Scientists are placing robotic dogs in the homes of lonely old people to test whether they can improve the quality of life for humans. Alan Beck, an expert  in human-animal relationship, and Nancy Edwards, a professor of nursing, are leading the animal-assisted study on the effect of robotic dogs on old people's depression   , physical activity, and life satisfaction. In the study, the robot, called AIBO, is placed for six weeks in the houses of some old people who live alone. Before placing AIBO in the home, scientists will collect baseline data  for six weeks. These old people will keep a diary to note their feelings and activity before and after AIBO. Then, the scientists will review the data to test if it has produced any changes in the life of its owner. "I talk to him all the time, and he responds to my voice," says a seventy-year-old lady. "When I'm watching TV, he'll stay in my arms until he wants down. He has his own mind." The AIBOs respond to certain orders. The scientists say they have some advantages over live dogs, especially for old people. Often the elderly are disabled and cannot care for an animal by walking it or playing with it. A robotic dog _ exercise and feeding concerns. "At the beginning, it was believed that no one would relate(......) to the robotic dog, because it was metal and not furry." Beck says. "Hopefully, down the road, these robotic pets could become a more-valuable health helper. They will record their masters' blood pressure, oxygen levels or heart rhythms . AIBOs may even one day have games that can help stimulate  older people's minds." The purpose of Beck and Edwards' study is to   _  .
understand human-animal relationship make lonely old people's life better find the causes of old people's loneliness improve the animal-assisted research