Lab Report: Health, Science and Medicine

TEENAGERS AND NOISE

Can You Hear Me Now?

Teens aren't known to be the greatest listeners, but a new study reveals that their hearing may be just fine. While more and more adolescents are using headphones to listen to music, researchers at Harvard Medical School found no significant increases in hearing loss among 12-to-19-year-olds since the 1990s. The most obvious sources of noise exposure, the scientists found, were recreational--like loud concerts--or occupational, like working around heavy machinery.

That still doesn't mean that teens' listening habits are safe for the sensitive cells in their ears that translate sound energy into electrical impulses that can be interpreted by the brain. Damage to the cells is cumulative, and the study did not track the teens into adulthood. In addition, when the Harvard team analyzed their sample group by gender, they found that to the extent that there are detectable increases in hearing loss, the problem is greater in girls, suggesting that gender equality now extends to the ear-punishing activities that were once the province mostly of boys. The solution to the problem: earplugs in high-noise environments, which can reduce exposure by 20 decibels.

THE PLACEBO EFFECT

Powerful New Uses For the Completely Useless Pill

At the heart of medicine's placebo effect is the brain's ability to think away symptoms and concoct treatment out of belief. And until now, researchers have been able to achieve this only by misleading subjects--telling them that a fake pill is a real one. But a new study from Harvard Medical School suggests that the placebo effect may work even if patients are entirely aware of what they're taking.

When a group of patients with irritable-bowel syndrome (IBS) were told they were taking a completely inert substance that would reduce their symptoms "via a mind-body self-healing process," 59% reported feeling better, compared with 35% of a similar group who received no treatment at all. Other work showed that patients who believe they will benefit from a placebo show more activity in regions of the brain associated with the anticipation of pleasure and the dulling of pain.

Tapping into these neurological networks may be a way to help those suffering from disorders beyond IBS, providing real relief with no real chemistry. And the latest data hint that it may be possible to do this even when the last bit of trickery the Harvard team used--acknowledging that the pill was a placebo but telling the patients it would work--is left out.

FROM THE LABS

Anxious Mom, Anxious Baby

Expectant moms may be passing along more than just their genes. In a lab study, quails that carried fertilized eggs and were routinely moved to new environments developed more signs of stress and aggressive behavior than other birds did. Their chicks seemed to acquire their mother's stress as well, showing more fearful behavior in novel situations.

The Genetics of Deliciousness