Jean McFee Raichle, 94, is a remarkably cheerful woman. She lives in an assisted living center in Seattle staffed by aides who are warm and nurturing. She exists in the moment, mostly untroubled by her Alzheimer’s disease.
Only once in the past several years has her daughter, Marilyn Raichle, witnessed her become alarmed. That was when Marilyn was having problems at work and called to tell her mother about it.
“She could hear the stress in my voice, and I could feel her becoming anxious,” said Ms. Raichle, 63. “I saw that she was picking up on my emotions, and I just stopped right there.”
Ms. Raichle had stumbled onto a phenomenon experienced by many people with relatives who have Alzheimer’s: emotional contagion. The term refers to the way we sense the emotions of others through their facial expressions, tone of voice or body language, and reflect them without being conscious of doing so.
Babies have this innate ability to catch and mirror the emotions of those around them. And it’s not just humans who share this capacity: other primates, rodents and birds appear to have it, too, according to several scientific studies.
Now, new research published in Proceedings of the National Academy of Sciences finds that emotional contagion is heightened in people with mild cognitive impairment (M.C.I.) and Alzheimer’s. And the greater the level of cognitive deterioration, the more pronounced this emotional mirroring seems to be.
Several explanations may account for the finding, said Virginia Sturm, an assistant professor of neurology at the University of California, San Francisco, and lead author of the report.
As the hippocampus — the brain region that helps modulate emotional responses — atrophies in Alzheimer’s disease, emotional sensitivity may be heightened, she speculated. And the brain network associated with emotional connection and empathy may become more active as pathways involved in memory and internal reflection become impaired.
“These networks may have a reciprocal relationship” that’s not yet understood, Dr. Sturm said.
In their research, the San Francisco researchers asked caregivers, friends or relatives to fill out a questionnaire rating the emotional responsiveness of 62 people with M.C.I. and 64 with Alzheimer’s; 111 people with cognitive concerns served as a control group. Then, all the participants in the study received M.R.I. scans of their brains.
The scans showed that higher levels of emotional contagion were associated with atrophy in the hippocampus and other temporal lobe regions, predominantly on the right side. Those regions are involved in several social and emotional functions, including assessing the trustworthiness and perspectives of other people.
“Degeneration in these regions may make people less adept at identifying the emotions of others in pencil and paper tasks, but they’re still able to maintain emotional reactions and connections via other routes that don’t depend on higher-level cognition,” Dr. Sturm said.
Mary Sano, director of the Alzheimer’s Disease Research Center at Mount Sinai Medical Center in New York City, called the study “fascinating” and said, “We talk so much about the cognitive loss in M.C.I. and Alzheimer’s, but in fact the emotional disturbance is equally problematic.”
Irritability or emotional volatility in people with M.C.I. and Alzheimer’s are common; these may arise because “someone is picking up an emotional cue that they can’t put into a cognitive context and is therefore misunderstood,” Dr. Sano said.
Dr. Dylan Wint, director of education programs at the Cleveland Clinic’s Lou Ruvo Center for Brain Health in Las Vegas, said, “I often tell caregivers that as facts start to fade, feelings and tone of your interactions become more important.”
“A great deal of what our higher-order cognitive function does is inhibit or modulate our lower-level responses,” Dr. Wint continued. “As these higher-order functions fail, there’s less of a dampening effect and our instinctual responses rise to the surface.”
What can caregivers do? Dr. G. Allen Power, a geriatrician in Rochester, talks to groups around the country about this issue. “We have to be very aware of our body language — being centered, present, not being distracted — when we’re with someone with dementia,” he said. “If we’re not, they’ll pick up on it and it will begin to shut them down.”
“If we are calm, we can bring people with dementia to a calm place,” he said. “And if we are anxious, we can amp people up.”
Also, recognizing that people with dementia live in a world suffused with emotion can help caregivers understand the importance of identifying feelings that may underlie a patient’s behavior and respond to those, meeting needs that someone is no longer able to express directly.
If you’re getting frustrated with someone with dementia, try stopping and counting to 10, Dr. Power suggested. Think of a positive quality they have, and focus on that. “Any mind trick you can use to get a place of acceptance and being nonjudgmental makes a difference, because the person you’re caring for will sense that and respond to that,” he said.