>>...an experiment involving two patients with epilepsy. Both patients were already being monitored for seizure activity using electrocorticography (ECoG), in which a sheet of electrodes is laid directly on the surface of the brain. This procedure requires a craniotomy, a surgical incision into the skull. Dr. Shih and colleagues hypothesized that feedback from electrodes placed directly on the brain would be much more specific than data collected with EEG (electroencephalography) alone, in which electrodes are placed on the scalp. Most studies of mind-machine interaction have occurred with EEG. "There is a big difference in the quality of information you get from ECoG compared to EEG. The scalp and bony skull diffuses and distorts the signal, rather like how the Earth's atmosphere blurs the light from stars," says Dr. Shih. "That's why progress to date on developing these kinds of mind interfaces has been slow."<<
>>...an experiment involving two patients with epilepsy. Both patients were already being monitored for seizure activity using electrocorticography (ECoG), in which a sheet of electrodes is laid directly on the surface of the brain. This procedure requires a craniotomy, a surgical incision into the skull. Dr. Shih and colleagues hypothesized that feedback from electrodes placed directly on the brain would be much more specific than data collected with EEG (electroencephalography) alone, in which electrodes are placed on the scalp. Most studies of mind-machine interaction have occurred with EEG. "There is a big difference in the quality of information you get from ECoG compared to EEG. The scalp and bony skull diffuses and distorts the signal, rather like how the Earth's atmosphere blurs the light from stars," says Dr. Shih. "That's why progress to date on developing these kinds of mind interfaces has been slow."<<