Seventy-year-old Orestes Perez used to spend most of his time alone in his room at the Stoddard Baptist Nursing Home in Northwest Washington, making little attempt to socialize with other residents.

But since the arrival a few months ago of a resident named Davey -- a gray cockateel with a yellow crest and distinctive orange cheeks -- Perez appears to have broken out of his isolation.

He seems more interested in his surroundings and more willing to spend time with other people, according to activities director Robert Hood.

"He has become familiar with the bird, become interested in feeding the bird, covering the bird cage at night. And that has gotten him out of his room," Hood said.

When asked about the bird, Perez, a Cuban immigrant who has no family and has been diagnosed as experiencing dementia, or impaired mental powers, smiled warmly at the cockateel perched on his shoulder and explained in Spanish through an interpreter:

"We give love to each other."

Birds, cats, dogs and rabbits have gained a key role in treatment of elderly and disabled patients in Washington and across the country.

"Pet therapy is becoming more and more widespread," said George Baker III, a Silver Spring health care specialist. "And Stoddard demonstrates one way that therapy can be used."

Pet therapy can raise the quality of life for those who live in institutions by keeping them interested and active, Baker said. "It gets them out doing something, taking care of the animal, feeding the animal," he explained.

"As you know, some people have a deep affection for animals."

To see how the program works, a group of gerontologists from around the country is scheduled to tour the Stoddard nursing home Wednesday as part of the 40th annual scientific meeting of the Gerontological Society of America.

At a recent workshop on pet therapy at the National Institutes of Health in Bethesda, researchers agreed that although pets may have no physiological effect on dis- eases, they do have the capacity to make patients feel better, especially in nursing homes.

Susanne Robb, a quality assurance coordinator for the Veterans Administration, told the workshop participants that nursing home residents who are around pets "show more attentiveness, more well- being and less depression, although there is no real improvement in their physical status."

Davey -- along with the Stoddard home's other full-time resident pet, a black, long-eared rabbit named Sugar Pie -- has helped lift the spirits of many elderly and disabled residents who live in the 168-bed facility at 1818 Newton St. NW. "It has made a real difference in their attitudes," Hood said.

While many nursing homes arrange for pets to visit residents, Stoddard's pets live there full time.

"They are rotated from floor to floor so all the residents can enjoy them and assist in caring for them," said human resources coordinator Dawn Humphrey. Both pets are allowed out of their cages during certain hours, she said. "The rabbit hops around the unit. The bird flies around and sits on the residents' shoulders."

The gerontological society's meetings are expected to draw 3,500 specialists from around the country for nearly a week of activities, including presentations on such controversial issues as measures to prolong life, ways to meet the housing needs of elderly and strategies for marketing services for the aging. Also, society officials plan to meet with congressional leaders.

The researchers, educators and other gerontologists are scheduled to visit 11 organizations, including the National Caucus and Center on Black Aged Estates.