In the 1800's, anatomy had reached a point of sophistication that allowed medical artists to make such intricate drawings that modern surgeons could still benefit from them.  But there was always a limitation involved:  It was one thing to carve up a dead brain -- quite another to actually see a living brain at work.  In the late 1800's and throughout the 1900's, we see some remarkable efforts at exploring the brain without removing it from its owner:  First, Wilhelm Konrad Roentgen invents the x-ray in 1895.  A remarkable tool for physicians and researchers, it proves less useful when it comes to the soft tissues of the brain.  In 1972, Godfrey Hounsfield added the computer to the x-ray and developed computerized (axial) tomography -- the CT (or CAT) scan -- which sums multiple extras into a far more detailed three-dimensional image.

In a very different approach,  Hans Berger developed the first electroencephalogram (EEG) in 1929.  In 1932, Jan Friedrich Tonnies created the first modern version, with its moving paper and vibrating pens.  The EEG records the minute electrical coordinated pulses of large number of neurons on the surface of the cortex.  It was only a matter of time before researchers added the computer to the equation.

In 1981, the team of Phelps, Hoffman, and TerPogossian developed the first PET scan.  The PET scan (positron emission tomography) works like this:  The doctor injects radioactive glucose (that’s sugar water) into the patient’s bloodstream.  The device then detects the relative activity level -- that is, the use of glucose -- of different areas of the brain.  The computer generates an image that allows the researcher to tell which parts of the brain are most active when we perform various mental operations, whether it’s looking at something, counting in our heads, imagining something, or listening to music!

In 1937, Isidor I. Rabi, a professor at Columbia University, noticed that atoms reveal themselves by emitting radio waves after first having been subjected to a powerful magnetic field.  He called this nuclear magnetic resonance or NMR.  This was soon used by scientists to identify chemical substances in the lab.  It would be many years later that a Dr. Raymond Damadian would recognize the potential of NMR's for medicine.

Damadian is an interesting and controversial person.  He was born in New York City in 1936.  When he was only eight years old, he was accepted by the Juilliard School of Music.  He was awarded a scholarship to the University of Wisconsin at Madison, and then went on to medical school at the Albert Einstein College of Medicine of the Yeshiva University in the Bronx.  He received his MD in 1960 at the tender ago of 24.  From there, he began medical research at Brooklyn's Downstate Medical Center.

Investigating tumors in rats, he noted that the NMR signals from cancerous tumors were significantly different from the signal from healthy rats.  He hypothesized that the reason was the larger number of water molecules (and therefore hydrogen atoms) in these tumors.  His findings were published in Science in 1971.

Realizing that this was the basis for a non-surgical way to detect cancer, he got the idea for a large-scale NMR device that could record the radio waves coming from all the atoms in a human being.  You only had to create a magnetic field big enough!

In 1977, he and his students built a temperamental prototype of the modern MRI -- magnetic resonance imaging -- which they called the Indomitable.  He tried it, unsuccessfully, on himself first, then on a graduate student named Larry Minkoff.  The result was a mere 106 data points (recorded first in colored pencils!) describing the tissues of Minkoff's chest.  The Indomitable is now in the Smithsonian.

Damadian's story continues with his recording of a patent and years of litigation trying to fight off companies like Hitachi and General Electric who disputed his patent.  He has also stirred up controversy by supporting the work of so-called "creation scientists."

There have been a number of other scientists studying NMR who were in fact heading in the same direction as Damadian.  One person in particular with a legitimate claim to co-discovery is Paul Lautenbur. He developed the idea of using small NMR gradients to map the body while at SUNY Stony Brook.  In 1973, he used his technique on a test tube of water, and then used it on a clam.  His work was published in Nature, and it is his technique that is favored today.  Lautenbur and British MRI researcher Peter Mansfield were awarded the Nobel Prize in 2003.

The MRI works like this:  You create a strong magnetic field which runs through the person from head to toe.  This causes the spinning hydrogen atoms in the person’s body to line up with the magnetic field.  Then you send a radio pulse at a special frequency that causes the hydrogen protons to spin in a different direction.  When you turn off the radio pulse, the protons will return to their alignment with the magnetic field, and release the extra energy they took in from the radio pulse.  That energy is picked up by the same coil that produced the energy, now acting like a three dimensional antenna.  Since different tissues have different relative amounts of hydrogen in them, they give a different density of energy signals, which the computer organizes into a detailed three-dimensional image.  This image is nearly as detailed as an anatomical photograph!

On the more active side, direct electrical stimulation of the brain of a living person became a fine art in the 1900's.  In 1909, Harvey Cushing mapped the somatosensory cortex.  In 1954, James Olds produced a media sensation by discovering the so-called "pleasure center" of the hypothalamus.  By the end of the century, the specialized areas of the brain were pretty well mapped.

Brain surgery also became more effective.  In the process of looking for surgical relief for extreme epilepsy, it was discovered that cutting the corpus callosum, which joins the two hemispheres of the cerebral cortex, greatly improved the patients' condition.  Roger Sperry was then able to discover the various differences between the left and right hemisphere in some of the most interesting studies in history.  He was awarded the Nobel Prize for his work in 1981.

The other aspect of technology is its use in attempting to heal people with mental illness.  Although extremely controversial to this day, the evidence strongly suggests that electroshock therapy, first used by Ugo Cerletti and Lucino Bini in 1938, can be effective in the care of very depressed patients.  Electroshock (also known as electro-convulsive therapy or ECT) involves sending a strong electrical current through an anesthetized patient's brain.  When they awake, they cannot seem to recall several hours of time before the procedure, but also feel much less depressed.  We aren't sure why it works.

Less effective and much more radical is the lobotomy, first used on human beings by Antonio Egaz Moniz of the University of Lisbon Medical School, who won the Nobel Prize for his work in 1949.  The lobotomy was turned into a mass-production technique by Walter Freeman, who performed the first lobotomy in the U.S. in 1936.  To read more about lobotomy, click here.