The finding, published in the journal Scientific Reports, attests to the deep hold that familiar music has on memory and points to the potential of music-based therapies for dementia.
The researchers wanted to find out how fast the brain responds to familiar music and determine the processes in the brain that allow for this response. To that end, the researchers recruited 22 individuals and asked 10 of them to provide five songs that were very familiar to them. The team then chose one of the familiar songs for each participant. They matched this to a tune that was similar in tempo, melody, harmony, vocals and instrumentation.
The 10 volunteers passively listened to 100 snippets that were either familiar, sounded similar to their chosen songs or they had never heard before. The snippets were presented in random order and each lasted less than a second.
To record the brain's response, the researchers used a method of recording the brain's electrical activity called electroencephalography imaging and a technique that measures pupil diameter called pupillometry. Pupil diameter could reveal if the brain is highly active.
The researchers found that the participants' pupil dilation rate quickened within 100 to 300 milliseconds after the familiar and similar-sounding tunes were played, indicating that the brain can recognize music at an instant. Right after the rapid pupil dilation, the part of the brain related to memory lit up. Meanwhile, the authors did not find the same response in the remaining 12 volunteers, who weren't familiar with any of the snippets.
"These findings point to very fast temporal circuitry and are consistent with the deep hold that highly familiar pieces of music have on our memory," added Chait. She noted that understanding how the brain recognizes familiar tunes is useful for music-based therapeutic interventions. Many scientists are looking into the possibility that dementia patients' memory of music is well-preserved even though their memory systems have already failed, according to Chait. (Related: Music Therapy Helps Patients Recover Brain Function Following Stroke.)
"Pinpointing the neural pathway and processes which support music identification may provide a clue to understanding the basis of this phenomena," Chait said.
In November, a former ballerina with Alzheimer's disease went viral after being seen dancing to Peter Tchaikovsky’s Swan Lake. In a video recorded in 2019, the same year she died, Marta Cinta González Saldaña could be seen fluttering her hands like the swan queen, her eyes lighting up.
Saldaña's fascinating reaction might have stemmed in part from the fact that she's hearing familiar music. Dr. Pradeep Mahajan, a regenerative medicine researcher, explained that the words and temporal structure of songs fit together like puzzle pieces that easily get etched in people's memory.
"The more we listen to a song, the more connections are formed in our brain, enabling us to create associations and recollect the entire piece," said Mahajan. Music can also enhance the secretion of "happy" hormones like serotonin and dopamine, which improve people's emotional states, according to Mahajan.
Read more articles about novel treatments for dementia at Dementia.news.