dr. peter weber, a neurosurgeon, uses a computer to calculate the safest route to implant electrodes in her brain. >> dr. peter weber: the wires come from the back forward, deep inside the brain. that's the way they look from the front-on view. >> couric: implanted in the skull, the neuro-pace device is smaller than a cell phone. when it's turned on, it immediately detects monica's abnormal brain activity. >> weber: these are abnormal discharges that lead to seizures. >> couric: we followed up with monica three months after the device was implanted. now that you have this device in your brain, what happens when you feel a seizure's coming on? can you explain it? >> lovelace: it doesn't come on. yeah, it doesn't come on. >> couric: monica still gets the familiar sensation that she's about to have a seizure, but now, it usually stops. she showed us how she wirelessly downloads her brainwaves. >> lovelace: this goes over the area where the device is. >> couric: the information is sent by computer to her doctor, who then fine-tunes the stimulation. while the device is still in the early stages,