IEEE Spectrum September, 2016 - 37

high-tech headPhones: Athletes can play their
workout music through the Halo Sport while the discreet
neurotechnology tucked inside pumps up their brains.

curious about research studies that use tDCS to
treat depression, well, they're happy to provide
information, including detailed charts of electrode
placements.) But the dozen or so companies in this
nascent market are bolder in declaring how their
products make healthy people even better. If you
believe the websites, these devices improve memory,
focus, creativity, and learning. Do you want to be
more socially adept? Better at math? Free of your
cigarette addiction? You get the idea.
"There are tDCS devices that claim to basically
make you a superhero," says Hannah Maslen, a bioethicist who studies brain-intervention technologies
at the University of Oxford's Centre for Neuroethics.
"Some of the claims they make are not even theoretically plausible from a neuroscience point of view."
While tDCS has been studied extensively in carefully controlled lab conditions, it's tough to translate
sensitive neurotechnology into mass-produced consumer gadgets that work without fail for every user,
every time. One of the few independent studies of a
commercial brain-stimulation gadget looked at the
first product from the London-based startup Foc.us.
According to the company's marketing, the device
improved attention and memory to make users better at video games. Yet researchers found exactly the
opposite effect: When subjects used the headset while
performing a memory task, they actually did worse.
Halo Neuroscience, though, appears more legit. Its
cofounders, Daniel Chao and Brett Wingeier, previously worked for NeuroPace, a medical-device company that developed a breakthrough brain implant
for epilepsy patients. In conversation, the cofounders
seem borderline obsessed with their double-blind,
sham-controlled research studies. And they don't
claim their device can do everything. Instead they
make only one claim, although it's a doozy: Halo Sport
will help athletes reach new heights of performance.
On my way to the gym for my Halo tryout, my
mind buzzes with questions. Is this thing for real?
And if it does improve athletic performance, am I
witnessing the dawn of brain doping?
efore my first session with the
device I get a science briefing from
Chao and Wingeier. Befitting a tech
startup, Halo's stylish and airy offices
in downtown San Francisco feature stand-up desks
in an open layout, a kitchen stocked with pistachios,
and cleverly named conference rooms. "Frontal
Cortex" is up front near reception; we convened
in "Hippocampus," tucked away toward the back.

Chao, with both a master's in neuroscience and a medical degree
from Stanford University, covers biology, while Wingeier, who has
a Ph.D. in biomedical engineering, talks tech. The two left their jobs
at NeuroPace in 2013 after U.S. regulators approved the company's
epilepsy implant; with that milestone met, they were ready to start a
new venture. They didn't have a precise plan for a product, but they
expected it would be another medical device. "We never would have
predicted that we'd become a sports-science company," Chao says.
Here's what they knew for sure: They wanted to build a company
based on tDCS. In this brain-hacking technique, anode and cathode
electrodes are placed at certain locations on the scalp to channel
current through targeted brain regions. Interest in the method has
boomed since 2000, when researchers published the first important
studies demonstrating tDCS's effects on humans. Last year, more
than 600 tDCS studies came out. The range of research is staggering, because there are as many potential applications as there are
brain regions to target. Investigators are testing tDCS as a treatment
for disorders such as addiction, ADHD, Alzheimer's, aphasia, and
autism-and that's just the As. In another line of inquiry, scientists
are trying to figure out if tDCS can influence mental processes such
as creativity, morality, learning, and memory.
But while eager scientists are exploring all the things that tDCS
might be able to do, a cadre of skeptics argue that many promising
results won't pan out. One prominent voice belongs to Vincent Walsh,
a professor of cognitive neuroscience at University College London.
He argues that tDCS studies have found only minor effects that he
calls "overhyped," notes that many results have not been replicated,
and worries about positive reporting bias: "I don't think people are
reporting all the experiments that don't work," he says.
Within this complicated context, the Halo guys took a cautious
approach. "In the first year of our operation, we did something very
different from other startups: We didn't think about product," Chao
says. Instead, they made a spreadsheet listing all of the possible brain
targets for tDCS and started experimenting, using a crude prototype
to run tests on more than 1,500 volunteers. They were looking for
stimulation procedures that produced measurable and reliable results.
The standout data came from experiments involving the motor cortex, the brain region that controls voluntary movements. So Chao
and Wingeier asked themselves who would be interested in a product
that could augment activity in that brain region, and the answer was
obvious: athletes. They started working on the Halo, though Chao
says he worried that sports teams wouldn't be ready to embrace
brain stimulation: "That's one of the things that kept me up at night:
What would my first meeting be like with the general manager of a
baseball team? Would I get laughed out of the office?"
The company's decision to target the motor cortex was scientifically sound, says leading tDCS expert Marom Bikson, a professor
of biomedical engineering at the City College of New York. "It's
pretty unequivocal that when you apply tDCS in a certain way, you
change the excitability of the motor cortex," he says, citing papers
that showed clear effects on movement, using metrics such as the
speed of finger tapping. He quickly adds, however, that there's a
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Table of Contents for the Digital Edition of IEEE Spectrum September, 2016