Effect of aging and neurodegeneration on contextual processing

Background Contextual processing (or context processing; CP) is an integral component of cognition. Contextual processing allows people to manage their thoughts and actions by adjusting to surroundings. The process involves the formation of internal representations of context in relation to the environment, maintenance of information over a period of time, and the updating of mental representations to reflect environmental changes. Each of these functions can be affected by aging and associated brain conditions. Here, we update the current research investigating the impact of aging and neurodegeneration on CP. Method Through searching the PubMed, PsycINFO, and Google Scholar databases, 18 studies that focused on aging, mild cognitive impairment (MCI), Alzheimer’s disease (AD), and Parkinson's disease (PD) impacts on CP were retrieved and reviewed in detail. Result Older adults of normal aging had a delayed onset and reduced amplitude of electrophysiological response to information detection, comparison, and execution. MCI patients demonstrated clear signs of impaired CP compared to normal aging. The only study reporting CP in AD suggested a decreased proactive control in maintaining contextual information, but seemingly intact reactive control. On the other hand, PD without dementia showed limited ability to use contextual information in cognitive and motor processes, exhibiting impaired reactive control. Conclusion Data suggest that accelerated aging and neurodegeneration can further impact the changes in CP with age, providing insights for improving intervention strategies. This study highlights the need for increased attention to research this important but understudied field.