18 Scientific American, February 2019THE SCIENCE
OF HEALTHClaudia Wallis is an award-winning science journalist whose
work has appeared in the New York Times, Time, Fortune and the
New Republic. She was science editor at Time and managing editor
of IY_[dj_ÒY7c[h_YWdC_dZ$Illustration by Celia KrampienThe Promise of
Virtual Reality
rom pain relief to mental health,
is poised to reshape patient care
By Claudia Wallis f ou sti t ink of virtual reality as the province of dystopian sci-
ence fiction and geeky gamers, you had better think again. Faster
than you can say “Ready Player One,” VR is starting to transform
our world, and medicine may well be the first sector where the
impact is profound. Be hav ior al neuroscientist Walter Greenleaf
of Stanford University has been watching this field develop since
the days when VR headsets cost $75,000 and were so heavy, he
remembers counterbalancing them with a brick. Today some
weigh about a pound and cost less than $200. Gaming and enter-
tainment are driving current sales, but Greenleaf predicts that
“the deepest and most significant market will be in clinical care
and in improving health and wellness.”
Even in the early days, when the user entered a laughably low-
resolution world, VR showed great promise. By the mid-1990s re -
search had shown it could distract patients from painful medical
procedures and ease anxiety disorders. One initial success was
SnowWorld, which immersed burn pa tients in a cool, frozen land-
scape where they could lob snowballs at cartoon penguins and
snowmen, temporarily blocking out the real world where nurses
were scrubbing wounds, stretching scar tissue and gingerly chang-ing dressings. A 2011 study with 54 children in burn units found
an up to 44 percent reduction in pain during VR sessions—with
the bonus that these in jured kids said they had “fun.”
Another success came in the wake of 9/11. Psychologist JoAnn
Difede of NewYork-Presbyterian/Weill Cornell Medical Center be -
gan using VR with World Trade Center survivors suffering from
post-traumatic stress disorder (PTSD) and later with soldiers re -
turn ing from Afghanistan and Iraq.
In Difede’s laboratory, I saw the original 9/11 VR program with
its scenes of lower Manhattan and the newer Bravemind system,
which depicts Iraqi and Afghan locales. Developed with De part-
ment of Defense funding by Albert “Skip” Rizzo and Arno Har-
tholt, both at the University of Southern California, Bravemind is
used to treat PTSD at about 100 U.S. sites. The approach is based
on exposure therapy, in which patients mentally revisit the source
of their trauma guided by a therapist who helps them form a more
coherent, less intrusive memory. In VR, patients do not merely re -
imagine the scene, they are immersed in it.
Difede showed me how therapists can customize scenes in
Bravemind to match a patient’s experience. A key stroke can
change the weather, add the sound of gun fire or the call to prayers.
It can detonate a car bomb or ominously empty a marketplace. An
optional menu of odors en ables the patient to sniff gunpowder or
spices through a metal tube. “What you do with exposure therapy
is systematically go over the trauma,” Difede explains. “We’re
teaching the brain to process and organize the memory so that it
can be filed away and no longer intrudes constantly in the
patient’s life.” The results, after nine to 12 gradually intensifying
sessions, can be dramatic. One 2010 study with 20 patients found
that 16 no longer met the criteria for PTSD after VR treatment.
Until recently, large-scale studies of VR have been missing in
action. This is changing fast with the advent of cheaper, portable
systems. Difede, Rizzo and three others just completed a random-
ized controlled trial with nearly 200 PTSD patients. Expected to be
published this year, it may shed light on which patients do best
with this high-tech therapy and which do not. In a study with her
colleague, burn surgeon Abraham Houng, Difede is aiming to
quantify the pain-distraction effects of a successor to SnowWorld
called Bear Blast, a charming VR game in which patients toss balls
at giggly cartoon bears. They will measure whether burn pa tients
need lower doses of intravenous painkillers while playing.
Greenleaf counts at least 20 clinical arenas, ranging from sur-
gical training to stroke rehabilitation to substance abuse where
VR is being applied. It can, for example, help recovering addicts
avoid relapses by practicing “re fus al skills” —turning down drinks
at a virtual bar or heroin at a virtual party. Brain imaging suggests
that such scenes can evoke very real cravings, just as Bravemind
can evoke the heart-racing panic of a PTSD episode. Researchers
foresee a day when VR will help make mental health care cheap-
er and more accessible, including in rural areas.
In a compelling 2017 paper that reviews 25 years of work, Riz-
zo and co-author Sebastian Koenig ask whether clinical VR is
finally “ready for primetime.” If today’s larger studies bear out pre-
vious findings, the answer seems to be an obvious “yes.”© 2019 Scientific American