A pleasant emotion can linger
Can feelings trump memory in those with amnesia or dementia? Does your mother remember the emotion she felt when you gave her a flower, even after she has forgotten about the visit herself? Even if she cannot remember exactly who you are? NPR has a report here on a study of patients with amnesia published in PNAS, Proceedings of the National Academy of Sciences.
The study, by brain researchers in Iowa, examined patients with amnesia because of damage to the hippocampus, a structure in the brain that is key to memory retention. (The study, titled “Sustained experience of emotion after loss of memory in patients with amnesia,” by Justin S. Feinstein, Melissa C. Duff, and Daniel Tranel, can be found here.)
“…What would happen to the feeling of an emotion if we could no longer remember the emotion-inducing event?” the authors ask. “Would the feeling fade away in parallel with the vanquished memory? Alternatively, is it possible that the feeling could persist without the memory?”
To answer these questions, the researchers studied five people with severe amnesia due to damage to the hippocampus. Feinstein showed the amnesia patients film clips designed to trigger sadness — one scene, in Sophie’s Choice, showed Meryl Streep’s daughter being ripped away from her arms by a Nazi soldier. Shortly after the film, the amnesia patients could not remember any details about the clips, but their feeling of sadness lingered. Sunny, humorous film clips (Bill Cosby, When Harry Met Sally) induced happiness — for about 17 minutes or so afterward.
The results can just as easily apply to someone with Alzheimer’s. “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,’” Feinstein, a graduate student in neuropsychology at the University of Iowa, told NPR reporter Deborah Franklin. But a happy feeling might linger — reason enough for a visit.
The authors are well aware of the social implications, particularly for dementia patients in nursing homes. “The results of this study have direct implications for how society treats individuals with memory disorders (such as patients with Alzheimer’s disease), as events that have long been forgotten could continue to induce suffering or well-being,” they write.
“For example, a simple visit or telephone call from family members might have a lingering positive influence on a patient’s affective state even though the patient may quickly forget the visit or phone call.” But it can work the other way: “On the other hand, routine neglect from staff at nursing homes may leave the patient feeling sad, frustrated, and lonely (even though the patient can’t remember why).”
In the end, the authors offer a sweeping but common-sense prescription. “As the number of individuals suffering from Alzheimer’s disease and other forms of dementia reaches epidemic proportions, it will be imperative for society to follow a scientifically-informed standard of care for patients with memory impairments. Here we provide clear evidence showing that the reasons for treating amnesic patients with respect and dignity go beyond simple human morals.”
