Final answer:
Older adults use more brain areas for tasks due to the need for additional executive resources stemming from natural age-related changes. Declines in fluid intelligence affect processing abilities, but active lifestyles can mitigate some cognitive decline.
Step-by-step explanation:
Older adults tend to use more brain areas to solve a given problem than younger adults because they need additional executive resources to perform the same task. As we age, there's a natural decrease in corticostriatal connections, which affects our processing abilities, reasoning, and memory—collectively known as fluid intelligence.
Despite a potential increase in crystallized intelligence, which consists of accumulated knowledge and experience, the efficiency in how new information is processed and manipulated can decline.
Moreover, older adults may experience a reduction in the number of brain cells and the efficiency of their immune system, which can lead to cognitive impairments such as Alzheimer's disease. Studies have shown that older adults who engage in mentally and physically stimulating activities experience less cognitive decline, emphasizing the importance of maintaining an active lifestyle for mental health.
It is not a question of intelligence or IQ; it's about how the aging brain adapts to maintain cognitive functions in light of age-related changes.