Cell phones now make the tiniest windows of time entertaining, and potentially productive. But scientists point to an unanticipated side effect: when people keep their brains busy with digital input, they are forfeiting downtime that could allow them to better learn and remember information, or come up with new ideas. At the University of California, San Francisco, scientists have found that when rats have a new experience, like exploring an unfamiliar area, their brains show new patterns of activity. But only when the rats take a break from their exploration do they process those patterns in a way that seems to create a persistent memory of the experience. The researchers suspect that the findings also apply to how humans learn.
The prevalence of hearing loss in teenagers rose by nearly one-third in recent years compared with the rate in the 1980s and 1990s, a new study shows. The findings come as a surprise to the study's authors, who had expected overall hearing to improve thanks to publicity about the risks of exposure to loud music and the advent of childhood vaccines against meningitis and pneumonia that can prevent many ear infections. Scientists report that the portion of U.S. adolescents aged 12 to 19 with any hearing loss rose from 14.9 percent during the 1988 to 1995 period to 19.5 percent in 2005 and 2006. While noise exposure is a known culprit, diet, medical care, lack of exercise and obesity may also play a role.