Probing the Brain From Pickled Brains to Present-day Research

By Jeanine DeNoma

The human brain. There is little doubt it holds a special place in our imaginations and in pop culture. It is viewed with intrigue as the center of our intelligence, our consciousness, our "soul," our "self" - whatever these may be.

     When Albert Einstein died on April 18, 1955, the chief pathologist of Princeton Hospital, Thomas Harvey, conducted the autopsy. Harvey examined Einstein's heart, organs, veins, and confirmed Einstein had died of an abdominal aorta aneurysm. Then Harvey did something shocking: He removed Einstein's brain - the brain of the greatest thinker of his time - to keep for himself! Harvey told Einstein's son, Hans Albert, the brain would only be used for research purposes. No reports, however, were ever published. Harvey gave away nearly a third of the brain to various people, mostly researchers of his choosing. He keeps the remainder stored in a Tupperware container of formaldehyde at an undisclosed location.

     The real intrigue of Einstein's brain is not the science, for which it was never used, but for what it stirs in our imaginations. Freelance writer Michael Paterniti recounts in a recent article (Harper's Magazine, October 1997) meeting Thomas Harvey and, in February of this year, driving Harvey and Einstein's brain across the US from New Jersey to California. In a National Public Radio interview, Paterniti said people responded to the brain either with disgust or as if it were a kind of spiritual icon.

     Carl Sagan, in his 1978 book Broca's Brain, describes his tour of Musee de l'Homme which houses the collection of heads, brains and skulls started by the French anthropologist and brain anatomist Paul Broca. Broca died in 1880 and his brain is now among those in the collection. Sagan tells of feeling "the prickle of the hairs on the back of [his] neck" as he examined the collection. There is a horrifying intrigue to seeing jars of neatly labeled, pickled brains - even those collected in the hope of advancing our knowledge - lining the shelves in the back room of a museum.

     While studying these specimens Broca identified a region of the left frontal lobe of the cerebral cortex, now known as "Broca's area," which controls articulate speech. "It was one of the first discoveries of a separation of function between the left and right hemispheres of the brain. But most important, it was one of the first indications that specific brain functions exist in particular locales in the brain, that there is a connection between the anatomy of the brain and what the brain does," writes Sagan.

     Broca was one of many 19th century scientists from the school of craniometry: measuring brain and skull sizes. Broca preferred to measure brains immediately after death. Philadelphia physician Samuel G. Morton, who died in 1851, amassed a collection of over a 1000 skulls of native peoples from all over the world, including from American Indians and Egyptian tombs. He measured the cranial capacity of the skulls and ranked the races by cranial volume, placing whites at top and blacks at the bottom. The seeming objectivity of his numbers belied the fact that they reflected the prevailing prejudices of race and class. In fact, his data was used to support prejudices about the worth and intelligence of the races. In 1977 Stephen J. Gould reanalyzed Morton's raw data and concluded that although there was no evidence of conscious fraud, Morton's summary tables reflected his a priori convictions. For an excellent discussion of Gould's analysis see his book The Mismeasure of Man (pp. 50-69).

     Today brain researchers have many new tools and statistical methods at their disposal. Consequently, research has taken many new and productive avenues. New imaging technology allows researchers to examine a living, active brain in ways Broca and the craniometrists could only have dreamed. Pharmacology has opened the door to studies on brain chemistry. Even consciousness has become a respectable topic for research (see Francis Crick's book The Astonishing Hypothesis).

     There are three general ways of looking at the brains of living individuals, Dr. Joel Alexander explained to me in a short phone interview. One way is structural. He used the analogy of a car. Studying brain structure is like raising the hood and checking the engine parts; with the brain this is done using techniques such as MRI and CAT scans. A second approach is to examine brain function. This is done with EEGs, PET and rCBF; it's analogous to starting the car's engine and observing how well it operates. The third component is behavior analysis; this is like taking a test drive to see how the car runs.

     Alexander studies the electroencephalograms or EEGs of individuals who fall to the extreme ends of the trait under study. The EEG machine amplifies tiny electrical impulses from within the brain, giving a functional scan of ongoing brain activity. From the pattern of these impulses he hopes to detect differences in the underlying brain activity which reflects the individual's extreme behavior. This is called "extreme group design," he explained.

     For example, if the trait under study were musical talent, he would examine EEGs of the most elite musicians. Individuals considered extreme for left handedness had other immediate family members who were also left-handed. In studies of criminality, Alexander selected murderers who planned their crimes and stalked their victims. An individual who had killed his victim on impulse or under provocation did not meet his criteria of "extreme."

     When I questioned him further about extreme group design, he explained that "normal" is so loosely defined and encompasses such a wide range of behaviors that results from studies on normal individuals are often murky and inconclusive. Differences are more easily delineated by looking at a small group of individuals from extreme ends of a trait. The extremes often define the middle and help us to better understand the normal.

     Alexander said he selects for study those traits for which there are natural groups of extreme individuals and for which functional brain analysis may identify unique differences. Traits are also selected for their importance to public concerns and interests.

Begley, Sharon. Gray matters. Newsweek, March 27, 1995 (pp. 48-54). Discusses research showing differences between the brains of men and women.

Golden, Daniel. Building a better brain. Life, July, 1994 (pp. 62-70). Examines evidence that mental exercise increases brains function for people of all ages.

Scientific American. September 1992. Special issue covering research on the brain and how our minds work.