Dubbed the Harvard Automated Phone Task, it involves three things an elderly person may need to do via phone in the course of their daily lives: refill a prescription, select a new primary care provider through an insurance company, and complete a bank transaction. 

Researchers asked 77 cognitively normal older adults to complete the assessment, as well as to undergo brain scans. Participants with elevated levels of amyloid—a type of protein that forms plaques in the brains of Alzheimer’s patients—who performed poorly when attempting to choose a new primary care provider tended to have elevated levels of tau, another type of protein responsible for “tangles” in the brains of Alzheimer’s patients. Those with elevated levels of amyloid plaques who performed poorly on the banking task tended to have higher levels of tau as well, though more so in a different area of the brain. These two tasks were the most complex of the three, according to researchers.

“Mild changes in daily functioning can occur much earlier than typically expected in older adults at risk for Alzheimer’s disease, even before significant cognitive impairment sets in,” Dr. Gad Marshall—associate professor of neurology at Harvard Medical School, director of clinical trials at the Brigham and Women’s Hospital’s Center for Alzheimer Research and Treatment in Boston, and one of the study’s authors—told Fortune in an email.

Detecting such changes early is crucial in order to prepare early Alzheimer’s patients and their caregivers for the reality of the disease, the authors wrote.

Screening for Alzheimer’s disease

The Harvard Automated Phone Task isn’t available to the general public. It’s a “sensitive measure for early changes in daily functioning in individuals at risk for Alzheimer’s disease,” according to Marshall. That means it wouldn’t be helpful to everyone.

There are, however, general screening tools for those concerned they or a loved one may be developing Alzheimer’s disease, he added. The Alzheimer’s Association recommends a number of tools, like the Mini-Cog, that can be used by general practitioners and other health care professionals concerned that patients may be showing early signs of dementia. Some screeners involve caretakers answering questions about their loved one’s functioning.

The Harvard Automated Phone Task may do a better job at detecting early signs of Alzheimer’s disease than typical screeners that rely on subjective input from patients and caregivers, the authors asserted in a paper published last month in the Journal of Alzheimer’s Disease.

“We showed that in older adults with normal cognitive function, difficulties in performing these tasks related to the hallmarks of Alzheimer’s disease pathology (amyloid and tau visualized on PET scans),” Marshall told Fortune.

Signs of Alzheimer’s disease

Those who are concerned they or a loved one might have Alzheimer’s or another form of dementia should talk to their doctor, who may recommend they see another specialist, like a neuropsychologist or a neurologist.

Warning signs of the condition, according to the AARP, include:

• Difficulty performing daily tasks like keeping track of bills and following a recipe while cooking
• Repetition, such as asking the same question over and over and telling the same story multiple times
• Struggling to find the right word
• Getting lost
• Personality changes, such as becoming more anxious, confused, afraid, or paranoid
• Confusion about time and place, especially if someone can’t remember where they are or how they got there
• Misplacing items in unusual areas
• Trouble with hygiene
• Trouble with handling money
• Sudden loss of things one is usually interested in, including family, friends, work, and social events
• Forgetting old memories