It's 2:00 p.m. on a Tuesday, and I'm feeling stupid and slightly grumpy. I have lingering jet lag because I took a trip to London last week and flew in last night from California. Now I'm sitting in the Brain Stimulation Unit of the National Institute of Neurological Disorders and Stroke in Bethesda, MD, with two electrodes affixed to my forehead. In a moment, a researcher in the lab of neurologist Eric Wassermann will activate a gizmo the size of a small clock radio, which will send an electric current through my frontal lobe, the part of the brain most associated with higher reasoning and emotion. For the next 40 minutes, the flow of electrons will create an electric field that lets neurons having to do with cognition and emotion fire more easily.

I'm here to investigate firsthand whether the latest brain gadgets and pills represent a new frontier in neuro­enhancement. Wassermann has already told me that his device will not turn me into an Einstein. He is hoping that in people with brain injuries or impairments from disease, it will stimulate the cognitive centers to function better than they would otherwise. "We are starting with testing healthy people to get a baseline for how the technique works," he says.