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Abstract

On average, humans will develop and retain a steady number of neural connections throughout lifespan. However, as we age our overall number of neurons decreases; therefore, requiring us to share aever-declining resource of neural connections [1]. It has been observed that these connections tend to realign or redistribute as a means of both normal aging and brain pathology. This rewiring of new neural pathway's functions to provide for new learning of common activities of daily living and other important communication and motor skills, and has been observed via positron emission tomography (PET) scans in acute practice of verbal and motor tasks in normal adult brains [2]. In normal adults, excitation in brain regions for new learning is observed in a secondary network consisting of the prefrontal cortex and anterior cingulate cortex as well as other areas specific to the task. This secondary network of neural connections is dubbed the scaffolding areas and is important for the learning of a new motor skill for all ages. Contemporary View of Compensatory Mechanisms in Cognitive AgingThe Scaffolding Theory of Aging and Cognition (STAC) states that as a compensatory mechanism neural excitability, seen as new brain circuit pathways in the areas outside of the primary network, will act to compensate the decrease in available neurons. This may be due to a decrease in total brain volume, specifically white matter, overall structural integrity as a function of age or pathology, or decreased number of dopaminergic pathways [3]. STAC suggests neural pathway activation changes may be permanent changes that are a result of overused or underused areas of the brain, but the scaffolding areas of the brain could be trained or reprogrammed to be more efficient. Interventional training may help transfer the execution of simple skills back to the default primary networks, or optimize the scaffolding areas of the brain to function as proficiently as the default. Upon revisiting their theory five years later, Park and colleagues added the inclusion of "life-course factors" such as experience, genetics and environmental influence that may be variables that affect the early onset of the use scaffolding areas to complete simple skills [4].Although it is recognized that compensatory neural networks assist with the computations performed by the primary or default network, the required use of compensatory networks in older adults has been observed to be less efficient than primary networks used by young adults that do the same task. A few relevant questions remain unanswered concerning this topic-What exactly causes these neural adaptations? Are they entirely detrimental? And what can be done to prevent any cognitive decline that may be associated with these age-related adaptations? Currently, researchers aim to detect if starting interventions at middle age or later adulthood are beneficial to optimize the scaffolding effect on the secondary networks to make them more efficient. Known Contributing Factors on Cognitive PerformanceEmerging ...