Prime Minister Ariel Sharon showed "slight improvement" in his recovery from a massive stroke by moving his left hand Tuesday, but doctors said they still cannot assess his abilities to think and reason as they gradually reduce the anesthesia keeping him in a coma.

Doctors also said Sharon's life was not in immediate danger.

One of Sharon's sons spoke to him, and the 77-year-old leader's blood pressure increased, one of his doctors said.

Sharon is recovering from a massive stroke and widespread bleeding in the right side of his brain that he suffered nearly a week ago.

As doctors began decreasing Sharon's dose of sedatives to remove him from an induced coma Monday, he moved his right hand and right leg slightly in response to pain stimulation.

On Tuesday, the movement on Sharon's right side increased, and he also moved his left hand, said Dr. Shlomo Mor-Yosef, the director of Hadassah Hospital in Jerusalem.

"These are neurological changes that show slight improvement in Prime Minister Ariel Sharon's brain functioning," he said.

Over the next 24 hours, the doctors will continue decreasing Sharon's sedatives and conducting neurological tests to assess his brain functions, his doctors said.

Dr. Yoram Weiss, one of Sharon's anesthesiologists, said doctors would have to wait several days, until the sedatives have worn off entirely, before assessing the leader's brain function.

"There is improvement, but we still can't know the extent of the cognitive improvement," Weiss said. "There are still drugs that could cause us not to see cognitive improvement."

Sharon remains in critical condition and his life is not in immediate danger, Weiss said.

"More metaphorically speaking, we have backed off five yards from the edge of the cliff," he said.

Dr. Charles Weisman, another of Sharon's doctors, said music was being played in Sharon's room and his blood pressure rose when his son spoke to him. The music being played included Mozart.