If you query Google about “rewiring your brain,” its auto-complete function will give you a list of the most popular search terms using that phrase. You can, according to the results of such a search, rewire your brain for love and for happiness, to become more successful at work, and even to find meaning in your life. Scrolling down the search results brings up yet more options: rewire your brain to think positively, cultivate self-confidence, sleep better, and avoid procrastination.

If the Internet is to be believed, you can rewire your brain to improve just about any aspect of your behavior, and so the power to transform your life lies in your ability to consciously change that 1.4-kilogram lump of meat inside your head. But what does "rewiring your brain” actually mean? It refers to the concept of neuroplasticity, a very loosely defined term that simply means some kind of change in the nervous system. Just 50 years ago, the idea that the adult brain can change in any way was heretical.

Researchers accepted that the immature brain is malleable, but also believed that it gradually hardens, like clay poured into a mold, into a permanently fixed structure by the time childhood has ended. It was also believed that we are born with all the brain cells we will ever have, that the brain is incapable of regenerating itself, and, therefore, that age or injuries it sustains cannot be fixed. In fact, nothing could be further from the truth.

The adult brain is not only capable of changing, but it does so continuously throughout life, in response to everything we do and every experience we have. Nervous systems evolved to enable us to adapt to the environment and determine the best course of action in any given situation, based on what has been learned from past experiences. This is the case not just for humans, but for all organisms that have a nervous system. That is to say, nervous systems evolved to change, and so neuroplasticity is an intrinsic and fundamental property of all nervous systems.

The concept of neuroplasticity therefore pervades every branch of brain research, and neuroscientists take it for granted that any experiment they perform will induce some kind of change in the nervous system of the organism they are studying. Different researchers define neuroplasticity in different ways, depending on exactly which aspect of brain and behavior they are studying, and the term is so vague that it has become virtually meaningless when used alone and without any further explanation of exactly what type of plastic changes are taking place. Nevertheless, the idea that we can willfully shape our brains to change ourselves is an attractive one, and so the concept has captured the public imagination. 
By Moheb Costandi