Synopsis
A groundbreaking investigation of the brain’s hidden logic behind our strangest behaviors, and of how conscious and unconscious systems interact in order to create our experience and preserve our sense of self.
From bizarre dreams and hallucinations to schizophrenia and multiple personalities, the human brain is responsible for a diverse spectrum of strange thoughts and behaviors. When observed from the outside, these phenomena are often written off as being just “crazy,” but what if they were actually planned and logical?
NeuroLogic explores the brain’s internal system of reasoning, from its unconscious depths to conscious decision making, and illuminates how it explains our most outlandish as well as our most stereotyped behaviors. From sleepwalking murderers, contagious yawning, and the brains of sports fans to false memories, subliminal messages, and the secret of ticklishness, Dr. Eliezer Sternberg shows that there are patterns to the way the brain interprets the world—–patterns that fit the brain’s unique logic. Unraveling these patterns and the various ways they can be disturbed will not only alter our view of mental illness and supernatural experience, but will also shed light on the hidden parts of ourselves.
(With black-and-white illustrations throughout.)
Extrait
Introduction
Our Unconscious Logic
Walter had been acting strangely. When friends or family visited, he ignored them unless they spoke directly to him. Until they uttered a sound, it was as if they weren’t even there. While walking around his living room, Walter stepped right into his coffee table, then into the wall. He missed widely when reaching for a cup of coffee and knocked over a vase instead. At age fifty-five, Walter was having problems with his vision, yet, inexplicably, he said there was nothing wrong with his eyesight. But why, Walter’s family wondered, would he deny it? Why wouldn’t he seek out help? Confused, they pressed him to go see a neurologist. Walter reluctantly agreed. When he arrived, Walter had the following exchange with his doctor:
NEUROLOGIST: How are you?
WALTER: Fine.
NEUROLOGIST: Anything wrong with you?
WALTER: No. Everything’s perfect.
NEUROLOGIST: Anything wrong with your vision?
WALTER: No. Works fine.
NEUROLOGIST (showing a pen): Then can you tell me what this is?
WALTER: Doc, it’s so dark here; nobody can see anything.
With daylight streaming in through the window, the room was plenty bright. Nevertheless, the doctor humored him.
NEUROLOGIST: I put the light on. Can you now see what I have here?
WALTER: Look, I don’t want to play games with you.
NEUROLOGIST: Fair enough. But can you describe how I look?
WALTER: Sure. You are a small, fat chap.
The doctor, who was actually tall and thin, understood that Walter wasn’t simply denying that he was blind. He actually didn’t realize it. Was he delirious? Was it early Alzheimer’s? Perhaps he needed to speak with a psychiatrist.
The neurologist could infer that there was a connection between Walter’s loss of sight and his delusion that everything was fine. Behavioral tests, however, would not be able to identify that connection. He would have to peer inside Walter’s brain. A CT scan of his head revealed that Walter had suffered a massive stroke, causing damage to both sides of his occipital lobe, which processes vision. That explained the blindness. But the CT showed something else: damage to the left parietal lobe. Among its many functions, the parietal lobe helps interpret sensory signals, especially visual ones. It compiles the basic visual information sent from the occipital lobe and integrates it to help construct a streamlined picture of the world. The parietal lobe is involved in monitoring how the visual system is working. But what if that monitoring function were impaired?
Walter was diagnosed with Anton’s syndrome, a rare disorder in which blind people don’t realize they are blind. Patients with Anton’s syndrome tend to make excuses for their perceptual mistakes, such as “I’m not wearing my glasses” or “There’s a lot of glare from the sun.” As one theory goes, this happens because there is a disconnect between the visual system and the brain regions that monitor it. As a result, the brain never gets the message that there’s a problem with vision. That’s why Walter didn’t realize he was blind.
But this story goes deeper still. Not only did Walter fail to admit his blindness, but he came up with an alternative explanation for his symptoms (“It’s so dark here”). Walter’s brain was faced with a confusing situation. On the one hand, the brain was having trouble perceiving the world. On the other hand, because of the stroke, the brain didn’t know that the visual system had been destroyed. What could explain a loss of sight in a person with an intact visual system? It must be dark in here. Faced with contradicting pieces of information, the brain came up with a story to reconcile them. And it was a pretty good one. You might even say that given the circumstances it was perfectly logical.
Deep within our subconscious, there is a system that quietly processes everything we see, hear, feel, and remember. Our brains are constantly bombarded by innumerable sensations streaming in as we interact with our surroundings. Like a movie editor who collects and organizes all the footage and audio to create meaningful stories, the underlying logical system in the brain assembles all of our thoughts and perceptions into a sensible narrative, a narrative that becomes our life experience and sense of self. This book is about that underlying logic and how it creates our conscious experience, whether in those suffering from the weirdest neurological illnesses or during our simplest day-to-day feelings and decisions.
Our objective will be similar to that of other books in the popular science and psychology domain: Can we discover the underlying reasons for the way we think and act? However, we will take a different approach. Many books you might have encountered on the brain rely on behavioral research that, while enlightening in its own right, often doesn’t look inside the brain to tell us where that behavior comes from. Suppose I give you a machine hidden inside a black box and ask you to figure out how it works. The catch, however, is that I don’t let you see what’s inside. All the gears and pulleys and levers are concealed within the dark encasing. How would you assess what the machine does? Without the ability to examine the underlying mechanics, all you can do is try using the machine in various ways and look for patterns. From there, you can infer how the machine works, but there would still be an element of conjecture. This is a real-world problem in fields like engineering and software development. Consider a software engineer who tries to decipher how a program works without having access to the underlying code. In what is called black box testing, the software designer enters a variety of inputs (such as pushing a button) and records the outputs (seeing what happens) to make educated guesses about how the system works, all without any knowledge of its actual internal structure or mechanics.
That approach is used today to study the human brain. For instance, in a popularized 2010 study, researchers from Harvard, Yale, and MIT had eighty-six volunteer subjects participate in a mock financial negotiation: bargaining down the price of a car with the sticker price of $16,500. One by one, each subject would sit in a chair facing an experimenter who was playing the part of the car salesman. But there was a catch: half the participants were seated in hard, wooden chairs, and the other half were treated to plush, cushioned ones. The result? Those given the hard chairs were the harder bargainers. They were more forceful in their negotiations and bargained the salesman down to a price that was on average $347 lower than that of the comfy chair group. Apparently, the added comfort of the cushioned chairs led the other group to agree to a higher price. Magazines, books, and other commentaries cited the study as yet another breakthrough in the new science of the unconscious. Take, for example, this response from a 2012 article in Ode magazine:
This “hard chair effect” is part of a torrent of new research that is unlocking the mysteries of the human unconscious and showing how its enormous powers can be harnessed . . . Over the past decade, neuroscientists and cognitive psychologists have been gradually decoding this unconscious operating system and can now tap into it to induce everything from cleanliness to cleverness in unwitting subjects.
The study tells me that there’s an association between chair comfort and the force of negotiation, but it doesn’t explain the cause of that interaction. What has been “decoded” here? How does the sensation of hardness affect decision making? What system is at work? What model have we discovered that can be applied and connected to other phenomena?
This study is an instance of black box testing. Just like the software designer, the experimenters never gain access to the underlying “code.” They observe a trend of inputs and outputs, but the crucial workings of the machine that generate that trend remain hidden.
In this book, we will explore questions about human consciousness by cracking open the black box of the brain and peering at its inner workings. In the process, we’ll discover that underlying many of the most mysterious phenomena of human experience, and even the simplest day-to-day decisions, there are distinct neurological circuits, uniting seemingly disconnected facets of our life experience with a single explanation.
The structure of this book is in the form of questions. I have a lot of questions. I am a grown-up version of that kid in the backseat of a minivan who asks his parents a question and then, upon hearing the answer, incessantly responds with “but why?” until he drives them to near insanity. In college, this tendency led me to study the art of asking questions: philosophy. Philosophy teaches us to ask questions with precision, to cut through the surface of an issue until you reach the core principle that explains it in all its aspects. As my education moved on from philosophy to neuroscience, to medicine, and eventually to their overlap in medical neurology, I tried to apply that same rigor to a new set of questions: How does decision making work? How do mental illnesses affect the way we think? How do we interact with our brains, and how do they make us who we are?
Our questions will lead us to the mysteries of perception, habit, learning, memory, language, and the very existence of our selfhood and identity. We’ll touch on everything from alien abductions, detecting fake smiles, and the real story of schizophrenia to sleepwalking murderers, the brains of sports fans, and the secret of ticklishness. We’ll open the black box and, as best we can, use the findings of neuroscience to trace those behaviors to the underlying brain mechanics from which they emerge. With each question we answer, new ones will arise. Every question and answer will build on the previous one as we inch closer to understanding the central questions facing modern neuroscience.
In this book, we will follow the workings of two systems in the brain, the conscious and the unconscious, investigating how they work in parallel and, more important, how they interact in order to create our life experience and preserve our sense of self. My hope is that by the time you finish this book, you’ll see that there are discrete patterns in the way that unconscious mechanisms in the brain guide our behavior. There is an underlying neuro-logic that drives our experience of the world. You might think of it like a piece of software. Our challenge is to decipher that logical system, not only by observing its inputs and outputs, but also by seeking out the brain systems that generate it. Cracking the code of our internal software has far-reaching implications for neurological and psychiatric research, for the study of human relationships and interactions, and for our understanding of ourselves.
So, where do we begin? In briefly mentioning Walter (note that throughout this book, I have changed the names of people I mention in order to protect the identity and privacy of patients), I said that he failed to detect his blindness because of a broken connection between his visual hardware and the brain systems that were supposed to monitor that hardware. But there may be another explanation as well. Though blind to the external world, patients with Anton’s syndrome can still visualize things in their minds. They haven’t been blind their entire lives, so they can still imagine visual images. Many researchers believe this to be the second reason why people with Anton’s syndrome don’t feel that they’re blind: they mistake their own imagined visual images for actual eyesight. So, when Walter said that his neurologist was a “small, fat chap,” it might not have been a simple guess. Perhaps that’s how Walter imagined him.
Walter was able to visualize images in his mind because he wasn’t always blind, but what if he had been? If a person were born blind, would she have any concept of what it is like to see? How would she “visualize” objects or people in her mind? What do the blind “see” in their dreams?
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