"I believe that many people have done everything they can," he said. "And maybe there's some predisposition. Maybe there's some effect that the brain cannot control exactly what we consume."
There are risks associated with the surgery -- from infection and hemorrhaging, and in the most extreme cases (less than 1 percent) paralysis or death. Bailes said the FDA had been "appropriately scrutinizing" the study.
"For some, it may seem radical that elecrodes should be put in the brain, that someone should be doing brain surgery for obesity. But I think we've gotten through that and we are very happy to be able to do the first series of patients here, looking at the effects and possible benefits.
"This is a frontier of medicine, a frontier of neurosurgery, a frontier of neurological disease, to be able to generate tiny pulses of electricity in these deep nuclei of the brain, and to see what effect they may have on behavior, including in this case the behavior of eating and the issue of uncontrolled appetite."
Since there are no pain receptors in the skull or brain, Poe required only a topical anesthetic wash applied to her scalp. She was awake throughout the surgery.
"I'm excited about being awake. I want to be awake," she said. "Because if I'm awake, I'll know everything that's going on."
The neurosurgeons, Drs. Michael Oh and Donald Whiting, drilled about 10 centimeters into Poe's brain, on both hemispheres, through a pathway of tissue that does not affect other functions. When they reached a point in the hypothalamus, which controls the stomach, a wire was introduced that would ultimately carry an electrical impulse. The plan was to alter the level of electricity that's generated by that region naturally, thereby giving Poe the sensation of feeling full.
Oh followed the surgery on a computer, which helped the surgeons find the point at which they'd introduce electrodes.
"Although we are applying this technology for obesity, there are certainly many more possibilities in the near future that are going to be available for people with many neurodegenitive disorders," Oh said.
To some extent, the surgeons are able to evaluate patients' reactions during an awake surgery and talk to them.
"During this procedure, when we have the electrode in this target, we will be asking her about stimulation-induced responses, whether she has a feeling of hunger whether she has any memory responses," Oh explained.
During the surgery, the surgeons can actually provoke a reaction to this electrical current and control the current by adjusting the amount of electricity applied.
Once they get a successful response, doctors "implant a permanent generator, and they have this constant electrical current to that part of the brain," Oh said.
Poe said the procedure didn't hurt but found the stabilization device the doctors put on her head uncomfortable. "It's just real tight," she said. "Like your head is in a vice."
After about an hour of the most delicate movements, doctors believed they'd reached the precise spot. When the electrical current was first introduced, doctors asked Poe if she felt hungry or full, and also whether she felt hot or cold.
"I'm getting warm now," she said. "Yeah, I was cold." The tested electricity was lowered. Poe was unaware of when the doctors signaled for a change in the electrical current, so she couldn't play into what she believed they might want to hear.