Hearing a blast from our past can stir up vivid, poignant memories of a significant other or a significant event in our lives. Psychologists have evinced that this is a common human experience, but how music triggers mental flashbacks in our heads remained mostly a matter of speculation. Now, a new study reveals that the link between music and memories can be traced to a part of the brain known as the medial prefrontal cortex (MPFC).
Study author Petr Janata, an associate professor of psychology at UC Davis‘ Center for Mind and Brain, says his project was motivated by studies with Alzheimer’s patients showing that the MPFC is relatively spared by the disease compared to other brain regions important for memory, and that patients with substantial memory loss can still recognize and “light up emotionally” to music from their past.
Janata previously tested and confirmed that music evokes a wide range of personal memories and emotions in people – from happy to nostalgic to sad. He also devised a visual tool to map and describe the dynamic shifts of song melodies and chord progressions through time.
“These patterns of movement are like signatures of the songs,” Janata said. “So I have a quantitative description of the song … and then I can ask what parts of the brain are tracking the movement of the music … and ask: Are they following music better for songs that [elicit autobiographical memories] versus songs that aren’t?”
Using MRI, Janata scanned and measured the brain activity of 13 UC Davis undergraduates as they listened to clips of 30 different Billboard Top 100 songs taken from their childhood and teenage years. After each excerpt, the students rated how familiar and enjoyable the song was, and how strongly it triggered personal memories.
Outside the scanner, subjects were further questioned about the content and clarity of memories associated with songs they had flagged as being personally relevant during the listening session.
The surveys showed that the students recognized a rough average of 17 out of the 30 tunes, and associated about 13 of the familiar songs to some degree with personal memories. The more familiar the song, the more pleasant the feelings and the more vivid the memories evoked.
Moreover, Janata found, greater personal responses to the songs correlated with brain activity in the upper part of the MPFC. The scans also showed the same region following the shifts in tone for each song’s musical signature, with higher tracking activity found in subjects who reported stronger personal memories.
These patterns suggest that when responding to familiar and evocative music, the MPFC serves as the main hub that links pieces of an associated memory that are stored in different parts of the brain, Janata explained. The emotions and images that make up the memory are then “stitched together into a mental movie” that plays inside our heads as we reminisce about the past.
“This finding corroborates what we have speculated for some time, and adds to the evidence linking music and autobiographical memory with the prefrontal cortex,” said Catriona Morrison, a psychologist at University of Leeds who was not involved in the study, in an e-mail interview.
Janata next plans to replicate the study in older adults and to document in more detail the emotional responses elicited in Alzheimer’s patients by music from their past.
“It’s not an earth-shattering insight, but I’m hopeful that this type of research can help convince people that doing something as simple as playing music from [Alzheimer’s patients‘] past would be reasonable … [to] try to enrich their lives a little bit,” he said.
Richard Harris, a professor of psychology at Kansas State University who was not involved in the study, said the research related to Alzheimer’s patients is intriguing.
“I have done research on autobiographical memory for music, but this is the first study I have seen looking at brain function in that regard,” Harris said in an e-mail interview. “The proposed application to help Alzheimer’s patients is quite interesting and promising.“
ELAINE HSIA can be reached at email@example.com.