Media release
From: PLOSPlaying an instrument may protect against cognitive aging
Older musicians show youthful pattern of brain activity during speech perception
Long-term musical training may mitigate the age-related decline in speech perception by enhancing cognitive reserve, according to a study published July 15th in the open-access journal PLOS Biology by Claude Alain from the Baycrest Academy for Research and Education, Canada, and Yi Du from the Chinese Academy of Sciences.
Normal aging is typically associated with declines in sensory and cognitive functions. These age-related changes in perception and cognition are often accompanied by increased neural activity and functional connectivity – the statistical dependence of activity between different brain regions – in widely distributed neural networks. The recruitment of neural activity and strengthening of functional connectivity are thought to reflect a compensatory strategy employed by older adults to maintain optimal cognitive performance.
Positive lifestyle choices, such as musical training, higher levels of education, and bilingualism, contribute to cognitive and brain reserve, which represents the accumulation of cognitive and neural resources before the onset of age-related brain changes. Cognitive Reserve Theory suggests that this reserve accrued through experience and training can help mitigate the impact of age-related brain decline, leading to better-than-expected cognitive performance. Yet how cumulative reserves influenced by positive lifestyle factors affect neural activity in older populations remains controversial.
To investigate this question, the researchers used functional magnetic resonance imaging (fMRI) to measure brain activity in 25 older musicians, 25 older non-musicians, and 24 young non-musicians who were asked to identify syllables masked by noise sounds. The researchers focused their analysis on neural responses within the auditory dorsal stream, which includes auditory, inferior parietal, dorsal frontal motor, and frontal motor areas, supporting sound-to-action mapping and sensorimotor integration during speech processing.
As predicted, the results revealed reduced age-related declines in speech-in-noise performance among older musicians compared to older non-musicians. During speech-in-noise perception, the older non-musicians showed the typical age-related compensatory increase in functional connectivity in auditory dorsal streams bilaterally (i.e., in both hemispheres of the brain). By contrast, older musicians exhibited a connectivity pattern in bilateral auditory dorsal streams that resembled young non-musicians, with connectivity strength in the right dorsal stream correlating with speech-in-noise perception. In addition, older musicians exhibited more youth-like spatial pattern of functional connectivity during the task, whereas older non-musicians consistently showed a spatial pattern that deviated from young non-musicians.
Taken together, these findings support the “Hold-Back Upregulation” hypothesis, which posits that cognitive reserve from musical training promotes a more youthful functional connectivity pattern, leading to superior behavioral outcomes. Beyond merely compensating for age-related declines, cognitive reserve may work by maintaining the integrity and functional architecture of neural networks, thereby mitigating the adverse effects of aging on cognitive performance. But due to the study design, it was not possible to determine cause-and-effect relationships between musical training and performance in the perception task.
According to the authors, future studies should further test the “Hold-Back Upregulation” hypothesis using different cognitive tasks, such as memory and attention tasks, and investigate other sources of reserve, such as physical exercise and bilingualism. Eventually, these findings may inform interventions aimed at preserving cognitive function and improving communication outcomes in aging populations.
Dr. Lei Zhang adds, “A positive lifestyle helps older adults cope better with cognitive ageing, and it is never too late to take up, and stick with, a rewarding hobby such as learning an instrument.”
Dr. Yi Du adds, “Just like a well-tuned instrument doesn’t need to be played louder to be heard, the brains of older musicians stay finely tuned thanks to years of training. Our study shows that this musical experience builds cognitive reserve, helping their brains avoid the usual age-related overexertion when trying to understand speech in noisy places.”
