AS PART OF MY JOB reporting on neuroscience, I found myself in an unusual situation 10 years ago. During an interview, I offhandedly told a researcher to contact me if he ever needed a volunteer for a study. Months later the neurologist actually called, and I enrolled in a project on Parkinson's disease.
My dopamine levels turned out to be very high, “the highest we've seen in a normal volunteer,” the neurologist told me. But he and his colleagues had also found something unsuspected. They wanted me to undergo magnetic resonance imaging (MRI) to highlight one particular area. Alarmed, I agreed, and a few days later they took the MRI scan. There, in a dark corner of my cerebellum, was a large ghostly-white mass. It wasn't pretty. The researcher, who was not a physician, shrugged uncomfortably. The radiologist said nothing. Many hours later the neurologist called and told me the shadow indicated a cyst and not to worry. I had probably had it since I was born.