Searching for the "Free Will" Neuron

Gabriel Kreimans single-neuron measurements of unconscious decision-making may not topple Descartes, but they could someday point to ways we can learn to control ourselves.

It was an expedition seeking something never caught before: a single human neuron lighting up to create an urge, albeit for the minor task of moving an index finger, before the subject was even aware of feeling anything. Four years ago, Itzhak Fried, a neurosurgeon at the University of California, Los Angeles, slipped several probes, each with eight hairlike electrodes able to record from single neurons, into the brains of epilepsy patients. (The patients were undergoing surgery to diagnose the source of severe seizures and had agreed to participate in experiments during the process.) Probes in place, the patientswho were consciouswere given instructions to press a button at any time of their choosing, but also to report when theyd first felt the urge to do so.