An important challenge in our golden years will be to find
ways to slow age-related declines in motor performance. Recent studies have shown that an older
person demonstrates increased brain activation compared to their younger
counterpart performing the same motor task.
Are the neural mechanisms that drive this 'overactivation' beneficial or
detrimental to performance in an aged population? This Fri., April 4,
Heuninckx, S., Wenderoth, N., & Swinnen, S. P. (2008). Systems neuroplasticity in the aging brain: Recruiting additional neural resources for successful motor performance in elderly persons. Journal of Neuroscience, 28(1), 91-99. (link to pdf of article)
Functional imaging studies have shown that seniors exhibit more elaborate brain activation than younger controls while performing motor tasks. Here, we investigated whether this age-related overactivation reflects compensation or dedifferentiation mechanisms. "Compensation" refers to additional activation that counteracts age-related decline of brain function and supports successful performance, whereas "dedifferentiation" reflects age-related difficulties in recruiting specialized neural mechanisms and is not relevant to task performance. To test these predictions, performance on a complex interlimb coordination task was correlated with brain activation. Findings revealed that coordination resulted in activation of classical motor coordination regions, but also higher-level sensorimotor regions, and frontal regions in the elderly. Interestingly, a positive correlation between activation level in these latter regions and motor performance was observed in the elderly. This performance enhancing additional recruitment is consistent with the compensation hypothesis and characterizes neuroplasticity at the systems level in the aging brain.