Farther down the bar, your mom will also pick your name out of the noise, even though she’s nursing a scotch and soda and talking politics to the bartender who is praying that you’ll order so she can ignore this crazy woman.
Have you eaten lately? Because a waiter carrying a steaming plate of chicken fajitas just passed behind you. You’re not paying attention though, right? Well, if you’re hungry, your inner puppy just barked and is about ready to dance for your supper. How did you dig the smell of fajitas out of the smells of generations of spilled beer, the tequila the guy to your left is about to knock back, and your own sweaty shirt?
In all that sensory noise, how can you hear your name and lust for those fajitas when your intent is to catch the bartender’s attention and ask for a nice, hoppy ale?
The vast majority of our thoughts are unconscious ones.
Are you really only paying attention to the beer taps? Of course not. Your senses are firing up networks all over the place and trying to associate every input with every other input, as well as every memory you’ve ever recorded. Your head is a busy place.
A picture emerges of separate parts of your brain going about their business. At the lowest level, each sense has dedicated processors that reconstruct their own inputs. At each stage of reconstruction, the networks of neurons that perform the low-level reconstruction forward their results to the layers above. Since these low-level, bottom-up processors perform isolated rote tasks without a whole lot of attention to or from other processes, and since there are lots of them, I call them dumb parallel processors: parallel because they work alongside, but pretty much independent of, each other, and dumb because I don’t respect them as much as I should.
Consider your mother. Your eyes catch light and transmit raw data along the million axons of your optic nerve. Since they’re carrying electrical signals, thinking of them as wires isn’t too far off the mark. One leg of information goes to your thalamus, part of your inner puppy; the rest goes to your primary visual cortex.
The first processing network discerns contrasts and boundaries and produces crude, cartoonish images from the huge set of light-dark intensity and colors transmitted from your retinas. Those crude images are fed to the next layer, as well as the layer above that (let’s call them V2 and V3), and all the way up the visual-processing food chain. As V2 sets about filling in the details of the cartoonish image, V3 compares that crude V1 image to the vast store of images stashed away in your cranium.
Since you’re looking at the beer taps, the only light your eyes are receiving from this woman is from the periphery. That light comes from saccades, the constant flitting about of your eyeballs. The illusion that you see an entire scene when you really only look at details one at a time serves as an outstanding example of the amount of processing between your experience and reality itself. You’re not even looking in your mother’s direction—at least not yet.
V3 provides whatever similar images it finds in your memory to V2. V2 uses your experience hanging around in bars to identify both what you’re looking at and everything in your field of view that you’re not paying attention to. Included in that morass of images is a female human. Meanwhile, higher up the food chain, processors offer the crude images from lower processors far and wide for association with other senses and memories of similar experiences.
At the same time that V1, the lowest processor on the totem pole, passes the crude images up the hierarchy, your audio processors perform a cursory analysis to distinguish sounds from the TVs, glasses clinking together, pointless chatter, rhetorical questions, laughter, sighs, and belches. An important detail to keep in mind is that you know you’re in a bar. Stuff that you expect to see in a bar is likely to be ignored unless, as with the fajitas, your processors are on alert to elevate them for wider association.
When V2 finishes tidying up the image, it sends its results back down to V1, as well as farther up. Back at V1, the tidier image is used to more accurately and quickly process the still-incoming visual data. Your brain takes shortcuts at every opportunity, which is usually okay, because it also double-checks everything for consistency and context.
V3 combs through the results from V1 and V2 to identify the people around you to the extent that it can. If you’re attracted to women and feeling a bit lusty, your higher-level visual processor will stash images and locations of women for further consideration—one of which will generate all-too-conscious embarrassment as soon as all the results arrive, in about another half second.
The processing performed in the visual cortices of your right and left brains differs, though there is redundancy. For the most part, your left brain focuses on your hunt for the ideal beer, and your right brain keeps a lookout for trouble, but they talk to each other. Your right brain wants to elevate some of the faces to threat level, and your left brain inhibits those efforts. Your left brain wants all resources tuned into that one tap, but the right brain overrides it when it sees another set of taps at the other end of the bar, one of which has both the letters “IPA” and the image of a floppy-eared dog.
But then, holy shit! Your bottom-up processors raise a flag that your top-down processors can’t ignore. There’s a woman to your right wearing your mother’s perfume.
3.2.2 Your brilliant, top-down, serial, conscious thinkers
At the holy-shit instant, this huge network of unconscious thoughts boils this one association up to your forebrain, insula, and medial prefrontal cortex where it becomes a conscious thought, an experience.
Let’s stop here for a second. I said that the unconscious thought boils up to consciousness. The boiling metaphor is so accurate that I’m tempted to say something stupid like “it literally boils up.” This temptation comes from my suspicion that the transformation from unconscious to conscious follows the physics of percolation—one of the amazing things about physics is how often the mathematical description for one process can be leveraged to explain something that seems completely different.
Old coffeemakers used percolation to brew coffee. A tall pot filled about halfway with water sits over a flame. The flame heats the water to boiling and the boiling action pushes water up a tube. At the top of the tube, the water is deflected by the lid of the pot into a little basket holding coffee grinds. The hot water filters through the grinds, drips back into the pot, rejoins the rest of the water, boils back up, and so on, producing a rather thick, bitter pot of coffee. The lid of coffee percolators includes a clear glass tip so you can see the color of the brew as it percolates.
Here’s the metaphor. Each drop of water in the pot is a thought. At any instant, the whole pot can be boiling, but only one drop of water at a time percolates up to the top and drips down through consciousness. Some of those drops stay in the basket of consciousness grinds, but most of them filter their way through and drip back down to the unconscious parallel processors.
The emergence of a thought into the consciousness grinds creates consciousness itself. We’ll fill out this idea later, but first, you need to dump the half-processed image of your mother from your list of attractive women and curse your inner Freud. Then, if you’re a good son or daughter, call the bartender over and buy your dear mother a drink. And, as long as you have the bartender’s attention, get yourself a beer. You’ll need it to wash down your Oedipus complex.
Figure 9: The percolator metaphor.
In this horrifying example, notice the trajectory of your conscious thoughts. You go into a bar, you ponder the perfect beer, you’re surprised to see your mother, and you buy her a drink, surprising her just as much as she surprised you. Of all the processing in your brain, you were conscious of just a tiny fraction.
You were certainly aware that you bought your mom a drink. That was a top-down process; you directed it by choice. Whether or not that choice resulted from free will is a dicey question that we’ll deflect until later.
Other than the obvious fact that you’re not conscious of them, how do we know that our brains have processing
centers that aren’t part of our wide-awake existence? Scads of data back up the idea. Here are two examples: Blind sight is caused by injuries to V1, the bottom-level image processor. People with blind sight are not conscious of vision. You might think that they can’t see, right? They claim to be blind, after all. But if you hold up an apple and ask them what it is and where it is, their inner puppies manage to convey the what and where. They can’t see it, but they know where and what it is.
Here’s another example: People who have brain injuries in the region where the inner Feynman processes sound into melodies, an ailment called agnosia, are incapable of detecting the melody itself, but they know, by virtue of their inner puppies, whether those melodies sound happy or sad.
The only way we can manage all the data that’s constantly clobbering our senses is to have lots of processors going about their business without conscious attention.
3.3 WE ARE PATTERN-RECOGNIZERS AND MODEL-BUILDERS
As we go about our lives, our bottom-up parallel processors constantly look for patterns by comparing our current situation with previous experiences. Images are associated with memories of other images, as well as the constant incoming stream of sounds, scents, and so on. When a pattern is recognized, the situation is consistent with an expectation, such as “here I am in a bar,” and a low-key sense of certainty is generated and fed forward.
Consistency with the incoming data is sufficient for recognition: consistency, not confirmation. Confirmation requires point-by-point comparison of the incoming data with the expectation; consistency is a much looser criterion. Consistency gives fast approximation; confirmation gives slow precision. If the consistent pattern turns out to be wrong, it can always be corrected, but if we took the laborious route to precise confirmation, we’d still be unclear on whether it was a kind little kitty or a saber-toothed tiger as the feline throat belched our final essence.
The process of pattern-recognition permeates the entire thought process. Our brains have evolved to optimize our ability to decipher patterns even when they are buried in noise.
Let’s go back to the bar.
You’re scoping out the taps. A dozen people are talking within a few meters of you, plus the sound from the TVs, and in that cacophony of noises, you pick out the sound of your former neighbor’s voice saying your name. When the bartender turns to you and you ask for the IPA, she nods and pours.
Consider all those voices. Within our socially tuned brains, various voices sound quite different. But in objective reality, human voices are limited by the length and tension of vocal cords, just like the sounds of a guitar are limited by string thickness and tension from the tuning knobs. Since people follow the same essential blueprint, the size and tension of our vocal cords don’t vary much. We can decipher two human voices even when we’ve never met the people—nothing to it—but to a rhinoceros, we all sound the same.
Bars are packed with scents too. While a dog could decipher the smell of week-old vomit, bleach, ancient cigarette smoke, the scents of each person, each drink, and every food on the menu, we can’t even distinguish a fresh fart from well brandy. But the scent of your mother’s perfume fits a well-established pattern in your brain, not just because you’ve smelled it all your life, but because you associate it with a host of feelings.
The cost of being highly tuned pattern-recognizers is that we’re not always right, and sometimes we see patterns that aren’t even there.
If you happen to be dancing and it starts to rain, then someday during a drought you dance again and it rains a second time, well, you might as well buy a lottery ticket.
Superstition is built on our ability to recognize patterns.
Composing a complex whole from a limited set of possible components is more efficient than composing it from a continuum of possible elements. We build colors from the three primitives that the cones in our eyes distinguish: blue, green, and red.
Just as Starla built an ever-more sophisticated experience of a rainbow from light/dark, then color, and so on, we build our catalog of experiences and memories by assembling combinations of perceptions, ideas, and memories from patterns that we already have stashed away.
3.3.1 First impressions
The first time you see something, your left prefrontal cortex reacts in less than 0.13 seconds. The next time you see it, provided that it’s not threatening, you react in 0.4 to 1.0 seconds. In other words, your first impression demands your attention faster than you can hit the brakes. The second time you encounter it, it takes you from three to eight times longer to respond, if you even bother to notice it.
Consider your first love. As you picture that person, that defining moment of your sexuality, you unfold an archetype against which, like it or not, you measure every other attraction. Odds are that person has come to define your “type”—her flowing brown hair, wide forehead, gently curving jaw, delicious blue eyes, delicate lips, and tender smile, if only she would have danced with me when I asked. Ahem. It’s just as well that those first experiences are fraught with imperfection; otherwise, how could anyone else measure up?
The same goes for your first hate, the bully in second grade who brought attention to your giant forehead, tiny body, and overall cartoon-character appearance. That bastard, with his black hair, pasty skin, constantly running nose, and snorting laughter left an impression, didn’t he? The very thought of him still inspires the desire to strike back. You nearly want to search for him on a social network just so you can dress him down now that you’re—whoa. Sorry about that.
Just as we build every color from combinations of the three primitives, when you first meet someone, you build models of them from your archetypes. By combining pieces of archetypes into a model for the new person, we provide a way to immediately judge them as friend or foe, fun or boring, smart or dumb, liberal or conservative, long before we have interacted with them at all.
If nature rewarded justice rather than reproductive proliferation, then maybe we’d weight impressions according to their frequency of occurrence in different situations, their density rather than their intensity. Instead, to survive the second impression, we overweight the first impression. Having survived two, that archetype/pattern becomes ingrained, though, to be sure, first impressions can be replaced by particularly intense later impressions.
3.3.2 Prejudice
We categorize patterns. Rather than store every variation of a circle, we know the pattern: For it is round. The rainbow of light our eyes can detect spans wavelengths from roughly 350 to 750 nanometers; one nanometer is a millionth of a millimeter. Rather than distinguish every wavelength of light from 620 to 660 nanometers, we put them in the same category and call it red. Until a specific need arises to distinguish between two shapes or shades, it is okay to let circles be round and red be red.
The tendency to categorize generates stereotypes. Since we recognize patterns so easily, we get lazy. Sometimes we accept the category, the form, instead of recognizing how things or even people depart from that form. It’s easier to file things into existing cabinets than to build new ones, so sometimes we put our carts before our asses and willfully declare that the pattern comes before the distinction.
Stereotypes are examples of categories that turn out to be misleading far more often than they’re accurate. Everyone stereotypes other people—but stereotyping is always lazy! The problem is that, at least for cave people, quick and dirty categorization provides a huge advantage in recognizing danger with little survival cost in accuracy. For you and me, trying to have civilization together, stereotypes based on gender, ethnic background, or income bracket put us at a disadvantage far more often than they protect us from danger. In pursuit of efficiency, Mother Nature made it easy for us to be bigots. Apparently she didn’t foresee civilization.
3.4 HOW COME NOVELS WORK?
To understand the world and our place in it, such as we do, we combine the patterns we’ve come to recognize into models. Our mouths don’t water at the sight of steak
, chocolate, or beer; they water at our predictions based on past experiences. We don’t interact with the real external world; we interact with our models of that world.
When you read a novel, you assemble the words on the page into your model of the world. You lie on a beach, open a book, start reading, and soon you’re laughing and crying; your heart rate goes up, and you don’t want to put the book down any more than you want to leave a party while engaged in conversation with a friend.
Stories excite within us the very circuits through which we interact with the world. Like any other experience, that interaction alters our models and changes our worldview. As you envision a setting, your visual processing centers activate in a way that is strikingly similar to how they would activate if you were actually there. In other words, novels are virtual reality. When a novelist does a good job portraying a character in a rose garden, you catch a hint of the scent; an act of fictitious injustice makes you feel outrage; a good sex scene perks you right up.
What gives? Novels are just ink on paper; how can they do this to us? It’s because of resonance.
When you push a kid on a swing, the child goes higher with each push. But you have to push at the right times—at the resonant frequency of the swing—to produce that amplifying effect. Try pushing at random times and the kid will jiggle back and forth and glare at you, maybe start crying, and probably ask for another parent, maybe even be emotionally scarred for life.
We resonate with stories because our neurons mirror the experiences of the characters. Neuroscience has a little pile of evidence for special “mirror neurons” that activate when we watch someone perform an act just as they activate when we ourselves perform that act. The same thing happens with emotions and thoughts. When we see someone else experiencing joy, grief, humor, or even the “aha!” instant of discovery, some of our joy, grief, and lightbulb neurons fire in response.
The Left Brain Speaks, the Right Brain Laughs Page 6