The Brain that Changes Itself Summary

Your brain is not hardwired—it’s plastic. It’s adaptable, capable of change, and constantly evolving.

1. Neuroplasticity: The Brain's Ability to Adapt

The human brain has a stunning capacity to rewire itself, known as neuroplasticity. Once thought to be static after early development, research now shows the brain continually reshapes itself through thought, effort, and experience. This adaptability empowers us to overcome limitations and learn new skills well into adulthood.

One process enabling this adaptability is called "unmasking." When a neural pathway becomes inaccessible, secondary pathways "unmask" themselves and grow stronger through repeated use. This rewiring enables the brain to compensate for lost functions or enhance existing ones. Essentially, the brain is equipped with a backup system that kicks into action when needed.

Cheryl Schiltz's story illustrates this beautifully. After losing her sense of balance due to brain damage, she retrained her brain using a device called an accelerometer. The electrodes on her tongue relayed balance-related stimuli to her brain. Through continuous usage, her brain rerouted the signals, allowing her to regain balance without needing the device.

Examples

• Neural mapping creates alternate pathways in individuals recovering from strokes or brain injuries.
• Schiltz adapted to her loss with a tongue-based device, highlighting the brain's resilience.
• Therapies like constraint-induced movement therapy showcase this phenomenon.

2. Environmental Stimulation Alters Brain Structure

The surroundings we engage in have profound effects on the brain’s physical and functional structure. Stimulating environments encourage brain growth and better networking, while dull environments can stunt development.

Mark Rosenzweig’s experiments with rats revealed that those exposed to enriched surroundings had heavier, healthier brains with a richer blood supply. Prolonged exposure to mental challenges provided the brain with the nutrients and stimuli it needed for improvement. This underscores the value of engaging in thought-provoking activities for cognitive well-being.

Barbara Arrowsmith Young is a remarkable case study in self-imposed environmental stimulation. Despite severe learning disabilities, she designed exercises targeting her specific deficits, such as reading hundreds of clock faces to grasp time concepts. Her unrelenting practice led her to excel in those once-challenging areas.

Examples

• Rats exposed to enriched environments developed more neurotransmitters and brain mass.
• Barbara used mental exercises to improve her comprehension of time and logic.
• The benefits of using stimulating puzzles, music, or language-learning apps reflect this ability.

3. Brain Maps Change with Use

Brain maps, or regions linked to body movements, are fluid and ever-changing. These maps can grow, shrink, or even be reassigned depending on our habits and injuries. Each activity we perform builds pathways, creating a stronger allocation of neural resources to regular actions.

Michael Merzenich’s studies revealed that maps altered in size according to use. Severing certain nerves in monkeys’ hands resulted in the brain maps being repurposed by other functioning nerves. This discovery showed that inactive brain areas were not wasted but instead reassigned.

This adjustment also explains quirky phenomena like foot fetishes, as the sensory brain maps of feet and genitals are closely linked, allowing crossover activity to influence preferences.

Examples

• Monkeys’ brain maps adjusted when key hand nerves were severed.
• People’s sensory maps explain behaviors such as persistent phantom limb pain.
• Actions practiced over years, like playing the violin, lead to expanded dedicated brain maps.

4. Sexuality Is Shaped by Brain Plasticity

Our sexual preferences often reflect the malleability of the brain, shaped by both biology and early life experiences. While our preferences may seem fixed, the brain's ability to change means this is rarely the case.

Regions like the hypothalamus (instinctive behaviors) and amygdala (emotions) are particularly responsive to psychological and situational inputs. These areas develop preferences during childhood but remain susceptible to change throughout life due to new exposures and repeated experiences.

Pornographic habits offer a modern example of the brain's plastic capacity for sexual rewiring. Latent preferences become stimulated and reinforced when dopamine is released during viewing, creating stronger neural connections. Over time, these preferences evolve into distinct sexual behaviors.

Examples

• Childhood interactions influence adult romantic decisions and attraction patterns.
• Exposure to diverse imagery reshapes sexual preferences or strengthens existing ones.
• Dopamine release during repetitive acts helps reinforce specific neural circuits.

5. Brain Exercises Facilitate Recovery from Injuries

Repetitive, focused exercises have the potential to "retrain" the brain and restore lost abilities. Dr. Edward Taub’s constraint-induced movement therapy is a testament to this principle. By limiting active use of functioning limbs, damaged limbs are forced into regaining function.

Dr. Bernstein, an eye surgeon recovering from a stroke, struggled with tasks like buttoning his shirt. Through consistent, simple exercises such as wiping tables and practicing hand movements, he rebuilt his neural pathways. This process allowed him greater independence and functionality.

This approach relies on reshaping behavior incrementally through "shaping" or gradual rewards for small gains. Day-to-day repetition brings lasting changes in mobility and brain structure.

Examples

• Dr. Bernstein recovered motor function despite his stroke through therapy.
• Taub’s experiments with monkeys helped popularize constraint-induced therapy.
• Reward systems boost the likelihood of retraining success in patients.

6. Focusing Attention Can Rewire the Brain

For conditions like OCD, attention and focus become powerful tools for retraining thought patterns. UCLA psychiatrist Jeffrey Schwartz used brain scans to show how OCD patients exhibit malfunctioning caudate nuclei, leaving them trapped in cycles of worry.

By consciously redirecting focus onto purposeful activities, such as helping someone or playing music, new neural pathways are created. These positive behaviors eventually override the older, obsessive circuits, giving patients an empowering tool they can control.

In Schwartz’s method, consistently forming and reinforcing new habits leads to the decay of undesirable behaviors.

Examples

• Redirecting focus through activities, even simple ones, diminishes obsessive habits.
• Schwartz uses brain scans to confirm structural changes during therapy.
• Alternative pleasures like volunteering help patients form healthier circuits.

7. Ghost Limbs: Phantom Suggestions and Pain Solutions

Phantom limb syndrome causes individuals to feel pain in missing limbs, an eerie demonstration of the brain’s insistence on input. The brain’s map adapts to loss, but sometimes maladapts, leading to ongoing discomfort.

V. S. Ramachandran revolutionized treatment with a mirror box, tricking the brain into "seeing" the missing limb. This helped patients "release" pent-up sensations and regain control. Philip Martinez found relief from phantom pain after using the method for just a few weeks.

This discovery reaffirms the importance of using imaginative techniques to rewire persistent brain falsehoods.

Examples

• Phantom limb pain arises from maladapted brain maps.
• Ramachandran’s mirror box provided ground-breaking relief for amputees.
• Brain retraining transformed the outlook of patients like Philip Martinez.

8. Thought Power: Imagining to Enhance Skills and Strength

Imagination has a tangible effect on physical brain structure. Alvaro Pascual-Leone’s tests showed that imagining piano practice produced neural effects similar to actual practice. Visualizing activated motor and sensory areas, leading to improved performance.

Even muscle strength can be improved mentally. Participants imagining finger exercises achieved 22% improvement in strength, compared to 30% in those practicing physically. Visualization mimics real engagement, making it a pragmatic tool.

These findings illustrate that mental training can be as impactful as physical activity for enhancing abilities.

Examples

• Piano players improved equally through mental and physical rehearsal.
• Imagined exercise increased finger strength by nearly 25%.
• Visualization shaped motor skills without needing physical interaction.

9. Stem Cells: The Brain’s Lifelong Potential

Contrary to old beliefs, our neurons are not finite. Neuronal stem cells create new neurons even into old age, replenishing brain areas like the hippocampus (memory) and olfactory bulb (smell).

Activities like learning and exercise further boost neuron production. Additionally, cognitive challenges like dancing or learning an instrument stave off dementia by extending neuron life.

These stem cells defy the aging process, ensuring continued brain renewal and adaptability with the right stimuli.

Examples

• Stem cells ensure neurogenesis in areas such as the hippocampus.
• New environments stimulate sustained brain development.
• Physical activity complements mental exercises to prolong neuron survival.

Takeaways

1. Engage in mentally stimulating activities like learning a language or playing an instrument to keep your brain adaptable.
2. Use visualization and mental practice to enhance skills or make physical recovery more effective.
3. Stay physically active with exercises like walking, dancing, or Tai Chi to promote neuron growth and brain health.