What do ballet and gas pain have in common? How do you know exactly when to blink? How do you know where you are, and what you should do about it?

The answers to these and other intriguing questions will be discussed by three internationally known scientists at the St. Olaf College Science Symposium, "Exploring the Brain: From Molecules to Behavior," Friday. The symposium, from 9 a.m. to 8 p.m. in the St. Olaf Science Center and Buntrock Commons, is free and open to the public.

Each of the three guest scientists will give separate lectures. James R. Bloedel will explain in a lecture titled "Learning to Make a Movement: Why Sometimes Practice Does Make Perfect" why some human movements are second nature and others are very difficult.

Frederick Sachs will talk in his lecture, "Cell and Molecular Mechanics ­ What Touch, Hearing, and Ballet Have in Common," about how the human senses of touch, hearing and balance are related, and how individual cells and molecules are triggered by stimuli.

Carol L. Colby will discuss how humans know where they are in space, and how they use that knowledge to act. Her lecture is titled "How the Brain Explores Space."

In addition to the three plenary lectures, participants will be able to view dozens of posters explaining student research projects. The posters will be displayed throughout the symposium in the Crossroads of Buntrock Commons, and will be exhibited Saturday morning.