Final answer:
The adage most appropriate to memory function and aging is 'Use it or lose it' as it signifies that continuous mental engagement is crucial to maintaining memory over time, in accord with research that suggests practices like mnemonic devices and mental exercises enhance memory retention.
Step-by-step explanation:
The adage most appropriate to memory function and aging is: a) "Use it or lose it." This saying emphasizes the need to continuously engage one's cognitive abilities to maintain and improve memory function over time. As we age, our cognitive functions can deteriorate if they are not actively used; hence, practices like actively engaging in cognitive tasks, using mnemonic devices, and avoiding reliance on technology for simple memory tasks can help maintain brain fitness. Mental exercises like doing math in your head or remembering facts without resorting to a quick search engine can help strengthen memory. Moreover, the concept of storage decay, where unused information fades over time, further supports the notion encapsulated in the adage "Use it or lose it." To combat this, strategies such as rehearsing information, self-referencing, using mnemonic devices like acronyms and acrostics, and ensuring adequate sleep are essential to enhance memory retention. These strategies are particularly useful as we learn from the findings of Hermann Ebbinghaus's forgetting curve showing how quickly memory can fade without practice.