Brain on Fire

Langleben's fictional scenario is that the subject is applying for a job as a writer at the lab. The reporter submits a résumé in which he carefully includes 16 lies -- some of them whoppers, like that PhD from MIT -- but many of them more subtle, like the bachelor's degree he actually didn't get from that university he attended for four years. In this case, Langleben selects three truths and three lies from this résumé and prepares them as yes/no questions to be displayed on the fMRI's screen. ("Is this your house?" "Did you serve in the military?")

Each of these six questions is accompanied by a picture. "Do you work for The Post?" for example, is accompanied by a picture of a Washington Post front page. The images that go with the lies are concoctions -- a phony diploma, phony Marine discharge papers, and a copy of the cover of the magisterial book "Lying: Moral Choice in Public and Private Life," in which the name of the author, Harvard's Sissela Bok, is, with her permission, replaced by the name of the reporter.

Langleben keeps the rest of the lab team blinded to what is true and what is a lie.

On the big day of the trip into the fMRI machine, the reporter is asked an astounding number of preparatory questions. Was your mother right-handed? Have you ever taken antidepressants? Have you ever worked with welding machinery and is there any possibility you've got any metal imbedded in your eye?

The reporter's date of birth makes them nervous. He is significantly more a geezer than the sort of grad student subjects they usually use. Will the decrepitude of his brain affect how it actually works?

No one knows the answer. Nonetheless, they prepare him and the giant machine for a rendezvous with deviousness.

Nature's Fibs

Lies have been around for a very long time. Only four pages into Genesis, the Lord asks Cain, "Where is Abel your brother?" and he replies, "I do not know; am I my brother's keeper?"

Deception is a fundamental part of evolution, establishing who eats and who is eaten. Gorillas and chimpanzees routinely lie to obtain food and attract mates. Birds feign a broken wing to lure a raptor away from the nest. Even a tasty species of butterfly deceives about its delectability by emulating another species with a bitter flavor.

Attempts to detect lies are almost as venerable. According to an ancient tale from India, a village turns out to have a thief. To determine who it is, a wise man puts into a dark tent a donkey he says has magical powers: if a guilty man pulls his tail, the donkey will sing. When every man in the village, one after the other, has entered the tent to pull the donkey's tail, the wise man then lines them all up, and sure enough, the identity of the thief is obvious. Turns out the wise man had covered the donkey's tail with lamp black, and only one man had clean hands.

Harnessing science to truth-telling is scarcely 100 years old. One of the early contributors was the psychologist William Moulton Marston. He invented the systolic blood-pressure test as a "lie detector" that is still a component of the polygraph. With another part of his brain, he also invented "Wonder Woman," with her lasso that forced scoundrels to tell the truth.

The polygraph, which means "many writings" in Greek, is so called because it records a variety of physical reactions simultaneously -- such as blood pressure, heart rate, sweating and breathing. As a lie detector it entered widespread use in the second half of the 20th century. It was soon joined by other dubious means to detect deception, including voice stress analysis, psychological profiling and "truth serum."

Polygraphs are so notoriously unreliable -- they are rarely admitted as evidence into court -- that an $860,000 National Academy of Sciences' National Research Council report concluded in 2002 that "polygraph testing" is "intrinsically susceptible to producing erroneous results." In a hypothetical group of 10,000 government employees that included 10 spies, the report says, even if the polygraph achieved better results than is usually found in the field, it would still miss two spies and falsely accuse 1,598 innocents. If it were set to greatly reduce the false positives to only 39 innocents, it would miss eight spies.