Scientists begin recruiting mothers-to-be in North Carolina and New York this week for the largest study of U.S. children ever performed — aiming eventually to track 100,000 around the country from conception to age 21.

“We are embarking on the road to discovering the preventable causes of the major chronic diseases that plague American children today,” Dr. Philip Landrigan of the Mount Sinai School of Medicine, one of the lead researchers, declared Tuesday.

Nearly a decade in the planning, the ambitious National Children’s Study tackles a major mystery: How the environment — everything from a pregnant woman’s diet to a child’s exposure to various chemicals — interacts with genetics to affect youngsters’ health and development.  This type of study is great and looks to providing important data for the next generation.

A recent study found that people who are good at interpreting facial expressions have “mirror neuron” systems that are more active, say researchers. The finding adds weight to the idea that these cells are crucial to helping us figure out how others are feeling.  Mirror neurons are brain cells that fire both when you do something and when you watch someone else do the same thing.

Because they allow us to mimic what others are doing, it is thought that these neurons may be responsible for why we can feel empathy, or understand others’ intentions and states of mind. People with autism, for instance, show reduced mirror neuron activity during social cognition tasks. I guess it is true that we only understand about 15% of how the brain works.