Arizona congresswoman Gabrielle Giffords is responding to family and friends after being shot in the head during an assassination attempt which left six people dead, doctors have confirmed.
Ms Giffords has been able to move both arms and legs and opened her left eye to try and look at a gathering of people she knows around her bed.
Neurosurgeon Dr Michael Lemole said the development means that the 40-year-old is aware of her surroundings and it was likely she opened her eye because of the unexpected stimulation from so many people she knows.
Doctors, who have not yet given Ms Giffords any medication, have sat her up on the side of the bed and dangled her feet over the edge. The three-term Democrat still has a breathing tube in her throat and is unable to talk.
President Barack Obama honoured the victims of the shooting in an address to more than 14,000 people gathered at the University of Arizona basketball arena in Tucson.
Suspected gunman Jared Loughner, 22, has been charged with several offences after the incident outside a Tucson supermarket on Saturday.