If a brain is exercised properly, anyone can grow intelligence, at any age, and potentially by a lot. Or you can just let your brain idle - and watch it slowly, inexorably, go to seed like a sedentary body.

The quote "If a brain is exercised properly, anyone can grow intelligence, at any age, and potentially by a lot. Or you can just let your brain idle - and watch it slowly, inexorably, go to seed like a sedentary body." by Michael Merzenich emphasizes the importance of actively engaging and exercising the brain to maintain and even enhance intelligence over time. Merzenich, a neuroscientist known for his work on brain plasticity, is highlighting the concept of neuroplasticity—the idea that the brain is capable of change and growth throughout a person's life, particularly when it is continuously challenged and stimulated.

Merzenich suggests that just as a sedentary body loses its strength and health when not properly used, a brain left without mental stimulation will become less efficient, potentially leading to cognitive decline. The comparison between a sedentary body and an idle brain reinforces the importance of regular mental exercise, such as learning new skills, problem-solving, and engaging in stimulating activities, to maintain brain function and intellectual capacity.

The quote also challenges the common belief that intelligence is fixed or that it cannot be improved as we age. Instead, Merzenich argues that intelligence is malleable and can be cultivated at any age, provided we make the effort to exercise our brains. This perspective aligns with the growing body of research showing that the brain remains plastic and capable of growth, even into older adulthood, as long as it is given the proper tools and challenges.

In essence, Merzenich’s quote underscores the idea that intelligence is not a static trait but a dynamic ability that can be nurtured through continuous mental activity. By stressing the importance of brain exercise, he encourages individuals to remain intellectually active, to avoid mental complacency, and to recognize that the brain, like the body, requires regular activity to function optimally throughout life.