It certainly sounds like Rep. Giffords is making remarkable progress. Head injuries are very tricky under the best of circumstances, but she's doing very well:

TUCSON - Rep. Gabrielle Giffords was upgraded from critical to serious condition Sunday after doctors determined that there were no complications from having her ventilator removed a day earlier.

In a statement released Sunday afternoon, Tucson's University Medical Center reported that Giffords "continues to do well. She is breathing on her own. Yesterday's procedures were successful and uneventful."

Giffords (D-Ariz.) was among 19 people shot during a rampage at a campaign event Jan. 8; six died and 13 were injured in the assault, allegedly carried out by Jared Lee Loughner.

Ten of the survivors have been released from the hospital and two others are listed in good condition, medical officials said.

Giffords is breathing on her own through a tube inserted in her windpipe. She had been breathing independently, but the ventilator had been in place as a preventive measure.