Monday, September 03, 2018

Transcranial Direct-Current Stimulation and the Point of Sports

Full disclosure:  on a scale of sports-fan tendencies, I am off the scale in the negative direction.  But my almost complete lack of intrinsic interest in sports makes me a somewhat dispassionate observer, I hope, of a phenomenon that engages the attention of billions around the globe, and has its ethical aspects as well.  When technology gets in the mix, you have engineering ethics concerns.  And so that’s why we’re looking today at something called transcranial direct-current stimulation (tDCS) and its increasing use by both professional and amateur athletes.

The technique of tDCS consists of connecting two or more electrodes to your skull and sending a small DC current of a few milliamps through the electrodes, where some of it finds its way to your brain.  Depending on which part of the brain is stimulated, the effects can range from nothing to the triggering of an epileptic fit in susceptible individuals.  Most of the time, though, the effects are subtle and have to be documented through elaborate studies.

According to a report in IEEE Spectrum that appeared in 2016, two young tDCS researchers named Daniel Chao and Brett Wingeier decided to take what they learned from working at a brain-implant company that sold anti-epileptic devices, and turn it into some kind of profitable business.  They experimented with a non-invasive tDCS setup instead of an invasive implant, and found that the area of the brain that seemed to respond most positively to tDCS was the motor cortex, which controls voluntary movements.  They founded a company called Halo Neuroscience, and for the last year or two the firm has been selling a product that looks like an odd kind of headphone with foam spikes pointing inward around the headband.  The spikes are the electrodes, and the Spectrum reporter who tried an early prototype found that using the device enhanced her performance on a simple motion:  curling her biceps on a bicep-curling machine.

The article also raised the question of whether tDCS would be viewed unfavorably by sports-regulating commissions such as the World Anti-Doping Agency (WADA), which is the outfit that tries to police Olympic sports to prevent certain categories of drug-taking and other activities deemed to be unfair. 

The criteria used by the WADA to decide whether a given technology is allowable are as follows:  (1)  Does it have the potential to enhance or enhances sport potential?  (2)  Does the substance or practice represent an actual or potential health risk to the athlete?  (3)  Is it in the spirit of the sport?

By now, Halo and similar tDCS firms have been able to show repeatable positive results when athletes train for their particular sports while wearing tDCS rigs.  The devices are not used during an actual competition, because their usefulness consists in aiding what is sometimes called “muscle memory.”  In stimulating the neurons associated with voluntary movement, tDCS makes it easier to acquire the particular patterns of nerve behavior that makes optimum use of one’s muscles.  Even now the fine details of how tDCS does this are not entirely clear, but a lack of total understanding of a technology has never kept entrepreneurs from selling something that works.  And although the results are not spectacular—increases in performance in the 2 to 5 percent range are typical—these marginal improvements are most valuable to professional athletes looking for that little extra something.

Of course, if tDCS becomes as common as Gatorade and everybody uses it, we’ll be right back where we started, except that the tDCS companies will have a guaranteed market indefinitely into the future. 

The second criterion of the WADA about safety seems not to be much of a concern with tDCS.  The technique itself has been studied with modern techniques for at least forty years, and no one has discovered any notable ill effects that tDCS has on most people, unless there is some underlying condition already present such as epilepsy. 

So if there is any ethical objection to tDCS, it would be based on the third criterion, namely that using it is not in “the spirit of the sport.”  And that’s a rather fuzzy phrase.

There are some things you can imagine that would enhance performance, wouldn’t be dangerous to the athlete, but would definitely be contrary to the spirit of the sport.  For example, if a shot-putter got into the ring and brought a carbide cannon with him (a little device that generates acetylene and then sets it off behind a projectile), and used it to hurl the shot a couple thousand feet, this would clearly not be in the spirit of the sport.  The point of shot-putting is to see how far you can throw the thing, not how far your cannon can throw it.  But once you start banning technological aids, it’s hard to draw the line, because all technology is the same kind of thing, in one sense.  It’s just the degree to which it helps that varies. 

It turns out that the WADA has effectively given tDCS a pass, and its use is spreading among athletes in a wide variety of sports ranging from swimmers to cyclers and beyond.  One practical concern that doesn’t show up explicitly in the WADA criteria is the question of how easy it is to detect a given technology’s use.  Carrying a carbide cannon into a shot-put ring is a fairly obvious thing to do.  But using a tDCS device only in training and not on the field is something that would be almost impossible to detect after the fact, and to detect such use would require continuous supervision by WADA personnel that the agency simply does not have.  I suspect this near-impossibility of detection played a major role in the agency’s decision to allow tDCS.

But that doesn’t answer the question of whether tDCS, or any other advanced technology that makes the body something else than what it was before, is truly in the spirit of any sport.  The answer to that question hinges upon one’s philosophy of what sports is all about.  Is it just a way that humans entertain themselves and others, no different in principle than watching a Star Wars movie?  Or is it a striving toward an ideal, a direct assault on the possible using only what you were born with and can acquire through personal discipline? 

Having no discernable interest in sports myself whatsoever, I’m the wrong person to answer these questions.  But those who care need to think about what sports is really about before simply accepting advanced technologies such as tDCS, because one day you may wake up and realize that the sport you loved has turned into something a lot closer to Star Wars than you may like.

Sources:  The article on Halo Neuroscience’s prototype tDCS headset, “A New Kind of Juice” was written by Eliza Strickland and appeared on pp. 34-40 of the September 2016 print issue of IEEE Spectrum.  An online version of the article can be found at  I also referred to articles on tDCS and sports regulation at and  A news release about Halo equipment being used for the USA cycling team can be found on the company’s website at  I also referred to the Wikipedia article on tDCS.

No comments:

Post a Comment