New Research Suggests People with Dementia Retain Negative Emotions for Long Time
I first began noticing that Mom was experiencing memory loss in 2002. During that year, my parents came to visit me and I remember Dad telling me that Mom had a simmering anger toward him. Over the years, that anger seemed to get hotter as Mom’s short-term memory got weaker. By the time Mom was finally diagnosed with Alzheimer’s in 2005, her anger and distrust toward my father was palpable, even though there really wasn’t any basis in Dad’s actions for many of these feelings.
So it doesn’t surprise me that a new study by University of Iowa researchers recently published in the Proceedings of the National Academy of Science found that people with impaired memories may retain whatever emotion they experience long after the event has passed and after they have forgotten the incident.
Scientific American.com reporter Katherine Harmon wrote that the findings “are some of the first to investigate the persistence of emotion after memory of the triggering incident has faded and reveal a need for more research about how people with faulty memories, such as the growing number of people with Alzheimer’s disease, process and conserve emotions.”
The researchers analyzed five patients who had damaged hippocampuses, which resulted in severe amnesia. The patients’ condition was similar to what would be experienced with Alzheimer’s and other forms of dementia. After surveying the patients’ emotional states, the researchers showed the group a series of film clips of sad movie scenes. The patients were surveyed again right after seeing the film clips and then again 20-30 minutes after the film clips had ended. On another day, the researchers repeated the research protocol using films with happy scenes.
The scientists “found that even after memory tests (given five to 10 minutes after the film clips ended), the amnesic subjects remembered little—if any—of the details of what they had just seen, but retained the overall emotion for 20 to 30 minutes afterward,” Harmon reported. Additionally, the researchers found that after watching the happy scenes, memory-impaired individuals felt happy for about as long as members in a control group, but their sadness lasted longer.
Lead researcher Dr. Justin Feinstein and his team reported these findings “challenge the idea that by minimizing a specific memory of past trauma, associated sadness will also decrease,” Harmon stated. The researchers noted that some patients reported continually searching mentally for a cause of their sadness after the memory of the film had faded. Thus, the erasure of these sad memories may actually prolong the patients’ feelings of distress.
Dad and I spoke yesterday about this study and it seemed to make sense to both of us in relation to Mom’s experiences. We both feel that Mom got angry over some of Dad’s actions in those early years when she was experiencing memory loss. However, she probably forgot what she was mad about, although she remembered her feelings of anger. I found that when Mom moved to a nursing home near me, it took many months for Mom’s anger toward Dad to fade. That was accomplished because she wasn’t seeing Dad on a regular basis since Dad had gone back to the city where they had lived to pack up their house. Although he visited periodically, it wasn’t until a year later that Dad moved down to where Mom and I lived. By that time, Mom had forgotten her angry emotions and was able to interact pleasantly with Dad again.