut isn't even human.

As the philosopher Daniel Dennett likes to remind us, each one of us is made up of trillions and trillions of living organisms (we call them 'cells'), and not a single one of these living things that make us up has any idea who we are, or even cares.

Take a moment to let that sink in.

Now, don't blame the cells for not caring; they are all living organisms and thus have their own metabolism, their own respiration, and their own reproduction to manage.  They don't have the time to worry about the bigger picture.  Nor do they have the mental capacity.  Even neurons--the living organisms that do our thinking for us--are quite dumb, when considered on an individual level.  Even though it is our neurons that allow us to think and learn, no individual neuron can think or learn.  Each one follows very simple rules of behavior: basically if a certain number of its neighbors are firing, they fire too.  That's it.  And yet somehow, out of all those mindless firings of neurons, a mind emerges--a mind that can even write a blog post about the neurons mindlessly making a mind.

Three stupid neurons.

More than human.
It gets even weirder.  A good proportion of the cells that make us up aren't even human!  Before I tell you what percentage, I invite you to take a guess: What percentage of the cells in our body are human cells?  90%? 70%? 50%?  So far, you're way off.  (Are your neurons even firing correctly?  Sheesh.)  Truth is, human cells are the in the minority amongst humans, by a long shot.

Human cells comprise only about 10% of the 100 trillion cells in a human.  10%.  The rest of the cells in our body are mostly bacteria, which generally take up residence in our gut.  Far from being invasive, our bacterial friends are an integral part of our digestive system, breaking down food and passing along the energy and vitamins to us after they're done with them.

Are you the same "you" that you were 10 years ago?
Biologically speaking, not exactly.  The living organisms that make us up generally do not live long enough to see us grow old.  Our body may grown and develop at a steady, slow pace, but that is due to a complex flux of cells dying and new cells being born to take their place (here's a nice NYT article on this).  The skin that covers your entire body--the thing that makes you look like "you" with your dimples and wrinkles and all--is not even the same skin you had two weeks ago.  The stable patterns in our skin, including our fingerprints and dimples and wrinkles and all, are sort of like traffic jams that persist even after all individual the cars that started the jam travel on down the road.

Down another level, they say that most of the atoms and molecules that make up the cells are replaced by other atoms (of the same variety) every year or so.  Since the new atoms are functionally equivalent to the old atoms, we would never know the difference.

So what are we to make of this?
So, if the neurons that make us think are all stupid, and the cells that make us up are dying all the time, how do we think?  How do we persist?

Part of what makes this all so mysterious is that we are so far removed from the microscopic level of the goings-on of our body that we have no sense of how the micro-level goings-on give rise to the macro-patterns of our daily life.  But there are some systems in nature where the levels are not so far removed, and so we can learn something about this mystery by studying them.  I will briefly introduce you to two of them: slime molds, and ant colonies.

Slime molds
The slime mold may be one of the grossest organisms on earth, but it is also one of the most fascinating.  We humans like to think of our life cycle in terms of our whole body, not our cells, but the life cycle of the slime mold doesn't work like that.

The slime mold spends much of its life as a single-celled organism, not unlike an amoeba, generally sliming around.  But there comes a point in the life cycle where tens of thousands of individual cells come together and act like one big organism.  First this aggregate organism looks like a slug, slithering around, eating, sliming, and doing whatever it is slugs like to do.  Then during it's reproductive stage the slime mold self-organizes into a mushroom-like stalk, releasing new spores into the surrounding environment and starting the whole process over again.

Although individual slime mold cells are just about as dumb as our individual neurons, the aggregate of slime mold cells can be pretty darned smart.  For example, they can find their way through a complicated maze to get to food:

Ant colonies
Although ants may be smarter than slime mold cells, they are still pretty dumb.  What I mean by that is that ants follow a very simple algorithm for guiding their behavior, a very simple decision-making procedure based entirely on pheromones.

If, in their walking around, an ant happens to cross paths with another ant, they give each other an antennae high-five and sniff out the pheromones.  There is a pheromone that signal one of a few basic meanings: "I found food" and one for "I'm working on the hive" and another for "there's a threat to the colony".  If they sniff the pheromone for "I found food", then they head in the direction that ant was coming from, repeating the process with other ants, until it ultimately finds the food.  This is not much different than our dumb neurons' algorithm of "if my neighbors are firing, I will too".

Now, despite being made up of dumb ants, an ant colony is pretty darned smart.  For instance, they can solve the complicated problem of allocating the optimal number of ants to various food sources at various distances with varying amounts of food.  (here's a nice TED talk on the emergent intelligence of ant colonies)


Also, ant colonies persist for decades, even though the individual ants generally die after several months or at most a few years.  (The queen is the exception to this rule, she's around for up to 21 years).

So, ant colonies and slime molds each give us insight on how a form of intelligence can emerge from the collective behavior of dumb individuals, much like mindless neurons can collectively make a mind. They also lend insight onto the persistence problem, how we can be around for decades when most of our cells are long dead by then.

The bigger picture.
Now that we've seen there's no real magic to how we can be composed out of a bunch of dumb organisms but still be relatively smart, there are more questions to consider.  Should we feel bad if we scratch our cheek and kill thousands if not millions of living organisms?  Is it possible that individual humans could be part of some larger system that is even smarter than any individual humans?  If so, should that system feel bad if it happens to "scratch it's cheek" and wipe out thousands if not millions of humans?  And what should we call that system?  I propose that we call this hypothetical system "Frank."  Frank, if you're listening, please don't scratch your cheek!!!


Extra goodies:

• this article also reports on a finding that human cells even forage for food in a pattern similar to other scavengers, including sharks and um, penguins
• another video of slime mold finding the shortest path to food through a maze 
• here's a research article on the how ant colonies solve complicated problems with dumb ants

Do you have the time? Some surprising facts about how consciousness works

Surprising fact: The neural signals from a drummer's foot take almost of a third of a second longer than do the signals from the hand when they are playing the same beat.

That's not all.  Whenever you stub your toe, there are pain signals that get to the brain almost a third of a second slower than the others, even though they contribute to the very same pain sensation.

How does the brain work this out to end up with one conscious experience of pain, or of a funky drum beat?  Does the brain wait for the last signal to come in before it puts it all together into a feeling?  Or can it revise and resubmit sensory information to the running journal of conscious experience?

An illusion called 'the phi illusion' helps to further illustrate the problem, and how the brain works it out. The result is really quite crazy.

The Phi Illusion

The phi illusion is the reason why we can watch movies and see them as motion rather than as a sequence of still pictures, which is all a movie really is.

For example, here is the first movie ever made: 1st movie ever.  In 1878 Eadweard Muybridge filmed it by lining a stretch of track 12 cameras that went off as a horse ran by.  When we experience the horse's continuous motion means that we are, in a sense, filling in the blanks between pictures.

The illusion is hard to appreciate, because we are so familiar with motion pictures.  But a way to notice the illusion more clearly is to focus on one or two features changing between frames.  Here is an animation of a dot that looks like it's moving back and forth while changing colors, at least for certain settings of the framerate.  But really, it's just two dots, one red and one green, flashing on and off with just the right delay between dots.

When you experience that dot moving back and forth, it seems you must been extrapolationg, somehow, where the dot was between frames of the animation.  And what color it was.  But just what color was it?  And where exactly did you "see" it in between frames?  Are those things somehow registered somewhere in your brain as sensory information?  Or are you just telling yourself a story about what happened and the details are left ambiguous and unexamined by your consciousness?  According to the philosopher and cognitive scientist Daniel Dennett, conscious experience is more like a story you tell yourself about what happened.  There is no "halfway dot" registered anywhere in your visual cortex.

Daniel Dennett has explained this illusion with his "multiple drafts" model of consciousness.  This theory says that we are always making up narratives of "what's going on".  There are usually more than one versions of the story floating around, and its never too late to revise...your consciousness experience is what emerges from an evolutionary-like battle between ideas of what happened.  In the phi illusion, stories that involve motion get selected for so that they end up in the later "drafts" of the story.

The dot appears to move back and forth because when it goes from say, being a red dot on the left to being a red dot on the right, because once that red dot appears we revise the story to include motion, and a color change.

So when a drummer plays a funky beat, he does not have to wait for all the neurons to reach his brain to from his foot as it hits the kick drum before he truly experiences the beat.  And the beat is not experienced as "smeared out" in time, either.  This is despite the fact that multiple kinds of neural signals contribute to the same sensation, some that arrive up to a third of a second later.  Once those straggling neurons deliver their message, the drummer's conscious experience of "the beat" is revised accordingly.


You may have experienced for yourself how the experience of the past can be "retrospectively presented" to the present version of consciousness, say, when you suddenly notice a church bell has been ringing and you are still able to count the chimes, even though you didn't notice it when it started ringing.  You just submitted a new draft that includes revised information about the past.  The versions of your story of consciousness that did not contain bells ringing got beat out by versions that included bells ringing, even though the battle took some time.

Okay, that's all I have time to write.  Or at least that's what I'm telling myself.

Here are some more links for the phi illusion, and related illusions:

• http://www.philosophy.uncc.edu/faculty/phi/Phi_Color2.html
• http://www1.psych.purdue.edu/Magniphi/SimpliPhi.html
• http://highered.mcgraw-hill.com/sites/0070579431/student_view0/chapter8/phi_phenomenon_activity.html
• http://www.lifesci.sussex.ac.uk/home/George_Mather/TwoStrokeFlash.htm
• picture-a-day for 3.5 years

What’s really happening

A story about stories

There is a fundamental paradox that we are all vaguely aware of, even if we haven’t quite articulated it to ourselves.  Unlike the paradoxes of physics and philosophy, which we may never personally encounter, this paradox resides right under our noses.  More specifically, it resides right at the tip of our tongue.  It also buzzes incessantly right between our ears, being the fabric out of which even our internal monologue is woven.    It is the paradox of storytelling—the holy trinity of the story, its teller, and its audience. 

When I say storytelling you probably think of the sorts of storytelling done by professionals such as Twain or Poe, or the kind that is performed to a group sitting around a campfire or a dinner table.  And I do mean those; but I don’t mean only those.  I mean storytelling as grand as telling the story of our cosmic origins, or as minute as silently but persistently telling ourselves what it is we are thinking about at the moment…and everything in between.

We are all storytellers.

Historians compose stories about civilization, the ideologies and innovations that compete and collaborate to form periods of stability, progress, and revolution.

The press and its journalists compose stories that amount to the history of “now”—events at the intersection of people, their roles, and the motivations that drive them to act according to their roles.

Biologists tell same sorts of stories as historians and journalists; the differences amount to ones of scope, with roles played by very different sorts of characters, the innovations of a much less teleological nature, and the motivations largely being those of survival.  But really these are not such dramatic differences after all.

Physicists tell causal stories about particles and their interactions.

Your mind tells stories about you, what you’re doing, what you have done, and what you plan to do.

How many stories are there?

We like to think of history as a continuous stream of goings-on.  So much so that we each tend to decide on one story and stick with it, quickly forgetting, ignoring or even deleting versions that don’t jive with it.  We all know it’s the winners that write the history books; this is true of the shared history written down in books as well as our personal histories written down in our stream of consciousness.  But if you’re really observant, you can sometimes spot multiple drafts of the same story before one get chosen and the other swept under the carpet. 

Case in point: the recent protests in Iran (video).  There are two major versions of the same events.  I’d like you to suspend judgment, if just for a moment, which version you believe.  (btw I’m going off this NY Times article)

Version #1: The Iranian government says that western countries helped orchestrated the protests, and that shots from the crowd struck and killed several people, including Ali Mousavi, the nephew of the opposition leader.

Version #2: The people in the street says that the protests were peaceful, but that revolutionary guard soldiers violated the rules of the holy day by shooting into the crowd, possibly even assassinating the nephew of the opposition leader.

These two versions of the story seem completely incompatible.  How can one person ever believe both at the same time?  How can it be decided which version is a “factual” account of the events?  Most likely what will happen is that one group of people will believe one version, and another will believe the other.  Whichever story gets believed by more people in the end will survive and become the “official” account, the other will pretty much die away.

What’s the real story, and who gets to tell it?

And now for the paradox. 

We all know that there are many sides to a story.  And so it makes sense to say that there is no one real story of what really happened.  There are only versions of stories, which are unavoidably colored by who is telling them and who they are being told to. 

But on the other hand, to say that there is no privileged version of what really happened—there is no plain and simple truth, no bare fact of the matter—seems totally crazy. 

I think this paradox, just like any paradox worth its mettle, is inherently unresolvable.  But that does not make it a dead end.  Keeping this paradox in mind helps us remember that we may always be wrong about even the things we’re most certain of.  I think this is a crucial step—perhaps THE crucial step—towards the peaceful resolution of conflict.