In this chapter, Doidge introduces us to ninety-year-old Dr. Stanley Karansky. After retiring at 70 years old, Karansky retrained himself to be a family doctor. He worked in a small clinic for 10 years. More recently he completed the brain exercises that Merzenich’s team developed at Posit Science. These exercises improved his driving alertness during daytime and nighttime. At the time of the writing of this chapter, Karansky was still an active ninety-year-old whose parents died in their 40s. Karanasky illustrates how neuroplasticity reaches into the latter years of life.
While Ramon y Cajal tried to find the truth of neuroplasticity for older folks, he failed. His work in the early part of the 20th century helped form the foundation for this discovery. His conclusion in his masterpiece of 1913, Degeneration and Regeneration of the Nervous System was, “In adult (brain) centers the nerve paths are something fixed, ended, immutable. Everything may die, nothing may be regenerated. It is for the science of the future to change, if possible, this harsh decree.” ( p.249)
Beginning in 1965, the work of Joseph Altman and Gopal D. Das of MIT demonstrated that rat brains produced new neurons. At that time, this study did not go with the current conventional wisdom so the results were discounted. Later in the 1980s, Fernando Nottebohm, a bird specialist, examined the brains of birds and came to the same conclusion. Then, Elizabeth Gould of Prince University set out to discover that the same is true in human brains. Eriksson followed with additional proof of regeneration of neurons in human brains.
Frederick “Rusty” Gage and Gerd Kempermann of Salk Laboratories in La Jolla, California determined to find out if neurogenesis strengthens mental capacity by studying mice. Gage’s theory was that “novel environments may trigger neurogenesis.” (p. 252) This theory is consistent with the work of Michael Merzenich.
In addition to this momentous discovery, it is also known that the brain’s “pruning back” when cells die can also improve function. Research also demonstrates that lateralization diminishes during those older years.
Dr. Karansky is doing things that are important to fight off age-related memory loss and physical function by exercising the brain and body. To summarize this Doidge ends the chapter in this way: “when Pablo Casals, the cellist, was ninety-one years old, he was approached by a student who asked, ‘Master, why do you continue to practice?’ Casals replied, “Because I am making progress.’”(p. 257)
What are you doing to maintain body and brain function?