The Left Brain Speaks, the Right Brain Laughs Page 4

  But make no mistake about it: A preponderance of experimental evidence indicates that immediate decisions are made in half the time it takes the signal to propagate from your inner puppy to your inner Feynman. You simply cannot be conscious of decisions made in less than half a second. For some reason, probably to ease intellectual digestion of the progression of events and maintain a feeling of continuity, we have evolved the ability to automatically reorder sequences that occur in less than about three-quarters of a second. I can’t speak for the genuine, though dead, Richard Feynman, and would never disparage his fine reputation, but our inner Feynmans, like spouses and corporate executives, seem to require the illusion of control.

  Fortunately, since the saber-toothed tiger operates with similar wetware, your initial response and the cat’s operate on the same timescale, so you have a chance to get away. But once that 0.2 seconds stretches into 0.5 seconds, if the cat hasn’t caught up with you, your inner Feynman needs to come up with a plan.

  Let’s take another look at what has happened so far, this time with the continuous input of data in mind.

  Say you meet the big cat at t = 0 seconds. The light reflected from the tiger excites the rods and cones in your eyes. Data from your rods and cones are transmitted up your optic nerve to your visual processors. Those processors get to work. The first crude rudimentary images—outlines, edges, and boundaries—are compared to images previously stored in your memory. Then your initial bodily reaction and that rudimentary association of the image arrive at your amygdala and, finally, at t = 0.2 seconds, you start running.

  In the time interval from 0.2 to 0.4 seconds, the data input and processing cycle repeat. With more data, the image is almost ready for your inner Feynman to ponder. You are sweating, your heart is racing, you’re scared shitless, and, yes, you’re running like hell. Still more visual, sound, and scent data arrive in your respective processors. Your amygdala refines your physical and emotional responses.

  So far, you’re not even conscious that anything has happened!

  Finally, at t = 0.5 seconds, that feeling of certainty, combined with unbridled fear, prevents you from wasting time pondering the situation. Instead, you start associating the only now emerging refined images, scents, sounds, and physical sensations with the context of where you are, what tools might be at your disposal, and how to deal with cats. That is, at t = 0.5 seconds, you initiate the process of putting the situation into context—even though you’ve been running for 0.3 seconds.

  After almost a full second, your first conscious thought trickles in. By “thought,” I mean that you experience the association of processed sensory data with memory and movement. This association is essentially a prediction of what will happen in the next half second or less. That thought goes to the thalamus where it is sent to the various sections of your brain.

  Different processors feed information to each other and to your arms and legs. All subsequent data, including fresh sensory data and new, more abstract data created by your brain make their way back through the loop. Your frog reacts first, then your puppy, and long after they’ve been able to react, act again, and then again, your inner Feynman finally starts stroking its chin and pondering a plan.

  Figure 5: Your frog, puppy, and Feynman.

  Your edge is that you can use tools. The saber-toothed tiger’s edge is altogether too obvious. Sorry, my money’s on the cat; your Feynman is too slow.

  Okay, let’s stop here.

  What if, when you walked around that corner, you were instead confronted by a wizened old geezer sitting at a table with a chess set challenging you to a game, rather than a saber-toothed tiger?

  As with the cat, your thalamus sends the data off for processing, but now, when your amygdala receives that data, it doesn’t generate fear—unless you’re like me and the thought of losing a game of wits to a venerable codger is too horrifying to consider. Instead of your inner puppy telling your inner frog to crank up its heart rate and run like hell, your amygdala directs your body to slow down and focus your eyes on the board, the geezer’s face, and the time clock. Rather than forwarding an immediate sense of certainty to your forebrain Feynman, it offers mild uncertainty. Rather than a “get the hell out of here,” your amygdala passes the data along with a shrug of its limbic shoulders.

  The decision of whether or not to accept the geezer’s challenge has many influences. With plenty of time to process the situation, your Feynman provides context and evaluation. But that evaluation and context are not cold and calculating because your inner puppy remains piqued, with tail wagging and ears perked. As your Feynman associates learned properties—how chess is played, experience in competition, how much daylight remains, the weather, etc.—it feeds predictions back to the thalamus regarding the possibilities of victory, defeat, and boredom. Those data go back through the same feedback loop for processing by your puppy’s amygdala, which generates bodily responses to the potential glory of victory, agony of defeat, and tedium of boredom. These predictions weighted by your judgment of their probability generate an emotional response that affects your heart rate. Maybe you start chewing a fingernail, maybe you take a seat and move pawn to king-four, or maybe you check your watch and indicate that you need to be somewhere else.

  In any case, the thought processes that generate your reactions result from a massive feedback/feed-forward system that integrates your environment, your body, and your brain. No decision is made without both emotional and physical responses and only those decisions that afford timescales of at least a few seconds include intellectual deliberation.

  2.4.1 Reaction timescales

  Reaction times are limited by the speed that signals propagate from neuron to neuron, sense to brain, frog to puppy to Feynman. Since the speed of a signal propagating along an axon is roughly 100 feet per second (70 mph or 110 km per hour, about a tenth of the speed of sound), decisions made by processors in close proximity occur faster than those requiring coordination of distant processors.

  Figure 6: Timescales for different types of reactions.

  Your inner frog operates in a few hundredths of a second, your puppy in less than a quarter of a second, and your Feynman in no less than half a second. But your Feynman trains your puppy and frog. For instance, when you make a silly mistake—type the wrong key, hit the clutch instead of the brake, or order a Coors Light instead of a beer— your anterior cingulate cortex raises its error flag in less than 0.07 seconds, which is frog speed. Your inner frog knows nothing about keyboards or cars, though even a frog can identify beer.

  The timescale of conscious and unconscious processes shows that many of our decisions are made before we’ve had time to think about them.

  2.4.2 Positive and negative feedback

  Feedback turns out to be kind of a major theme in studying how the brain works, so we should probably give it a little time in the spotlight.

  Think of feedback as feeding previously processed data back into the input of the processor. Your eyes collect a vision and your nose a scent, yielding a processed image of a cold, frothy beer. You respond with a watering mouth that reinforces the frothy image and you ponder the malt-hop balance. Because of the time scale, your frog spins through about fifteen reactions for every three from your puppy and one from your Feynman.

  Figure 7: Feedback.

  Feedback comes in two categories: positive and negative. Positive feedback reinforces and compounds its input and, left unchecked, leads to extreme behavior. Negative feedback suppresses extreme behavior. Positive feedback amplifies and negative feedback balances or stabilizes.

  That loud, high-pitched, and annoying sound you hear when someone speaks into a poorly placed microphone is positive feedback. The speaker talks into the microphone. Her amplified voice comes out of the speakers behind her. The sound from the speakers hits the microphone and is amplified again, this secondary sound hits the microphone, is amplified and transmitted into a third version that hits the microphone, is amplified and transmitte
d, and so on; this happens over and over, getting louder and louder even after the person stops talking.

  The easiest fix to audio feedback is to point the speakers away from the microphone.

  As a snowball rolls down a mountain, more snow sticks to it, making it larger and larger until the snowball effect culminates in an avalanche. Positive feedback loops reinforce themselves and go ape when left unchecked.

  On the flip side, negative feedback prevents systems from going crazy. Negative feedback is a balancing, rather than amplifying, impetus. Hot summer days are caused by bright sunshine. The longer the day, the hotter it gets. But then the sun sets and things cool off. The negative feedback of darkness pushes the temperature to a stable point between hot and cold extremes.

  Hunger is negative feedback: You get hungry, you eat, you get less hungry, you stop eating. Beer is positive feedback up to a point. You drink, you feel better, you drink more, you feel still better, you drink still more, and you hurl. Then the next morning you feel sick. Addictions, including addictions to food and alcohol, occur when negative feedback breaks down; this allows the positive feedback of satiation and/or buzz to overwhelm the balance.

  Our all-new oversimplification of a deludable left brain and a watchdog right brain gives us a window onto the delicate balance we need to get through life. Frank Ransom told me that he lived the happiest life ever lived, but he didn’t say it was the easiest. He brushed off those kinds of questions. Maybe his delusions of happiness got him through the manure.

  That critical balance teeters now and then for all of us. Addictions occur when, for many reasons, the right brain watchdog lets its guard down. People with addictive personalities frequently, though not universally, have reduced capacity in the right sides of their frontal lobes that reduces the negative feedback of destructive behavior.

  2.5 THE REALITY INTERFACE

  The funny thing about reality is that you can only get so close to it. Our senses compose an interface between our brains and the universe, a reality interface.

  The axon cables that run from your nose to the center of your brain, from your eyes to the back of your brain, from your tongue to the center, and from your ears to your cochlea, right there already in your brain, and from that spiny, bendable, bone-wrapped cable that runs from your ass bone to your head bone and into your brain provide everything you get in here from out there. The in-here/out-there model sort of resembles Descartes’s dualism but without requiring a metaphysical component.

  Everything we experience and everything we are and ever will be are ultimately derived from sensory input. The genetic code that formed when your father’s sperm penetrated your mother’s egg started its random walk through naturally selected mutations a couple of billion years ago. The recipe that made you resulted from the responses of and decisions made by your ancestors—every one of them, from algae to ape—based on their sensory inputs. And now you create everything— the scent of an orchid, the touch of a lover, the sound of music, and the view of the stars—from electrical signals generated by your own sensory acquisition equipment.

  I find it strange that there are no nerves in our brains. The thing is packed with neurons, axons, dendrites, myelin—all that stuff that nerves are made of—but we can’t feel anything inside our brains. A surgeon can go in and poke around while you’re wide awake, and you won’t feel a thing. How weird would it be if we could feel our own thoughts? Contemplating your goal to become a guitar legend would tickle the space just behind your forehead; envisioning a bird in flight, soaring on thermal breezes above the sea, would make your occipital lobe itch. The medical industry could save a fortune in imaging devices.

  “Well doc, it hurts when I picture her with that guy.”

  “Heartbreak is tough, son.”

  “Seriously, right here in the back of my head, a rip-roaring pain.”

  “Oh. Take an aspirin and write a poem.”

  2.5.1 The inescapably subjective nature of our realities

  Here’s a simple definition of reality: stuff interacting in space. That pretty much covers everything that happens, right? Even daydreaming is stuff, since it’s made of neurons exchanging electrical energy stored in sodium, calcium, and potassium ions that move around in your head.

  Objective reality would account for everything everywhere, but we don’t have access to that. Even with equipment, we’re not even close.

  You only see three colors, two or even one if you’re colorblind, a tiny fraction of the colors that stars radiate. So we build equipment to see light beyond the rainbow’s spectrum, supervisual light like x-rays, and sub-visual light like radio waves. It’s the same deal with sound: You can hear as low as 20 Hertz (Hz) and feel lower frequencies if they’re loud enough—the steady beating of bass lines blasted from tricked-out cars—and maybe as high as 20,000 Hz, far from what dolphins and bats hear, 150,000 and 200,000 Hz respectively. One Hz is a cycle per second, about the rate of your heartbeat. Envision how a strummed guitar string oscillates back and forth. The number of oscillations per second is the frequency in Hz.

  Since the universe doesn’t really exist the way you experience it, there’s a huge gap between absolute reality and your perceived, subjective reality.

  What’s more, since our senses are not identical, the raw data we each use to create our realities differ, and we each create different realities. Maybe I’ve been to louder concerts and lost a bit of hearing; perhaps your sense of smell wasn’t trashed by smoking various substances in your well-spent youth; maybe you didn’t suffer from migraine headaches that trained you to avert your eyes from bright lights.

  The contexts of our perceived realities also differ because our experiences differ. Where you might hear pleasant, creative music, I might wonder why someone would blow a horn when she could thrash a Stratocaster?

  Our realities are continuous chains of perceptions. By perception, I mean the association of stimulus and thought. For reality to make sense, we need context. To create context, we associate our current perceptions with what we’ve experienced in the past and our expectations for the immediate future, and then we squeeze the present right into the gap in a way that makes sense. Since we have different experiences and expectations, what makes sense to you isn’t likely to make sense to me. Listen carefully the next time you talk to someone. The two of you will talk about the same subjects, but if you listen closely, I bet you’ll notice that you’re not having exactly the same conversation, not quite talking about identical ideas and phenomena.

  If you were plopped into whatever situation you now find yourself—at the same age and with the same physical body and brain but with no experience, no previous thoughts whatsoever, no language skills, no learned abilities—nothing would make sense. You’d be worse than lost; you couldn’t even claim to exist! You couldn’t claim anything.

  Since our perceived realities are derived from thoroughly processed sensory input, all reality is virtual. Einstein nailed it when he said, “Reality is merely an illusion, albeit a very persistent one.”

  2.5.2 The realities of whales, dogs, and trees (and naked people)

  To get an idea of how our differences affect our perceptions of reality, let’s take a look at the perceived reality of an animal whose senses are tuned for a completely different environment.

  Sperm whales are the largest predators on earth and have the largest brains of any animal, about six times the size of a human’s. We share the same five senses but use them in different ways.

  Whales have huge eyes but don’t use them for the bulk of their visualizing. It’s murky underwater. At the depths where sperm whales like to hunt, almost two miles deep, a mammalian eye isn’t of much use. To see, whales, dolphins, and porpoises emit tightly directed sounds. When these sounds hit something, they echo back. From the timing of all the echoes, whales construct three-dimensional images including shape and location.

  We see by looking around and gathering the ambient light reflected from things, but when a whal
e looks at something, it projects bursts of sound in specific, considered directions and then assembles images from the reflections.

  The differences in visualization techniques result in big changes in perception. First, the length of time it takes from the emission of the sound to detection of the echo indicates the distance between a whale and an object. From less than about 15 feet (5 m), people use parallax—the variation between what they see in their left and right eyes—to gauge distance. At larger separations, we use scale combined with experience. If someone looks really small, you figure that they are proportionally farther away. Whales determine distance by the time interval between when they transmit their sonar sounds and when they hear the echoes; the farther away, the more accurate their measurements, the opposite of humans.

  Whales “see” how fast something moves and whether it’s coming toward or going away from them because the sound frequency shifts. If a fish swims toward a whale, then the reflected sound has a slightly higher pitch, just as the sound of a car approaching has a higher pitch than when it’s departing—the Doppler effect. Since specific pigments don’t alter the way that sound reflects from an object, whales don’t see colors. Instead, they “see” how rigid something is. Since steel reflects sound with a sharp, high-frequency response and mud and kelp are more absorptive, whales “see” hardness, fragility, and malleability. They would never believe a big boulder-shaped piece of Styrofoam was actually granite.

  Seeing by directing sound at things is like using a flashlight in the dark. In a well-lit room, you can look at me and I won’t know you’re looking unless I catch you. In a dark room, if you flash a light at me, I know you’re looking. In whale society, everyone knows where everyone is looking all the time. Just as we can recognize each other’s voices in a crowd, whales recognize each other’s gaze. No peeking allowed! Plus, sonar can penetrate skin. If a female whale is pregnant, everyone knows. If someone has a tumor, it’s the talk of the pod.