In this month’s Ask the Experts column, the following questions are addressed: I’ve heard that the two sides of my brain are specialized for different tasks (language vs. reasoning, etc.). If I listen to a science lecture on my iPod using only one earpiece, will the way I process the information depend on which ear I use to listen to the lecture? and Why does the sound made by scratching a chalkboard seem to be irritating to so many people, and why to some and not others? Nature or nurture or a bit of both?