A study of patients with amnesia finds that the emotion tied to a memory lingers in the mind even after the memory is gone.
The finding, published this week in the journal PNAS, Proceedings Of The National Academy Of Sciences could have important implications for people with Alzheimer's disease and their families.
One of the loneliest things about loving someone with early Alzheimer's is the feeling that any good times the two of you share just don't matter.
"So often I'll listen to family members say, 'Oh, I don't go and visit Grandpa anymore because 10 minutes after I leave, he doesn't even remember I came,' " says Justin Feinstein, a graduate student in neuropsychology at the University of Iowa.
Feinstein had a hunch that those visits made more of an impression than anyone realized. To check, he turned to several people who, like Alzheimer's patients, have damage to a spot in the brain called the hippocampus.
He describes it as a "kind of a sea-horse-shaped structure right in the middle of the brain, no bigger than the pinkie."
Damage your hippocampus, and you can't hang onto new memories for more than a few minutes. It can happen through a stroke, epilepsy or Alzheimer's disease.
Feinstein says, "Your brain is no longer able to catch onto those experiences, so your day-to-day experiences, like what you had for breakfast this morning, what you did last Saturday night, those are gone. They're vanished."
But Feinstein suspected that the good feelings and bad feelings triggered by meaningful events might linger, captured by a different part of the brain.
So, to stir up some strong emotion, he threw a mini-film fest in his clinic. He showed several people who have damage to the hippocampus a string of short movie clips from tear-jerker classics.
One was the scene in Forrest Gump where he is crying all alone at the grave of his dead wife, Jenny.
It worked. Everyone who watched the film clips was visibly moved — some to tears. Yet a half-hour later, when quizzed about the movies, they didn't remember a thing — not even one woman who had sobbed during the films.
"We test her memory, her memory's gone," Feinstein says. "What happens to her emotions? Well, it turns out she's still sad."
She's extremely sad, she tells the psychologist, though she has no idea why.
"Is it the sort of tightness in the gut or in the throat, or the face, somehow cuing her into the fact that she's sad?" Feinstein asks. "Is it some sort of nonverbal image resonating in her mind, a sort of gloomy image of despair? We don't know. It's an excellent question and one that needs to be followed up on."
Now here's the good news: When Feinstein and his colleagues repeated the experiment, this time showing the same people clips from funny or uplifting movies, like When Harry Met Sally or a Bill Cosby special, it put everybody in a great mood.
And that good feeling outlasted their memories, too. Remember that, Feinstein says, next time you spend time with a friend or family member with Alzheimer's.
"Telling them a simple joke, calling them up on the phone, giving them a visit, could actually have these enormous positive benefits," he adds.
Donna Schempp, a social worker with the Family Caregiver Alliance in San Francisco, says Feinstein's research rings true to her own experience.
Schempp's father, who was once an avid gardner, had Alzheimer's. She learned with him that spending brief visits outside looking at daffodils and tulips paid off for both of them, even after he no longer remembered who she was, or when he'd last seen her.
"The thing is that you're going to visit more if you can find a way to make that event pleasant for yourself," Schempp says, "wheareas, if it's really painful, you're going to avoid it."
Keep your visits short, she says — short but sweet.