The brain cortex is like a city; every part has an address. Instead of a city's east or west side, the cortex has a left and right hemisphere. The folds and ridges in the hemispheres are like cross streets, and medical students must memorize every one. The cortex also has four lobes—the frontal (in front), the parietal (on top), the occipital (at the back), and the temporal (on the side). A brain "address" can specify left or right hemisphere, the lobe, the nearest ridge or fold, and whether the location is on top or bottom, inside or out, and front or back. Phineas was injured most seriously on the inside of the left frontal lobe, but scientists are still arguing about the exact address. Illustration by David Macaulay
same way. How the neurons inside those folds and ridges connect is what makes every human being singular.
After this tour of the outside of the brain, what you and the Boston doctors in 1850 still lack is a map of the nerve cells. In 1850, die Boston doctors know very little about any kind of cell, even though the cell revolution is getting under way in Germany, thanks to Matthias Schleiden and Theodor Schwann. Working independently, they both revisit the work of Robert Hooke, the microscope observer who came up with the name cell in 1665. Hooke, they realize, was seeing empty cork cells because they were dead. Now, for the first time, Schleiden sees living cells in plants. Schwann sees them in animal tissue. Together, they realize that the cell is the fundamental unit of life. Everything alive, from slime molds to human beings, is composed of cells. It is the stuff inside the cell that controls every process of life, from digestion to reproduction.
As a living organism becomes more complex, its cells differentiate—that is, they specialize. A line of cells will differentiate and become muscle cells. Another will differentiate and become nerve cells. All complex animals have nerve cells, but no animal has as many nerve cells as humans do. Your brain and spinal cord have about 100 billion neurons.
A neuron is basically a wire with plugs at each end. Unlike most wires, most neurons have many, many plugs so they can both relay messages and switch
The nerve cell, or neuron, is a living, one-way wire with switches at both ends. Messages arrive chemically in the dendrites, where they are converted to electrical impulses, which travel down the axon, the long body of the cell. At the terminal on the far end, signals are converted back into chemical messengers, called neurotransmitters, for the short voyage across the synapse to the dendrites of the next neuron. Amazingly, neurons can work as fast as thought. Illustration by David Macaulay
Here two human nerve cells show off their intricate network of axon terminals and dendrites. These connections are so fine that they cannot be seen through a conventional light microscope. A scanning electron microscope (SEM) was used here to capture the details. SEM photograph by Andrew Leonard, Photo Researchers Inc.
them. A neuron is a long, skinny cell with a tangle of receivers at one end called dendrites, a long connector called an axon in between, and at the other end a smaller tangle of transmitters called axon terminals. Neurons never actually touch one another or splice together. There is always a tiny gap between the axon terminal of one neuron and the dendrite of the next. The gap is called a synapse. It is bridged by signaling chemicals called neurotransmitters. A message travels as an electrical impulse through the axon, down the body of the nerve cell, to the axon terminal. There the electrical impulse is converted into a chemical neurotransmitter to float across the synapse to the next neuron. Here's where the complications begin. In your brain, your neurons have lots of choices. Your brain has lots of synapses because the neurons are layered and clumped together so that the number of possible connections is huge. Each neuron can have anywhere from 1,000 to 6,000 synapses. That means the 10 billion neurons in your brain and spinal cord have a possible 10 trillion synaptic choices to make. Complexity is good. Making synaptic connections is how your brain actually thinks, learns, remembers, acts, and reacts.
The Boston doctors watching Phineas in 1850 haven't a clue about neurons, which won't be discovered for another twenty years. Still, these doctors know that the brain sits atop the spinal cord, a thick, bundled cable of thousands of threads. Doctors do not know that each thread is a bundle of microscopic neurons. They do know that cutting the spinal cord results in paralysis. The higher the break in the spinal cord, the more complete the paralysis. They know that if the cord is cut at the base of the brain stem, the patient dies.
That's why Phineas interests the doctors. His injury is not at the back of his head in the cerebellum or at the bottom of the brain near the brain stem. He was struck through the forehead, and the iron must have pierced the frontal lobe of the cortex. If Phineas survived with a large piece of his cortex destroyed, then what does the cortex do? Across America and Europe, doctors are fiercely divided over this very question. These are the two rival schools. One group thinks the brain is a "whole intelligence," that is, that your brain is one interconnected "mind." Let's call them the "Whole Brainers." They think of the cortex as a chamber holding a formless cloud or jelly driven by a mysterious "vital force." Through this force, every part of the brain is connected to every other part. The Whole Brainers believe that thoughts and commands can originate anywhere in the brain jelly/cloud and flash into action. If one part of the brain is injured, then the functions or thoughts that came from there will flow to another part.
Unfortunately, the Whole Brainers have no hard evidence for their theory. Instead they must look for unusual cases that might back them up. Phineas seems to be such a case. Dr. Bigelow of Harvard thinks so. He is a Whole Brainer.
His opponents believe in "localized function"; that is, they believe that the brain is divided into specific areas that control specific things. Let's call them the "Localizers." They are followers of the Austrian Dr. Gall, who started the brain revolution by declaring that the brain was the seat of intelligence, emotions, and will. Dr. Gall called his brain science "phrenology" (a made-up Greek word). By any name, the Localizers, or Phrenologists, believe that "organs" inside the brain control specific functions. They draw up a model Phrenological Head to show the "organs" in their correct positions. The "Organ of Veneration [respect]" and the "Organ of Benevolence [kindness]," for example, are supposed to be just above the left eyebrow. (Remember where Phineas was hit by the iron? Stay tuned.) Unfortunately, the Phrenologists have no way of knowing which part of the brain controls what. "Benevolence" cannot be seen on the outside of the brain.
Later in the nineteenth century, scientists will discover that a weak electrical current applied to the exposed brain of a laboratory animal will make certain
A Phrenological Head is definitely an eye-catcher—bald as a billiard ball and each "organ" carefully outlined and labeled. By the middle of the nineteenth century, a popular parlor game is "reading" one's character by feeling the skull for bumps and dips and then matching them to a head chart such as this one. Hulton Collection, Getty Images
muscles twitch involuntarily and certain senses sharpen or go dead. In the early twentieth century, scientists will invent more sophisticated and less dangerous ways to "see" brain activity. Eventually they will chart the brain's electrical signals by attaching electrodes to the scalp for an "electroencephalograph," or EEG. The EEG plots amazing patterns of electrical activity that match specific areas of the brain with specific functions. Toward the end of the twentieth century, scientists will invent brain scanners that can "image" the electrical and chemical activity inside a living brain.
Back in 1850, the Localizers/Phrenologists haven't seen a single thought or brainwave. Still, that doesn't stop them from identifying thirty-seven "organs" of the brain. How do they do it? Bumps. That's right. Bumps on the head. The Phrenologists reason that if you have a strong organ, it will be big and project from your skull as a bump. If you have a weak organ, it will be small and you'll have a dip or depression in your skull. Run your hand over your own skull and you will find all sorts of knobs, bumps, dips, and so on. The Phrenologists decide that if you have a bump ove
r your Organ of Amativeness, you are a person with a strong talent for physical love. If you have a dip or a depression over your Organ of Philoprogenitiveness (also known as parental love), you're not going to be fond of children.
Among Boston doctors, phrenology is considered serious stuff when Phineas walks into the middle of the debate of the Whole Brainers versus the Localizers. Both sides seize him as proof of their belief. Dr. Bigelow and his fellow Whole Brainers say that Phineas would surely have died if specific areas of the brain were vital to specific functions. After all, the tamping iron carried away pieces of Phineas's brain. If every part of the brain was vital, then he should be dead. Yet here is Phineas alive in Boston, walking, talking, and taking care of himself. Therefore, say the Whole Brainers, the whole brain must be able to perform any function of one part.
On the other side, Dr. Harlow is a Localizer, or at least he is a friend of some leading Localizers/Phrenologists. The Localizers say Phineas proves their theory. The tamping iron has not killed him because the damage is limited to specific organs that are not critical to life. Yet the Localizers/Phrenologists don't have all the facts. In 1850, when Phineas comes to Boston, Dr. Harlow feels he must keep the details of his patient's personality problems confidential, but he does tell some of the truth to Dr. Nelson Sizer. Dr. Sizer is a big man in phrenology and lectures on it all over New England. Dr. Harlow leaks the information to Dr. Sizer that the "completely recovered" Phineas is not the old Phineas. Dr. Sizer tries to disguise the source of his report to the American Phrenological Journal in 1851, writing, "We have been informed by the best authority that after the man recovered, and while recovering, he was grossly profane, coarse, and vulgar, to such a degree that his society was intolerable to decent people."
Dr. Sizer's report is wonderful news for the Localizers/Phrenologists. As Dr. Sizer explains, "If we remember correctly, the iron passed through the regions of the organs of BENEVOLENCE and VENERATION, which left these
An MRI scan allows us to look inside a living person's head and see a slice of everything from the throat to the spinal cord. Inside the brain, you can see die different lobes of the cortex; the corpus callosum, which joins the two hemispheres; the cerebellum at the back of the head; and the brain stem. Compare this to the phrenological chart on [>]. MRI scan by Scott Canzine and Sue Trainor, Photo Researchers Inc.
organs without influence in his character, hence his profanity, and want of respect and kindness."
In the long run, the Localizers will turn out to be somewhat right about localization but completely wrong about phrenological organs. The Whole Brainers will turn out to be right about the complex interconnections of the brain but wrong about the brain acting as a whole. The 10 billion neurons in your brain are not connected at random. They are organized into "local circuits" within the cortex; the local circuits form "subcortical nuclei," which together form "cortical regions," which form "systems," which form "systems of systems," which form you.
Specific areas of the brain do control specific functions and behaviors, but it's not always as "logical" as we would imagine. Skills that you think should be in the same brain patch are scattered about in different places in the cortex. Different areas of the cortex let you recognize letters in a book or faces in a crowd, or know whether you are standing upright. Yet many of these localized functions are also controlled by interactions with other parts of the brain. The human brain, it turns out, is both localized and interconnected. We know so much more about the brain today than the Phrenologists and the Whole Brainers did in 1850, yet we really understand only the rough outlines.
Back in 1850, Dr. Bigelow tells the Boston doctors, "Taking all the circumstances
This ceramic bust by L. N. Fowler was to help serious phrenologists locate the thirty-seven "organs" of the brain while feeling around on the head for bumps and dips. Phrenology lost credibility as science found better ways to probe the brain. Compare this to the "coronal" MRI on [>]. Photograph by D. Parker, Photo Researchers Inc.
Around 1920, a group of Harvard Medical School students gather around the skull of Phineas Gage. The life-size plaster model of Phineas's head made by Dr. Bigelow stands on the left corner of the table. Time has made the skull fragile, but Phineas Gage's fame still draws visitors to Harvard's Countway Library to look without touching. Photograph from the Warren Anatomical Museum, Countway Library of Medicine, Harvard Medical School
into consideration, it may be doubted whether the present is not the most remarkable history of injury to the brain which has been recorded." He also announces that Mr. Gage has graciously agreed to donate his famous tamping iron to the Harvard Medical College. Dr. Bigelow donates the plaster head of Phineas to go with it. The plaster head remains in Boston, but Phineas and his tamping iron soon slip out of town.
Following Phineas Gage
The story of Phineas Gage is famous, and when people repeat famous stories they have a tendency to improve them. The famous story about Phineas says that after hanging around the Boston medical school for weeks, he grows bored and restless. Phineas takes back his tamping iron and hits the road, traveling from city to city through New England and ending up at P. T. Barnum's American Museum on Broadway in New York City. Barnum's museum has nothing to do with our modern idea of a museum. It is a freak show.
In Barnum's time, people will pay to see "living giants," "bearded ladies," and calves born with two heads. People have always gawked at strange and unusual things. Barnum's special genius is "improving" the unusual. Hype and humbug make Barnum's museum a roaring success. He pulls in the crowds with half-fakes like the "Woolly Horse," a strange, long-haired horse that Barnum declares is a newly discovered species, being part deer, buffalo, elephant, camel, and sheep. At least the Woolly Horse is a real horse. Barnum's "mermaid" is a total fake, a counterfeit fossil pasted together from bones, withered skins, and who knows what else. Barnum shows his "mermaid" alongside real exotic animals like orangutans and grizzly bears. Barnum floods the exterior with the brightest lights in all of New York. Inside, the lighting is deliberately dim. The noise is deafening, with actors, jugglers, and glass blowers working the crowd.
In this wild scene, would anyone notice an ordinary-looking young man with a bad scar on his forehead holding an iron rod? It is said that Phineas exhibited himself and his tamping iron at Barnum's. The most colorful description of Phineas at Barnum's museum comes from Alton Blackington, a Boston radio and TV reporter who broadcasts his account a century after Phineas's death. Blackington says that Barnum's museum billed Phineas as "The Only Living Man With a Hole in His Head." According to Blackington, "The poster and one-sheets depicted a husky young man smiling broadly in spite of a huge iron bar which stuck out of his head. Actually, of course, the iron bar no longer protruded from Gage's head but he had it with him, and another skull, also perforated. During his sideshow performances, he would shove the long iron through the holes in his extra skull to demonstrate just how he was
Phineas Gage's mother said her son exhibited himself here at P. T. Barnum's American Museum on Broadway in New York City Barnum was the gaudiest showman and greatest hoaxer of his age. Did Phineas Gage, The Man with a Hole in His Head, fit in with the other human oddities and strange wonders that Barnum promoted here with hype and hoopla? Photograph circa 1850 from the Hulton Collection, Getty Images
injured. All the details were to be found in a pamphlet he sold, and by paying ten cents extra, skeptics could part Gage's hair and see his brain, what there was left of it, pulsating beneath the new, thin covering."
Blackington spins a great yarn. Unfortunately, we don't know if the details are true. Phineas's mother did tell Dr. Harlow that after leaving Boston, Phineas and his tamping iron visited "most of the larger New England towns and New York, remaining a while in the latter place at Barnum's with his iron." But that's as far as the details go, and Blackington's sources can't be found. In our time, Professor Malcolm Macmillan, an Australian psychologist who is the world's leading expert on
Phineas Gage, makes a massive effort to track down the story. Professor Macmillan turns to experts on Barnum, old newspaper files, contemporary diaries, and circus museums. He can't find Phineas anywhere. As far as Professor Macmillan can determine, Dr. Harlow is the only reliable source. Dr. Harlow says that after Phineas leaves Boston in 1850 he gets information about his former patient only from Phineas's mother.
Her name is Hannah Trusell Swetland Gage. She says that Phineas returns from New York to the family's New Hampshire home early in 1851 to work for Mr. Jonathan Currier in his livery stable in the nearby town of Hanover. Whatever Phineas's problems with people, he gets on well with horses. He works in Currier's stable for a year and a half. His health is good, his mother remembers. He seems happiest with children and animals. Then, in 1852, he meets a stranger in Hanover who has big plans to set up a stagecoach line in South America between Valparaiso and Santiago, Chile. He could use a man who is experienced with horses. In August 1852, Phineas leaves New England forever, bound for Chile and a new life as a stagecoach driver.
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