The symphony of aging: Music's role in stalling cognitive decline

The human brain is an ever-evolving landscape, continuously adapting and reforming. Its structure and connections shift and morph based on our surroundings and experiences, like mastering a new skill or recovering from a cerebral event such as a stroke. Yet, as we step into the later chapters of life, this dynamic quality, or "brain plasticity," begins to wane. Our brain starts to lose grey matter, the housing of our cherished neurons, a phenomenon known as "brain atrophy."

This gradual shift heralds the onset of cognitive decline. Working memory, a cornerstone of numerous cognitive functions, is often hit hardest. Essentially, working memory is our ability to hold and process information for short periods with a specific purpose in mind - for example, recalling a phone number long enough to jot it down or deciphering a sentence in a foreign language.

A collaborative study conducted by UNIGE, HES-SO Geneva, and EPFL has brought to light that active participation and mindful listening to music could serve as a buffer against the decline of working memory. These musical engagements foster brain plasticity and are linked to an increase in grey matter volume. Notably, the positive effects extended to working memory as well. The study encompassed 132 healthy retirees aged 62 to 78 years. A prerequisite for participation was that they hadn't engaged in more than six months of music lessons throughout their lifetime.

"We wanted people whose brains did not yet show any traces of plasticity linked to musical learning. Indeed, even a brief learning experience in the course of one's life can leave imprints on the brain, which would have biased our results," explains Damien Marie, the study's lead author and research associate at the CIBM Center for Biomedical Imaging, the Faculty of Medicine, and the Interfaculty Center for Affective Sciences (CISA) of UNIGE, and at the Geneva School of Health Sciences.

The participants were divided randomly into two groups, irrespective of their inclination towards learning an instrument. The second group partook in active listening sessions that revolved around recognising instruments and analysing musical attributes across a diverse range of genres. Each session lasted an hour, with an additional half-hour of daily homework assigned to both groups.

"After six months, we found common effects for both interventions. Neuroimaging revealed an increase in grey matter in four brain regions involved in high-level cognitive functioning in all participants, including cerebellum areas involved in working memory. Their performance increased by 6% and this result was directly correlated to the plasticity of the cerebellum," states Clara James, the study's last author, a privat-docent at the Faculty of Psychology and Educational Sciences of UNIGE, and full professor at the Geneva School of Health Sciences. Additionally, the researchers discovered that the caliber of sleep, the quantity of lessons undertaken during the intervention period, and the daily amount of training all contributed positively to the level of enhancement in performance.

However, the study revealed a distinction between the two groups. In the group that practiced piano, the volume of grey matter in the right primary auditory cortex -- a critical region for sound processing, remained unchanged, while it decreased in the group that engaged in active listening. "In addition, a global brain pattern of atrophy was present in all participants. Therefore, we cannot conclude that musical interventions rejuvenate the brain. They only prevent ageing in specific regions," clarifies Damien Marie.

The findings underscore that both practicing and listening to music foster brain plasticity and cognitive reserve. The authors of the study argue that these playful and accessible interventions should be at the forefront of strategies for promoting healthy aging. The team's future endeavours involve assessing the potential of these interventions in individuals with mild cognitive impairment, a stage that sits between normal aging and dementia.