Posts Tagged ‘brain plasticity’

Reviving Brain Plasticity

Saturday, March 27th, 2010

ucsf-brain-scienceA team from the University of California in San Francisco have revived plasticity in the brains of young mice. The finding provides hope that future therapies may permit the repair of brain circuits after injury or disease.

The team transplanted a specific type of immature neuron from embryonic mice into the visual cortex of young mice – a method that doctors could theoretically use to treat neural circuits disrupted in abnormal fetal or postnatal development, stroke, traumatic brain injury, psychiatric illness and aging.

A naturally occurring signaling chemical (or neurotransmitter) known as GABA creates the conditions for acute plasticity in the visual cortex. The study, published in the journal Science, (Vol. 327. no. 5969, 2010), showed that transplanted embryonic neurons, once producing GABA, could induce plasticity in young mice even after the end of the normal critical period.

“The findings suggest it ultimately might be possible to use inhibitory neuron transplantation, or some factor that is produced by inhibitory neurons, to create a new period of plasticity of limited duration for repairing damaged brains,” says author Sunil P. Gandhi, PhD, postdoctoral fellow in the lab of Michael Stryker, PhD, professor of physiology and a member of the Keck Center for Integrative Neurosciences at UCSF. “It will be important to determine whether transplantation is equally effective in older animals.”

Likewise, “the results raise a fundamental question: how do these cells, as they pass through a specific stage in their development, create these windows of plasticity?” says author Derek G. Southwell, PhD, a student in the lab of Arturo Alvarez-Buylla, PhD, Heather and Melanie Muss Professor of Neurological Surgery and a member of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF.

This or similar processes could also explain why young children can learn with ease (new languages for instance) but not adults.

More information: Science paper: “Cortical Plasticity Induced by Inhibitory Neuron Transplantation”,

Training progress for mere mortals – session 303

Tuesday, January 26th, 2010

A few days ago i broke through the n = 6 barrier with a average n back score of 6.05.

The thing that still fascinates me about this is that I’m still seeing slow continuous improvement in my scores. It hasn’t been easy or rapid but steady and pretty continuous. I have felt and seen the difference that clearer thinking can make in day to day and professional life.

It’s really remarkable to reach a max average n back greater than 6… and now i can do 5′s almost without thinking… that just freaks me out.

I’ve been keeping track of my scores in a spreadsheet which enables me to look back on my progress several different ways: number of training days vs progress, number of training sessions vs progress and calendar time vs progress. I’ve completed 303 sessions along the way over the past 9 months.

The most positive and consistent correlate seems to be number of training days with n=back progress.  The graph correlating calendar days to training progress is fascinating in showing a long plateau around n=5 last summer.

Thanks to all who have posted in this blog for inspiration and motivation to keep going.

The key learning from this, for me, is that continuous if not rapid improvement in your working memory is possible whether you start out as a genius or not. Hard work can pay off just stick with it.  Benefits correlated with improvement in working memory are available to all of us.

Encouraging Appropriate Brain Cell Growth

Sunday, January 17th, 2010

In an interesting story about therapy for those with spinal cord injuries, I saw this nice quote on the importance of appropriate brain training. After explaining that most patients with significant spinal cord trauma suffer more or less permanent neurological deficits, Garrett Riggs, M.D., assistant professor of neurology at the University of Central Florida in Orlando, Fla., said:

“Nerve cells do grow, but the problem is getting them to grow from the right spot and make the right connections.”

Eloquently put. The same can be said for any brain training. It should be constructed so as to stimulate the production of new brain cells and encourage the brain to put these new nerve cells to use in a way that will benefit our cognition.

Here’s the full story.

Exercise That Stimulates Brain Plasticity

Thursday, September 17th, 2009

“This New York Times article about brain change in mice reports that mice who underwent intensive treadmill exercise showed more plastic change than mice who underwent normal treadmill exercise or none.

Reading on the article also has some interesting bits about other studies involving exercise and cognition:

“…fundamental questions remain, like whether exercise must be strenuous to be beneficial. Should it be aerobic? What about weight lifting? And are the cognitive improvements permanent or fleeting?

“Other recent studies provide some preliminary answers. In an experiment published in the journal of the American College of Sports Medicine, 21 students at the University of Illinois were asked to memorize a string of letters and then pick them out from a list flashed at them. Then they were asked to do one of three things for 30 minutes — sit quietly, run on a treadmill or lift weights — before performing the letter test again. After an additional 30-minute cool down, they were tested once more. On subsequent days, … the students were noticeably quicker and more accurate on the retest after they ran compared with the other two options, and they continued to perform better when tested after the cool down.

““It appears that various growth factors must be carried from the periphery of the body into the brain to start a molecular cascade there,” creating new neurons and brain connections, says Henriette van Praag, an investigator in the Laboratory of Neurosciences at the National Institute on Aging. For that to happen, “you need a fairly dramatic change in blood flow,” like the one that occurs when you run or cycle or swim.” van Praag says.

“Jen cautions against assuming human bodies work exactly like those of rats. But there are lessons from his work. “It would be fair to say that any form of regular exercise,” he says, if it is aerobic, “should be able to maintain or even increase our brain functions.””

Working-Memory Not Processing Speed Determines Fluid Intelligence

Monday, December 29th, 2008

As I was researching academic studies related to processing speed (with a view to perhaps including processing speed training in the Brain Fitness program) I discovered this fascinating paper:

A latent variable analysis of working memory capacity, short-term memory capacity, processing speed, and general fluid intelligence

(Andrew R. A. Conway, Nelson Cowan, Michael F. Bunting, David J. Therriault and Scott R. B. Minkoff)

Conway set out to see whether working-memory, short term memory, and processing speed could be correlated to fluid intelligence. He found, somewhat surprisingly, that while working-memory capacity has a very strong correlation to fluid intelligence, neither short term memory nor processing speed has a significant correlation.

Conway discusses the significance of this result at some length. He makes some compelling points:

1. His findings strengthen the argument that working-memory can be equated to fluid intelligence. The more items of information we can hold and manipulate, the better we can arrive at intelligent analyses.

2. When testing the effect of processing speed on intelligence it is important to keep the tasks very simple, to avoid any unintended overlap with working-memory. He cites this as the reason that previous studies found a link between processing speed and fluid intelligence.

3. In young children and aging subjects, processing speed may indeed have an impact on fluid intelligence. This would call for processing speed training for the elderly.

I found Conway’s methodology quite thoughtful and sound. Overall, I’m disuaded from designing exercises that train only processing speed, but instead to continue to focus on working-memory and perhaps include an element of processing speed as a way to provide novelty and reward (a faster working-memory task, perhaps).

Brain Plasticity: Learning to Rethink Drugs

Saturday, December 13th, 2008

An article in MIT’s Technology Review “Making an Old Brain Young: Scientists are developing new ways to manipulate the brain’s normal plasticity” caught my eye this week. From the title I thought this would be a serious review of the medical advances expected from therapies that leverage brain plasticity.

Unfortunately, the article focused entirely on the possibility for developing drugs that exploit plasticity.

I’m not against drugs. Drugs are amazing. One very immediate example in my life: My daughter has congenital hypothyroidism — without synthetic thyroid hormone she would have been severely disabled. The medical world should be evaluating drugs that leverage plasticity. What concerned me about the article was the lack of any mention of reference to non-drug therapies. At the moment such therapies seem to be appearing or surfacing thick and fast and can be used right now, without waiting for the drugs to be developed, tested and approved: The Australian Alzheimer’s Association has endorsed brain training exercises as a non-pharmacalogical mechanism for delaying or preventing the onset of Alzheimer’s symptoms. The most effective therapies for stroke victims leverage plasticity through non-drug therapies (see Drake and Taub). Many learning specialists now work with brain exercises to mitigate or correct learning dysfunctions rather than accommodations. And other research has shown that the generation of new nerve cells in the dentate gyrus helps combat depression — something that can be assisted with exercise and brain exercise…

Surely, if our newfound knowledge of plasticity teaches us anything it teaches us that non-drug therapies can achieve some remarkable results.

Doidge – Part 3 – The Science of Brain Training

Friday, November 21st, 2008
Norman Doidge: The Brain That Changes Itself

Norman Doidge: The Brain That Changes Itself

(This post is adapted from an entry on our sister blog at

In Chapter three of his book, Doidge focuses on the remarkable career and contributions to the understanding of brain science of Michael Merzenich , a scientist driven by the desire to solve real world problems (like understanding autism) and not content to leave the solutions to others. With Merzenich, a practical solution is part of the scientific challenge.

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:

Merzenich: The brain is “like a living creature with an appetite” what we feed it to some extent determines how it thrives. When we engage our brains it matters what we do with them.

Shifting brain maps: By microscopic mapping of the surface of the brain, Merzenich showed 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.)

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.

The role of close attention in plastic change: Merzenich found that repetition alone isn’t enough for plastic change. When monkeys in his research 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 a underpinning tenet to the Brain Fitness Pro training exercise and crops up on the training blog all the time.)

Why children learn so easily… and why adults don’t. Brain-derived neurotrophic factor or BDNF plays a critical role in triggering 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. (Again, these are foundations of the Brain Fitness Pro design.)

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).