On the laboratory’s kitchen counter, Zitzelberger spreads out two circular diagrams that show the activities of two volunteers in their homes for one full year. Among the many colored dots that indicate the rooms in which activity occurred, she starts to point out minute details that suggest sudden changes in the subjects’ behavior. “See this activity at night in the second half of the year? This person’s sleeping habits changed notably.” These are the types of variations the motion detectors see unfailingly and they are what may help point out changes early on. Early detection helps seniors plan an appropriate level of care, but it’s also especially important because many causes of cognitive decline are triggered by problems other than Alzheimer’s, and many of those are easy to treat. Depression, for instance, as well as diabetes, thyroid deficiency, high blood pressure caused by improper medicine dosages, or even urinary tract infections can affect cognitive function in seniors. The longer these conditions go untreated, the more dangerous they become.

Yet the benefits of Kaye’s type of assessment go beyond early detection. A particularly promising benefit of passive monitoring is that it transcends a problem endemic to medical studies on aging populations, one that creates a sort of apples-to-oranges comparison. “The people you end up enrolling in medical studies are usually people who are mobile, people who can drive, people who retain a high level of cognitive function,” Kaye says. “Therefore, you have treatments and medicines being developed and tested on people who are about a decade younger than the people who need them, who are generally sicker and frailer.” Kaye’s study, on the other hand, compares test subjects, quite literally, to themselves.

From her apartment window, Jean looks out across the Willamette River toward several sprawling mansions that line its west bank. “I just can’t imagine what they do with all that space,” she says. She’s lived here for nine years, the first year with her husband Bill, who died in 2000. She’s been a volunteer participant in Kaye’s project for a little more than two years.

Though neither of her parents developed dementia, Jean’s sister Mary was diagnosed with Alzheimer’s two years ago. Signs of Mary’s decline had been evident in phone calls years before that. Jean sees this kind of memory loss regularly among the more than 300 people at Willamette View, in Milwaukie.

“We see it happen here all the time,” she says of the community. “All of a sudden residents will get lost in the building. They start forgetting things. You just get the feeling … that you have the responsibility to do anything you can to help.”

More than half of the participants in Kaye’s study, including Jean Lindsay, have even offered to donate their brains to the program for further research after they die. Jean says she felt absolutely no apprehension about the decision and attributes her scientific interest, in part, to her mother, who graduated from Northwestern Medical School in 1900.

As for the monitors, Jean barely notices them anymore. The study requires little of her other than tolerating this slightly voyeuristic presence (though no actual images of the subjects are ever recorded) and responding to a periodic questionnaire. Once a week, after she logs on to her computer, nine questions appear on-screen. Have you been sick? Have you fallen down? The questions are designed to help explain a housebound week, for example, or a spate of restless nights. Kaye admits that it’s difficult to say what will become of these many millions of incoming bits of data. The information will probably keep researchers busy for decades as they look for patterns in subjects’ movements and explore the recesses of subjects’ donated brain tissue.

The tissue studies will focus on the hippocampus, the small, curved section located at the base of each hemisphere; it is here, in the area that is thought to play a role in emotion and the creation of new memory, that evidence of Alzheimer’s and other types of dementia is most prominent, showing up in nerve tissue as abnormal protein accumulations. Matching these studies with the subjects’ medical outcomes, and with the living histories produced by the motion sensors, will require the synthesis of an enormous amount of information. But having unprecedented access to the actions of the very population he’s trying to heal is, Kaye says, a significant step in the right direction. Volunteers such as Jean Lindsay may not live to see their generosity rewarded, but if Kaye succeeds, future generations will.