Doidge – The Brain That Changes Itself – Brain Software

§ November 21st, 2008 § Filed under brain research § 1 Comment

Norman Doidge: The Brain That Changes Itself

In Chapter three of his book, Doidge focuses on the remarkable career and contributions to the understanding of brain rewiring of Michael Merzenich — the scientist behind Posit Science, producers of several brain training software products.

Merzenich embodies the spirit of the practical scientist. His scientific research is driven by a desire to solve real world problems (like understanding autism) and he’s not content to leave the solutions to others. With Merzenich, a practical solution is part of the scientific challenge.

Merzenich believes that brain exercise may be as useful as drugs in treating even severe brain disorders such as schizophrenia and autism.

I don’t want to simply summarize the chapter since I think it won’t do it justice. This section of the book is a must-read for anyone interested in the science behind brain plasticity, brain training, learning and learning dysfunctions, autism, and brain aging. But I will highlight some of the particularly luminous thoughts:

Doidge quotes Merzenich as saying the brain is “like a living creature with an appetite” what we feed it to some extent determines how it thrives. This is a theme that Doidge picks up on and amplifies in the next chapter, sometimes to the detriment of the analogy. But it is a useful touchstone for remembering why when we engage our brains it matters what we do with them.

Shifting brain maps: Merzenich pioneered the idea of shifting brain maps. By microscopic mapping of the surface of the brain, Merzenich was able to show that the areas of the brain controlling and responding to things like touch shifted over time depending upon what the brain needed to do with them. (Use two fingers together all the time, the brain maps for those two fingers become merged.)

In tackling deafness, Merzenich theorized that the brain could decode signals from a fairly simple cochlear implant. Despite protests from fellow scientists that this was impossible, he went ahead and succeeded. His basic designs are still in use.

Competitive plasticity: The brain is constantly assessing how important it is to allocate space to certain skills and functions. The more we demand of a certain skill (like playing the piano) the more space and brain power it gets. The less we use a certain function or skill, the more it loses its brain real estate to other functions.

(Doidge gets himself into some trouble with this concept. As he reveals in the next chapter, he’s fixated on the idea of bad habits (alcoholism, pornography addiction). He practices in this area as a psychologist. In one revealing paragraph he states without any supporting evidence that “unlearning is a lot harder than learning.” This flies in the face of the rest of his argument which seems to suggest that the brain is indifferent to learning and unlearning when it comes to plasticity. It’s all a matter of use or non-use. Since Doidge’s bias or blind spot here is obvious, it’s possible to read around it, but it does make the information muddier.)

The role of close attention in plastic change: In his experiments with monitoring brain maps in monkeys Merzenich found that repetition alone isn’t enough for plastic change. When monkeys performed tasks repeatedly their brain maps changed, but only if they paid close attention to the task did the changes hold long term. This is, of course, critical to anyone who wants to learn a new skill or work with a brain fitness or brain training program. If we don’t apply close attention, or if the work doesn’t require it, we won’t effect lasting changes in our brains.

Why children learn so easily… and why adults don’t. In 1986, Rita Levi-Montalcini and Stanley Cohen received the Nobel prize for identifying a set of proteins called nerve growth factor or NGF for short. Merzenich honed in on one of these called brain-derived neurotrophic factor or BDNF. BDNF plays a critical role in increasing the speed and effectiveness of brain function. Merzenich also found that it seems to act as a triggering device that controls the brain’s ability to absorb and learn. In children during the critical period of learning the child’s body releases a lot of BDNF, keeping the brain constantly stimulated to absorb new information. Children’s brains are engaged and absorbent throughout this period. But at the end of the critical period, the body releases a whole lot more BDNF, a trigger that effectively shuts down the critical period and puts an end to this process.

It may seem odd that we’re designed to stop learning effortlessly past a certain point, but it would be difficult to function as an adult if we were constantly distracted and unable to determine priorities and accumulate the wisdom of trial and error.

Restimulating plasticity in adults: As Doidge puts it, “We rarely engage in tasks in which we must focus our attention as closely as we did when we were younger.” Merzenich found that the brain’s ability to grow new nerve cells, forge plastic change, and learn new skills wasn’t completely shut off in adults, but required certain conditions to be opened up again. The first condition is highly focused attention. The second is reward or satisfaction, which can come from novelty, pleasure, or a sense of achievement.

In Merzenich’s own words: “Everything that you can see happen in a young brain can happen in an older brain.”

This phase of Merzenich’s career lead him to help found Posit Science, a company that publishes brain training software to help children with learning disabilities and to provide brain training for older people who are losing or don’t want to lose memory function or mental sharpness as they age.

(As I’ve written elsewhere, Posit Science seems to have great products, but they’re unfortunately very expensive, and prohibitively expensive in many situations that could really help people. A full program for an adult costs over $600. That’s why I believe that Brain Fitness Pro should remain affordable, in order to bring these kinds of benefits to those who need them but just don’t have hundreds of dollars to spend.)

Related posts:

Building a Better Brain — in the second case study Doidge focuses on Barbara Arrowsmith Young’s discovery that learning disabilities can be mitigated by training the weaker areas of the brain to be stronger.

Part 2 – Rewiring balance — Doidge explores the incredible contributions of Michael Merzenich (the founder of Posit Science).