Have you ever had trouble sleeping in a new place? Lots of people do. And now researchers from Brown University in Rhode Island think they know why. They found that one-half of the brain “remains more awake” than the other half when people are trying to sleep in a new place. This appears a case of the brain keeping people ready for trouble in a new place, the researchers said. The sleep findings were reported in Current Biology and by Brown University. In their report, the researchers said many people report they have a harder time sleeping the first night at a hotel or other places outside their home. They call it, “first-night effect.” “In Japan they say, ‘if you change your pillow, you can’t sleep,’’’ said Yuka Sasaki, one of the report’s authors. “You don’t sleep very well in a new place. We all know about it.” The researchers measured brain waves for 35 volunteers over two nights in a laboratory. The two nights were a week apart. They found during the first night the left hemisphere of the brain was more active than the right hemisphere.