Neuroplasticity is an umbrella term referring to the various capabilities of your brain to reorganize itself throughout life due to your environment, behavior, and internal experiences. To ensure the survival of the species, the human nervous system evolved to adapt to its environment — based on learning from past experiences. This is true for all organisms with a nervous system.
According to the book Neuroplasticity from The MIT Press Essential Knowledge Series, by Moheb Constandi:
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 ended. It was also believed that we were born with all the brain cells we will ever have, that the brain is incapable of regenerating itself, and therefore any damage or injuries it sustains cannot be fixed.
In fact, nothing could be further from the truth.”
In the 1980s, researchers at The University of California at San Francisco (UCSF) confirmed that the human brain remodels itself following the “Hebbian rule.” Donald Hebb, a Canadian psychologist, first proposed that “Neurons that fire together, wire together” meaning that the brain continually alters itself physically and operationally based on incoming stimuli.
Types of Neuroplasticity
Although the definition of the word “neuroplasticity” is vague without further qualification, there are basically two types of neuroplasticity:
- Functional plasticity: The brain’s ability to move functions from one area of the brain to another area.
- Structural plasticity: The brain’s ability to actually change its physical structure as a result of learning.
Plasticity occurs throughout the brain and can involve many different physical structures, for instance, neurons, synapses, vascular cells, and glial cells.
Your Brain Never Stops Changing
Far from being fixed, your brain is a highly dynamic structure, which undergoes significant change, not only as it develops, but also throughout your entire lifespan. As mentioned above, science used to believe that the brain only changed during certain periods in youth. While it’s true that your brain is much more plastic in the younger years and capacity declines with age, plasticity happens from birth until death.
The human brain reaches about 80 percent of its adult size by two years of age, and growth is nearly complete by age ten. We now know that extensive plastic changes continue to take place in late adolescence and beyond. Harnessing the process of neuroplasticity in adulthood isn’t quite as simple as some of the neuro-hype would have you believe, but it can be accomplished under specific circumstances.
You are not stuck with the brain you were born with or even the one you have right now.
Plasticity Is How All Learning and Memory Happen
Learning and memory are neuroplastic processes in your brain, involving chemical and structural changes. By altering the number or strength of connections between brain cells, information gets written into memory. It’s not really known exactly where or how the recording and recalling of memories happen, but the most popular candidate site for memory storage is the synapse, the space between neurons, where they communicate.
This means that when you repeatedly practice an activity or access a memory, your neural networks are physically shaped accordingly. When you cease a behavior or recalling a specific memory, your brain eventually disconnects the cells no longer in use for that pattern. This can work to your advantage and disadvantage. For example, it’s how bad habits are created. All addiction happens because of neuroplasticity. However, it’s also how you can weaken painful traumatic memories and reduce anxiety and depression.
Plasticity Allows For Amazing Adaptability
Regions that are normally specialized to perform specific functions can switch roles and process other kinds of information.
Plasticity was first demonstrated in an experiment with ferrets, who have identical wiring to the auditory cortex and visual cortex as humans except for one important factor. The basic human wiring exists at birth while ferrets grow the circuit after birth. Scientist interrupted the pathway in the ferrets so that nerves from the eye grew into the auditory cortex. The ferrets were then trained to respond to sounds and lights. They “heard” the lights with parts of the brain that would normally process sound.
In a later experiment, sighted adults were blindfolded 24 hours a day for five days. The subjects spent their time learning Braille and performing various tactile and auditory activities. They had their brains scanned before and at the end of the experiment. In the earlier scans, their auditory cortex showed normal activity upon hearing sounds. As expected, their visual cortices lit up when seeing and their somatosensory cortices buzzed when fingering Braille symbols. After five days of being blindfolded, cortical brain regions that had been dedicated to seeing were now hearing and feeling.
You Encourage or Discourage Neuroplasticity With Your Lifestyle Habits
Neuroplastic change occurs in response to stimuli processed in the brain originating either internally or externally. External stimuli, including things like exercise and cognitive stimulation, enhance the production of neural stem cells and promote the survival of newborn neurons. Internal stimuli originating from your own mind, such as meditation and visualization have also been shown to increase neuroplasticity. Certain types of neuroinflammation, insufficient sleep, and stress and depression have proven to decrease neuroplasticity.
You can support your brain and encourage neuroplasticity through your lifestyle habits as follows:
- Sleep — and lots of it — is absolutely essential for an optimally functioning brain.
- Exercise is fertilizer for your brain and promotes the birth and preservation of new brain cells (neurogenesis).
- Learn how to feed your brain the nutrients it needs to be in top form.
- Make your mental health a priority. Take steps to decrease stress and depression.
As for specific activities you can do, Dr. Michael Merzenich, one of the original researchers confirming plasticity at UCSF and the co-founder of Posit Science Corporation, gives this advice in the article 8 Practical Ways to Keep Your Mind Sharp:
Look for activities that are attentionally demanding and inherently rewarding, and that continuously involve new elements to master. Those types of activities engage brain chemistry that’s beneficial for learning, remembering and mood — by stimulating the production of acetylcholine (when paying attention), norepinephrine (when encountering something new), and dopamine (when feeling rewarded).”
Brain Change Is Specific
The nature of change in your brain is specific to the experience. Experience-dependent changes are usually focal and time-dependant. Plastic change doesn’t typically occur widespread across the brain.
Research has proven that the biggest changes occurring in the brain as a result of learning new skills. For example, in animal studies, research has shown that learning new motor skills yields more dramatic changes in the brain than does the repetition of previously acquired motor movements.
This doesn’t mean that working on existing skills is not beneficial. Repetition is absolutely necessary for neuroplastic alterations to last. Most initial changes are temporary. Your brain first records the change, then determines whether it should make it permanent or not. It only sticks if your brain judges the experience to be novel enough or if the outcome is important enough.
Neuroplastic change is also regionally specific. For example, if you’re learning a skill using your right hand, the changes will be greatest in the areas responsible for that movement. The right and left sides of your body are controlled by the opposite side of your brain. Hence, training with your right hand will make the most changes to the left side of your brain, and vice versa.
Neuroplasticity Is Both Positive and Negative
When you hear about neuroplasticity, it’s usually in conjunction with remarkable, positive brain and life change — almost like science fiction. And like science fiction, it has a dark side. It’s because of neuroplasticity that addictions become ingrained in your brain, valuable skills are lost as your brain ages, and some brain illnesses and conditions show up in humans.
Bad habits and addictions
Forming a habit involves neuroplastic change in your brain. A person desires something because their plastic brain has become sensitized to the substance or experience and craves it. When an urge is satisfied, dopamine, a feel-good neurotransmitter, is released. The same shot of dopamine that gives pleasure is also an essential component of neuroplastic change. Dopamine assists in building neuronal connections that reinforce the habit.
Every time you act in the same way, a specific neuronal pattern is stimulated and strengthened. We know that neurons that fire together wire together. Your brain, wanting to be efficient, takes the path of least resistance each time and a habit — or a full-blown addiction — is born. Fortunately, breaking habits and addictions is accomplished via the same neuroplastic process in reverse
A lot of the ways in which our brain function degrades that we typically think of as part of “just getting old” is really negative neuroplastic change. As people age, they unknowingly contribute to their brain’s decline by not using and challenging it as much.
You’ve got a “use it or lose it” brain. Information rarely accessed and behaviors seldom practiced cause neural pathways to weaken until connections may be completely lost in a process called “synaptic pruning.” In his book, Soft-Wired: How the New Science of Brain Plasticity Can Change Your Life, Dr. Michael Merzenich calls backward neuroplastic change “negative learning”.
Negative learning can happen at any age — especially with technology doing so much brain work for us these days. Using a GPS consistently, staring straight ahead at a screen for hours a day, texting and not talking to people face-to-face, and many more habits of the modern lifestyle can contribute to undesirable brain changes.
It’s also because of neuroplasticity that some of the major brain illnesses and conditions show up in humans. Schizophrenia, bipolar disorder, depression, anxiety, obsessive-compulsive and phobic behaviors, epilepsy, and more occur because of neuroplastic change. For example, depression can develop from neuroplastic changes brought about by many things, such as adverse childhood experiences, life circumstances, trauma, lack of emotional support, and stress.
Fortunately for us, neuroplastic change is reversible. You can improve your brain’s function — through the same neuroplastic processes. It’s possible to overcome a mental health condition by driving a brain back towards normal operation through neuroplastic change. Many studies on brain plasticity have demonstrated that many aspects of your brain power, intelligence, or control – in normal and neurologically impaired individuals – can be improved by intense and appropriately targeted behavioral training.