TORONTO – It has long been known that Alzheimer's patients often retain musical memories, even when the recall of names, faces and places has been lost as the disease unceasingly destroys key areas of the brain.
Now, Canadian researchers believe they know why, thanks to the power of MRI brain scanning.
Toronto scientists enrolled 20 people with early-stage Alzheimer's or mild cognitive impairment in a study to find out what was happening in their brains while they listened to familiar music and a composition they had never heard before while having MRI scans.
When the subjects listened to the previously unknown composition, it lit up a region of the brain known as the temporal lobe, "which is what we would have predicted because that part of the brain gets activated when you listen to anything", said the principal investigator Dr . Corinne Fischer, director of the memory disorders clinic at St. Michael's Hospital.
But when participants listened to familiar music – from a playlist of songs they had chosen going back for at least 20 years – there was a much more extensive pattern of activating several areas of the brain, including those involved with emotions and language processing, movement and memory.
"There has always been a question of why music and the ability to appreciate music is preserved, even in the latest stages of Alzheimer's disease," said Fischer.
"And I think one of the things that tells us is that it may be not so much music as it is that familiar musical aspect and the fact that it activates the parts of the brain that are not usually damaged by Alzheimer's pathology.
"So that's why even though you may not know your name, you may not know your environment, you may still be able to appreciate a song because it activates those areas that are not damaged."
Lead author Michael Thaut, a professor of music and neuroscience at the University of Toronto, said it's common for people in even relatively advanced stages of Alzheimer's to call upon them the melodies and lyrics of their past, as well as the attached autobiographical memories. to the music.
"They remember quite a bit of music," he said, adding that someone might say "Yes, this is Duke Ellington" or "This was my favorite music when I went out with my wife."
"But up to this point, we had no idea what the brain mechanisms are driving these very long-lasting memories."
That's why the researchers are excited about their findings, which were to be presented Wednesday as a "hot topic" at the Society for Neuroscience conference in San Diego.
"This is the first study that we are aware of that has actually studied these types of mechanisms and has come up with some ideas why Alzheimer's brain can keep music much longer than other stuff," said Thaut, who designed the research and analyzed. the data.
"So, I think this is a breakthrough study."
For Colleen Newell, she had long suspected that her memory problems and difficulties with organization were signs of cognitive impairment.
"That's one reason I went into the study," said the 60-year-old guitarist, pianist and songwriter, one of about five professional musicians involved in the research. "Not only did I recognize I was dropping (forgetting) nouns, but that my mother has Alzheimer's.
"She's 80, and she's having a similar memory problem at my age. So, I wanted to have a baseline to see what was going on. "
As part of the research, subjects were asked to listen to their playlist for an hour a day for three weeks, while trying to recall related life events and discussing them with family members or caregivers. They then were cognitively tested and also had their brain scanned again.
"What we found there was improvement in brain functional connectivity, changes in brain activation and also improvements in memory scores, which told us that by exposing the brain to repeatedly on this familiar music, people actually did improve the cognitive, and there was evidence that their brain was also changing, "said Fischer.
Connectivity is a measure of information flow between different brain regions, an important component of neurological function; Enhanced connectivity and the other changes suggest that repeatedly listening to familiar music can give Alzheimer's affected brain a kognitive boost, Thaut said, calling results "stunning."
"So I think we're sitting on something very important."
Fisher said these are preliminary results that need to be replicated in a much larger study, and future research also needs to determine if the beneficial effects of routine listening to the familiar music persist or are transitory.
Still, the researchers hope their findings can be the basis for a targeted form of music therapy, with the goal of potentially slowing down the progression of Alzheimer's disease and possibly other dementias – none of which has effective pharmaceutical treatment or treatment.
"Alzheimer's disease at this point is non-reversible," said Thaut, who suggests people with the condition could mimic the study protocol on their own, by listening to the familiar songs of the past every day and recalling the live events that the music evokes.
"We can not say you will be healthy," he said. "But we can say if you engage in that kind of exercise with your family, your friends, with the caregiver, your spouse, even to go to concerts, just engage your brain in music, from the data we have there will be some kognitive benefit. "
While the research found that non-musicians seemed to make more cognitive gain than those who routinely play instruments, Newell said she hopes to continue the study protocol on her own "will bump me up to keep me going."
"And it also encourages us to listen, just to listen to music," said Newell, a worship leader at the Toronto Anglican Church, whose role includes spiritually based music.
"I guess just incorporating it into my daily life."
– By Sheryl Ubelacker, Canadian Press