Interesting conversation on Public Radio's Marketplace about whether clutch players really exist. Do some players actually perform better under pressure -- make better shots under extreme, last-minute pressure than they would under merely high-pressure conditions?
Listen here for the explanation:
March 22, 2007
The nature and nurture of muscles
Some of the truly fascinating insights into talent and greatness emerge from the realm of human musculature -- how our skeletal muscles are initially formed, the attributes of different muscle fibers, and the different ways muscles can be transformed by activity and training. Reviewing the nature/nurture of muscles is also perhaps the best window into the dynamics of genetic expression. Here's an overview:
The human body contains three basic muscle types:
-- Smooth (involuntary muscles serving the digestive system, blood vessels, airways, etc.)
-- Cardiac (also involuntary; cardiac muscle is self-excitable and designed to function on its own)
-- Skeletal (all voluntary muscles, from eyes to fingers to toes).
This overview concentrates on skeletal muscles -- the muscles we exert direct control over.
What are the basic components of skeletal muscle?
Each skeletal muscle is a bundle of thousands of specialized elongated cells called muscle fibers.
The fibers are fed by tiny, blood-filled capillaries, held together with various kinds of connective tissue, and fired ("innervated") by motor neurons -- one neuron firing 600 or so muscle fibers.
Each individual muscle fiber also contains a string of DNA-containing nuclei positioned just underneath and along the entire length of its membrane. The genetic material constantly instructs each fiber how to react *and adapt* to various circumstances.
There are two basic types of muscle fibers:
--
"Slow-twitch" (type I) fibers are designed to contract for long periods
of time; packed with mitochondria, they are extremely efficient at
converting oxygen to fuel.
----- These fibers enable us to jog, swim, bicycle, and other lengthy activities
-- "Fast-twitch" (type II) fibers contract rapidly and forcefully
for a period of seconds, very quickly using voracious amounts of
(anaerobic) energy, becoming spent and
needing to rest and replenish.
----- These fibers enable us to sprint, jump, lift weights and other short-burst activities.
In musculature, we are not all created equal
Although on average, human beings have about a 50/50 mix of slow and
fast-twitch muscle fibers, some are born with differing proportions.
"The 'average' healthy adult has roughly equal numbers of slow and fast fibers in, say, the quadriceps muscle in the thigh. But as a species, humans show great variation in this regard; we have encountered people with a slow fiber percentage as low as 19 percent and as high as 95 percent in the quadriceps muscle." (Anderson et al, 2000)
As anyone might logically expect from the above description of the fiber types, a higher proportion of one or another can offer certain potential advantages to highly-trained athletes. Elite marathon runners and cyclists benefit from a higher proportion of slow-twitch fibers, for example, while sprinters benefit from a higher proportion of fast-twitch fibers. (Anderson et al, 2000).
These genetic differences, however, must be put into careful context.
First, muscle fiber proportion is only one of many performance factors. On its own, it is not a good predictor of individual performance.
Second, muscles are tremendously adaptive to external stimulus, and are designed to be so. The muscles we are born with are merely default muscles -- ready and waiting to recreated in one or another particular direction by active use.
***
To understand how adaptation is literally built into our muscle DNA, let's look at all the things that happen as a result of training
At any given time, each muscle is adapted to a status quo of activity and exertion -- i.e., each muscle is exactly as big, strong and efficient as it needs to be. When pushed just beyond the ordinary level of exertion, a
number of physiological changes begin to unfold:
1. Neural response.
"The first measurable effect is an increase in the neural drive stimulating muscle contraction. Within just a few days, an untrained individual can achieve measurable strength gains resulting from 'learning' to use the muscle." (NSMRC)
2. Genetic response makes muscle fibers more efficient.
In response to extended (aerobic) exercise -- e.g. jogging -- there is a genetic response in the nucleus of each cell fiber that makes it more efficient and enduring: increasing the number of mitochondria and provoking an increase in surrounding capillaries and the accumulation of fats and carbohydrates. (Wiki)
3. Genetic response makes muscle fibers become stronger and grow in size.
In response to overload/resistance exercise -- e.g. weight lifting -- the DNA responds with instructions that will lead to the strengthening and enlarging [hypertrophy] of each fiber.
"As the muscle continues to receive increased demands...upregulation appears to begin with the ubiquitous second messenger system (including phospholipases, protein kinase C, tyrosine kinase, and others). These, in turn, activate the family of immediate-early genes, including c-fos, c-jun and myc. These genes appear to dictate the contractile protein gene response.
"Finally, the message filters down to alter the pattern of protein expression. It can take as long as two months for actual hypertrophy to begin. The additional contractile proteins appear to be incorporated into existing myofibrils (the chains of sarcomeres within a muscle cell). ...These events appear to occur within each muscle fiber. That is, hypertrophy results primarily from the growth of each muscle cell, rather than an increase in the number of cells." (NSMRC)
4. When training is particularly intense and prolonged, slow-twitch muscle fibers can become transformed into fast-twitch fibers, and vice-versa.
"Adult skeletal muscle shows plasticity and can undergo conversion between different fiber types in response to exercise training or modulation of motoneuron activity." (Wang et al, 2004)
A detailed diagram of gene expression at work in muscle fibers:
Exercise, stretches and other muscle activity (LEFT) interacts with DNA in the nucleus (CENTER, circled in red), which in turns interacts with protein translators to effect changes on the cell and surrounding tissue (RIGHT).
(Source of graphic and detailed explanation of genetic transcription: Rennie et al 2004.)
In summary
While evolution has given humans some variability in muscle types, the much more powerful product is its adaptivity. Muscles are designed to be rebuilt.
"The ability of striated muscle tissue to adapt to changes in activity or in working conditions is extremely high. In some ways it is comparable to the ability of the brain to learn." (Bottinelli and Reggiani, 2006)
March 05, 2007
The Myelin in All of Us
This has been a terrific couple of weeks for anyone wanting to better understand talent -- several smart magazine and newspaper pieces have zeroed in on new, critical data. Daniel Coyle has a solid piece in yesterday's NYTimes Sports Magazine that nicely combines Anders Ericsson's work on "deliberate practice" with some very recent findings about myelin, the fatty insulation around nerve fibers that makes electrical nerve signals more efficient (Ishibashi et al, 2006; Fields, 2006).
Here's the connection:
It is now very well established that persons of great skill in any field have spent many years carefully honing their technique (this includes savants, who, by nature of their disability, are able to focus obsessively and persistently on math or music or art, effectively tuning out distractions). Why does high-level skill take so much time and steady effort to develop? It turns out that this slow, patient persistence is exactly what myelin needs to become a thicker and more efficient insulator. You can't rush that process. "In neurology, myelin is being seen as an epiphany," NIH's Douglas Fields told Coyle. "This is a new dimension that
may help us understand a great deal about how the brain works,
especially about how we gain skills."
Coyle also looks at the current epicenters of great sports training -- the Spartak tennis center in Russia, golfers in South Korea, baseball payers in the Dominican Republic and Venezuela. The common thread, he observes, is an obsessive focus on technique. Each of these places are incubators for deliberate practice. Harnessing the competitive drive comes later (at Spartak, they don't allow students to compete in tournaments for at least three years).
***
Are some people born with more efficient myelin-boosters than others? Maybe so. Maybe, on top of the years and years of persistent development of technique, Anna Kournikova and Tiger Woods and Nicolo Paganini also got lucky in the genetic lottery. But to anyone following the last few years of research, genetic differences seem less and less relevant. Here's why:
1. No one has actually found these much-vaunted genetic differences relating to skill and talent. Maybe they're connected to intelligence, maybe persistence -- but we haven't actually found them yet. Meanwhile, Ericsson, Fields, Dweck, et al have exhaustively documented various external influences.
2. Regardless of what differences we're born with, evidence suggests that:
-- most people do not come remotely close to achieving their genetic potential (Ericsson, Ceci)
-- high-level achievement is simply impossible without hard work and persistence (Ericsson et al)
3. We know from Carol Dweck's definitive research that no one benefits from a mindset that relyies on their "natural" abilities. Students encouraged to rely on their natural gifts stagnate, as do poor-performing students told that they are limited by some disability. Conversely, students of every caliber perform better when they are encouraged to equate hard work with results.
January 17, 2007
How Beckham Bends It (Soccer, Part 1)
Beckham is coming to America, albeit somewhat past his prime. Scientists, meanwhile, are still trying to figure out how he did what he did in his prime. [Check out this YouTube compilation.] How did he bend it like that?
In a Mechanical Engineering article, engineers at Yamagata University and University of Sheffield describe how, in his legendary 2002 goal against Greece, Beckham "accelerated the ball to 80 miles per hour, after hitting it about 8 centimeters to the right of its center with the instep of his right foot. The ball spun counterclockwise at about eight revolutions per second and started swerving to the left. The ball rose into the air as if it would soar over the goal's crossbar. Then it slowed to 40 mph, curved further to the left, and dropped into the top left corner for the goal."
Got that, kids?
After studying a soccer ball in a wind tunnel, the engineers deduced this explanation for Beckham's magic kick: The initial spin creates a subtle leftward movement of the ball, which suddenly becomes a severe leftward movement when the speed of the ball drops below 23 miles per hour. That's because the airflow around the ball suddenly changes character at that speed, with the drag immediately increasing by 150 percent. In an instant, the soaring ball drops and curves, as if willed by an invisible force.
The physics are impressive, but nothing compared to the computations taking place inside Beckham's brain in the instant leading up to the kick. "Their brains must be computing some very detailed trajectory calculations in a few seconds purely from instinct and practice," says University of Sheffield's Matt Carré. "Our computers take a few hours to do the same thing."
So how does Beckham's brain make such computations. Was he born with such skill or did he acquire it? If acquired, how?
A new 901-page book, The Cambridge Handbook of Expertise and Expert Performance, documents several decades of research into answering such questions. After several thousand years of "whoa -- how did he do that?" this book and these researchers mark the first rigorous attempt to understand what makes certain people great at what they do. I'm still digesting this research myself, but a few basic findings leap out of these pages right away:
1. Greatness is highly-specific. The exquisite suite of skills required to cross and curl a soccer ball is one specific set of software instructions working with specially-adapted neural hardware; a ballet dancer uses different software and has a different neural network; a violinist a third.
2. Greatness takes time, and requires thousands upon thousands of hours of practice -- and it has to be just the right kind of practice.
3. While any number (and perhaps nearly all) of us are born with the tools to develop a specific brand of greatness, no one is born with the developed tools. And in no case do they develop on their own. Later on, we'll get into the genetics of greatness, which turns out to be virtually the opposite of what we were taught. Genes don't drive us so much as we drive our genes.
