Officials are forecasting that hurricane activity will be "above normal" this season, with 13 to 20 named storms. As many as six of those could be major hurricanes. Warm ocean waters and the lack of El Nino conditions are partly to blame.

Melissa Block talks to Jon Hamilton about the science of tornadoes.

The new version of the DSM, the manual of psychiatric diagnoses, is already sparking criticism. But psychiatrists say it helps make sure they're all on the same page.

Unlike cardiology and most other fields of medicine, psychiatry still hasn't developed discrete, biological tests for diagnosing illnesses of the mind. That's because the brain "hasn't yielded its secrets yet," one psychiatrist says.

Scientists used to think that identical twins turned out differently because they were treated differently by friends, teachers or their parents. A study of mice supports the idea that small changes in behavior can lead to larger ones and eventually even resculpt brains in different ways.

Linguists used to think the human brain had a specific region devoted to understanding language. But brain scans now indicate that regions controlling vision, movement, taste, smell and touch are all called into action when we think of a word, too.

Disruptions of sleep are well known as migraine triggers, but now researchers have found a genetic link between the two. In studying families with lots of migraines, they also found a mutation on a gene that helps control circadian rhythms.

When Superstorm Sandy flooded lower Manhattan last year, thousands of lab animals drowned and many scientists lost months or even years of work. The specialty animals can be very difficult to replace, but researchers say the loss of animal life is emotionally devastating and difficult to get over.

Drug companies have developed several Alzheimer's drugs that seemed to work in mice but did not help people with the disease. So scientists inserted human genes into rats in hopes of getting a better model for testing the drugs.

Today's devices are smaller and much more powerful than they were 20 years ago. New advances in technology can't solve all hearing problems, but they've improved many aspects of life for people with hearing loss.

The White House is asking Congress for $100 million to develop new tools for "eavesdropping" on millions of cellular conversations, as individual neurons interact to form thoughts or create memories. The goal is more ambitious than the Human Genome Project, researchers say.

President Obama has unveiled a plan to learn more about the inner workings of the human brain. It calls for including $100 million in the 2014 budget to launch what's being called the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) initiative. The goal is to help researchers find ways to cure or prevent brain disorders including Alzheimer's disease.

A government study of the medical records of 1,000 kids found no correlation between the number of vaccines a child received and his or her risk of autism spectrum disorder. Experts hope the finding will allay some parents who worry that many vaccines on one day or in the first two years of life may lead to autism.

Loneliness and isolation often go hand in hand, so teasing out which factor is harder on health isn't easy. But a British study now suggests that, while loneliness may make you unhappy, it's social isolation that could take years off of your life. Discuss (with a friend).

When abiding fear takes over some kids' lives, they respond with anger and aggression that's not premeditated. One psychiatrist says he's finding profound relief for a particular subgroup of these children in experimental research with the anesthesia drug ketamine.

Deaths from the disease have increased by 68 percent between 2000 and 2010. One reason: We're living longer, and deaths from other causes, like heart disease and prostate cancer, are going down.

Scientists are beginning to understand how people focus on a single voice in a crowded, noisy room. This ability, known as the "cocktail party effect," appears to rely on areas of the brain that have completely filtered out unwanted sounds.

Until recently, our brains' way of connecting food with love and a sense of well-being was purely a good thing. But in a world where it's possible to feast every day, it can be a problem.

Is fracking making people sick? The question has ignited a national debate. A proposed study in northern Pennsylvania could help resolve the issue. By mining more than 10 years' worth of patient records, researchers hope to better understand the potential impact of hydraulic fracturing on health.

The human brain may be just three pounds of jelly. But it turns out that jelly is very organized. New scanning techniques show that the brain's communications pathways are laid out in a highly ordered three-dimensional grid that look a bit like a map of Manhattan.