Medicine: Magnet in the Stomach

When a man has butterflies in his stomach, how fast are their wingbeats? Does anger or anxiety have a greater effect on stomach contractions? Medical researchers trying to answer these questions have been hampered by difficulty in observing what goes on inside the gut. Last week a team of U.C.L.A. psychologists studying automatic nervous reactions announced a compact solution to the problem: a plastic-coated magnet no bigger than a small medicine capsule.

In the psychology lab a student volunteer washed down the magnet with water, then lay down on a bed, fully dressed and in no discomfort. Beneath the bed was a magnetometer detector (a small rectangular box). Wires from the detector led to the control room, where members of the research team watched the magnet’s movements recorded by an automatic pen.

With the subject at rest, the pen recorded gentle waves about 20 seconds apart. If he was given a tricky mathematical problem and became tense, or if he was startled by a starting gun fired near his ear, the waves sped up. In another subject, they might stop entirely. The magnetic capsule gives the researchers plenty of time to work: they have made recordings for as long as five hours. The same technique could be used a day or two later, as the pellet slowly works its way through the digestive tract, to determine how the intestines contract.

The U.C.L.A. researchers have used the gadget only in supposedly normal stomachs to get base-line data. In patients with ulcers, “nervous stomach” or similar disorders, it could be valuable in recording abnormal contractions.