The miracle fruit from West Africa has a chemical that binds to and boosts sweet taste receptors in the presence of acidic foods. Courtesy of Keiko Abe hide caption

itoggle caption Courtesy of Keiko Abe

The brain "seems to be specialized in alerting us to things that are emotionally important to us — either positive or because they're scary," a scientist says. iStockphoto.com hide caption

itoggle caption iStockphoto.com