Final answer:
Old age is not necessarily a period of mental decline, even though physical decline continues from middle age.
Step-by-step explanation:
Compared to middle age, old age is NOT a period of mental decline. While it is true that physical declines that started in middle adulthood, including declines in stamina, strength, reflex times, and the senses, continue into old age, and most people become more frail, old age does not necessarily mean a decline in mental capabilities. Despite a decrease in the number of brain cells and a less efficient immune system, changes in cognitive abilities are highly individual, and many older adults remain mentally active and sharp. In fact, with the knowledge and experience accumulated over a lifetime, many older individuals can continue to contribute significantly to society and lead enriching lives.