Virtual-Reality Therapy for Some People

VIRTUAL- REALITY THERAPY Patients can get relief from pain or overcome their phobias by immersing themselves in computer-generated worlds BY HUNTER G. HOFFMAN

BURN PATIENT participates in a virtual-reality program to relieve the pain of his wound care at Harborview Burn Center in Seattle (above). Wearing a headset and manipulating a joystick, the patient maneuvers through the program called SnowWorld (right), which was specifically designed to ease the pain of burn victims. Studies show that virtual-reality programs are more effective than ordinary video games in distracting patients from the often excruciating pain of wound care.

58 SCIENTIFIC AMERICAN AUGUST 2004 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. n the science-fiction thriller The Matrix, the heroes “plugged in” cannot control the pain. to a virtual world. While their bodies rested in reclining chairs, The patient’s healing skin must be stretched to their minds fought martial-arts battles, dodged bullets and preserve its elasticity, to reduce muscle atrophy and to drove motorcycles in an elaborately constructed software prevent the need for further skin grafts. At these times, program. This cardinal virtue of virtual reality—the ability most patients—and especially children—would love to trans- Ito give users the sense that they are “somewhere else”—can port their minds somewhere else while doctors and nurses treat be of great value in a medical setting. Researchers are find- their wounds. Working with the staff at Harborview Burn Center in ing that some of the best applications of the software focus Seattle, Patterson and I set out in 1996 to determine whether immersive on therapy rather than entertainment. In essence, virtual virtual-reality techniques could be used to distract patients from their pain. The reality can ease pain, both physical and psychological. team members include Sam R. Sharar, Mark Jensen and Rob Sweet of the Uni- For the past several years, I have tual Reality Medical Center, a chain of versity of Washington School of Medi- worked with David R. Patterson, a pain clinics in California, has used similar pro- cine, Gretchen J. Carrougher of Har- expert at the University of Washington grams to successfully treat more than 300 borview Burn Center and Thomas Fur- School of Medicine, to determine whether patients suffering from phobias and anx- ness of the University of Washington severely burned patients, who often face iety disorders. Although researchers must Human Interface Technology Laborato- ) unbearable pain, can relieve their dis- conduct more studies to gauge the effec- ry (HITLab). comfort by engaging in a virtual-reality tiveness of these applications, it seems Pain has a strong psychological com- program during wound treatment. The clear that virtual therapy offers some very ponent. The same incoming pain signal preceding pages results have been so promising that a few real benefits. can be interpreted as more or less painful hospitals are now preparing to explore depending on what the patient is think- the use of virtual reality as a tool for pain SpiderWorld and SnowWorld ing. In addition to influencing the way pa- control. In other projects, my colleagues FEW EXPERIENCES are more intense tients interpret such signals, psychologi- and I are using virtual-reality applications than the pain associated with severe burn cal factors can even influence the amount to help phobic patients overcome their ir- injuries. After surviving the initial trauma, of pain signals allowed to enter the brain’s ); © HUNTER G. HOFFMAN ( rational fear of spiders and to treat post- burn patients must endure a long journey cortex. Neurophysiologists Ronald Mel- traumatic stress disorder (PTSD) in sur- of healing that is often as painful as the zack and Patrick D. Wall developed this SnowWorld

vivors of terrorist attacks. original injury itself. Daily wound care— “gate control” theory of pain in the 1960s ( At least two software companies are the gentle cleaning and removal of dead [see “The Tragedy of Needless Pain,” by already leasing virtual-reality programs tissue to prevent infection—can be so ex- Ronald Melzack; Scientiﬁc American, and equipment to psychologists for pho- cruciating that even the aggressive use of February 1990]. bia treatment in their ofﬁces. And the Vir- opioids (morphine-related analgesics) Introducing a distraction—for example, by having the patient listen to music—

has long been known to help reduce pain University of Washington Overview/Virtual-Reality Therapy for some people. Because virtual reality is ■ One of the best ways to alleviate pain is to introduce a distraction. Because a uniquely effective new form of distrac- virtual reality immerses users in a three-dimensional computer-generated tion, it makes an ideal candidate for pain world, it is uniquely suited to distracting patients from their pain. control. To test this notion, we studied ■ two teenage boys who had suffered gaso- Burn patients undergoing wound care report that their pain drops dramatically ); STEPHEN DAGADAKIS when they engage in virtual-reality programs. Functional magnetic resonance line burns. The ﬁrst patient had a severe imaging shows that virtual reality actually reduces the amount of pain-related burn on his leg; the second had deep burns

activity in the brain. covering one third of his body, including burn patient ■ Virtual-reality programs can also help phobic patients overcome their fear his face, neck, back, arms, hands and legs. of spiders, heights, flying or public speaking. A specially designed program Both had received skin-graft surgery and is now being used to treat post-traumatic stress disorder in survivors staples to hold the grafts in place. of the September 11 attacks. We performed the study during the re-

moval of the staples from the skin grafts. HUNTER G. HOFFMAN (

CHANGES IN BRAIN When healthy volunteers received ACTIVITY IN pain stimuli, functional magnetic RESPONSE TO PAIN resonance imaging showed large increases in activity in several Greatest increase regions of the brain that are known to be involved in the perception of Some increase pain (near right and below). But when the volunteers engaged in a

VIRTUAL REALITY VIRTUAL Some decrease

virtual-reality program during the REALITY VIRTUAL NO stimuli, the pain-related activity Greatest subsided (far right and bottom). decrease NO VIRTUAL REALITY VIRTUAL NO VIRTUAL REALITY VIRTUAL © HUNTER G. HOFFMAN

The boys received their usual opioid med- was the most distracting program avail- legs above the patient’s bed so that he ication before treatment. In addition, able at the time and because we knew it could actually feel the virtual spider. each teenager spent part of the treatment would not induce nausea. Wearing a Both teenagers reported severe to ex- session immersed in a virtual-reality pro- stereoscopic, position-tracked headset cruciating pain while they were playing

University of Washington; gram and an equal amount of time play- that presented three-dimensional comput- the Nintendo games but noted large ing a popular Nintendo video game (ei- er graphics, the patients experienced the drops in pain while immersed in Spider- ther Wave Race 64, a jet-ski racing game, illusion of wandering through a kitchen, World. (They rated the pain on a zero to or Mario Kart 64, a race-car game). The complete with countertops, a window 100 scale immediately after each treat- virtual-reality program, called Spider- and cabinets that could be opened. An im- ment session.) Although Nintendo can World, had originally been developed as age of a tarantula was set inside the vir- hold a healthy player’s attention for a a tool to overcome spider phobias; we tual kitchen; the illusion was enhanced by long time, the illusion of going inside the

TODD RICHARDS AND ARIC BILLS used it for this investigation because it suspending a furry spider toy with wiggly two-dimensional video game was found

www.sciam.com SCIENTIFIC AMERICAN 61 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. Virtual reality is not just To increase the effec- derWorld and ChocolateWorld. (In Choc- tiveness of the virtual ther- olateWorld, users see a virtual chocolate changing the way patients apy, our team created Snow- bar that is linked through a position sen- World, a program specifical- sor to an actual candy bar; as you eat the interpret incoming ly customized for use with real chocolate bar, bite marks appear on burn patients during wound the virtual bar as well.) The subjects re- pain signals; the programs care. Developed with funding ported that their pain dropped dramati- from Microsoft co-founder Paul cally during the virtual-reality session. actually reduce the G. Allen and the National Insti- What is more, improving the quality tutes of Health, SnowWorld pro- of the virtual-reality system increases the duces the illusion of flying through amount of pain reduction. In another amount of pain-related an icy canyon with a frigid river and study, 39 healthy volunteers received a waterfall, as snowflakes drift down thermal pain stimulus—delivered by an brain activity. [see illustration on pages 58 and 59]. electrically heated element applied to the Because patients often report that they right foot, at a preapproved temperature to be much weaker than the illusion of go- are reliving their original burn experience individually tailored to each participant— ing into virtual reality. A follow-up study during wound care, we designed a glacial for 30 seconds. During this stimulus, 20 involving 12 patients at Harborview Burn landscape to help put out the fire. As pa- of the subjects experienced the fully in- Center confirmed the results: patients us- tients glide through the virtual canyon, teractive version of SnowWorld with a ing traditional pain control (opioids they can shoot snowballs at snowmen, high-quality headset, sound effects and alone) said the pain was more than twice igloos, robots and penguins standing on head tracking. The other 19 subjects saw as severe compared with when they were narrow ice shelves or floating in the riv- a stripped-down program with a low- inside SpiderWorld. er. When hit by a snowball, the snowmen quality, see-through helmet, no sound ef- Why is virtual reality so effective in al- and igloos disappear in a puff of powder, fects, no head tracking and no ability to leviating pain? Human attention has been the penguins flip upside down with a shoot snowballs. We found a significant likened to a spotlight, allowing us to select quack, and the robots collapse into a positive correlation between the potency some information to process and to ignore heap of metal. of the illusion—how strongly the subjects everything else, because there is a limit to More recent research has shown that felt they were immersed in the virtual how many sources of information we can the benefits of virtual-reality therapy are world—and the alleviation of their pain. handle at one time. While a patient is en- not limited to burn patients. We con- gaged in a virtual-reality program, the ducted a study involving 22 healthy vol- Seeing Pain in the Brain spotlight of his or her attention is no unteers, each of whom had a blood pres- OF COURSE, all these studies relied on longer focused on the wound and the pain sure cuff tightly wrapped around one arm the subjective evaluation of the pain by the but drawn into the virtual world. Because for 10 minutes. Every two minutes the patients. As a stricter test of whether vir- less attention is available to process in- subjects rated the pain from the cuff; as tual reality reduces pain, I set out with my coming pain signals, patients often expe- expected, the discomfort rose as the ses- colleagues at the University of Washing- rience dramatic drops in how much pain sion wore on. But during the last two min- ton—including Todd L. Richards, Aric R. they feel and spend much less time think- utes, each of the subjects participated in Bills, Barbara A. Coda and Sam Sharar— ing about their pain during wound care. two brief virtual-reality programs, Spi- to measure pain-related brain activity us- © HUNTER G. HOFFMAN Imprint Interactive Technology LLC; VIRTUAL-REALITY PROGRAM re-creating a bus bombing is designed to and sounds of a bus bombing (three screen shots are shown here), the treat post-traumatic stress disorder in survivors of terrorist attacks in program helps them to process and eventually reduce the debilitating Israel and Spain. By gradually exposing the survivors to realistic images emotions associated with the traumatic event. ARI HOLLANDER

62 SCIENTIFIC AMERICAN AUGUST 2004 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. ing functional magnetic resonance imaging (fMRI). Healthy volunteers underwent a brain scan while receiving brief pain stimulation through an electrically heated element applied to the foot. When the volunteers received the thermal stimuli without the distraction of virtual reality, they reported severe pain intensity and un- pleasantness and spent most of the time thinking about their pain. And, as expected, their fMRI scans showed a large increase in pain-related activity in five regions of the brain that are known to be involved in the perception of pain: the insula, the thalamus, the primary and sec- ondary somatosensory cortex, and the af- fective division of the anterior cingulate cortex [see illustration on page 61]. Creating virtual-reality goggles that could be placed inside the fMRI machine FEAR OF PUBLIC SPEAKING can be treated using a virtual-reality program developed by was a challenge. We had to develop a Virtually Better, a software company based in Decatur, Ga., that leases its programs to fiber-optic headset constructed of non- psychologists and psychiatrists. Ken Graap, the company’s chief executive, practices ferrous, nonconducting materials that a speech in front of a virtual audience, shown on his headset and on the computer monitor. would not be affected by the powerful magnetic fields inside the fMRI tube. But SuperSnowWorld, which will feature life- tual reality can alleviate pain in cerebral the payoff was gratifying: we found that like human avatars that will interact with palsy patients during physical therapy af- when the volunteers engaged in Snow- the patient. SuperSnowWorld will allow ter muscle and tendon surgery. (Aimed at World during the thermal stimuli, the two people to enter the same virtual improving the patient’s ability to walk, pain-related activity in their brains de- world; for example, a burn patient and his this therapy involves exercises to stretch creased significantly (and they also re- mother would be able to see each other’s and strengthen the leg muscles.) Our team ported large reductions in subjective pain avatars and work together to defeat mon- at the University of Washington is ex- ratings). The fMRI results suggest that strous virtual insects and animated sea ploring the clinical use of virtual reality virtual reality is not just changing the creatures rising from the icy river. By max- during a painful urological procedure way patients interpret incoming pain sig- imizing the illusion and interactivity, the called a rigid cystoscopy. And we have nals; the programs actually reduce the program will help patients focus their at- conducted a study showing that virtual amount of pain-related brain activity. tention on the virtual world during par- reality can even relieve the pain and fear Encouraged by our results, two large ticularly long and painful wound care ses- of dental work. regional burn centers—the William Ran- sions. Now being built by Ari Hollander, dolph Hearst Burn Center at New York an affiliate of HITLab, SuperSnowWorld Fighting Fear Weill Cornell Medical Center and will be offered to medical centers free of ANOTHER THERAPEUTIC applica- Shriners Hospital for Children in Galves- charge by the Hearst and Harborview tion of virtual reality is combating pho- ton, Tex.—are both making preparations burn centers. bias by exposing patients to graphic sim- to explore the use of SnowWorld for pain Virtual-reality analgesia also has the ulations of their greatest fears. This form control during wound care for severe potential to reduce patient discomfort of therapy was introduced in the 1990s burns. Furthermore, the Hearst Burn Cen- during other medical procedures. Bruce by Barbara O. Rothbaum of Emory Uni- ter, directed by Roger W. Yurt, is helping Thomas and Emily Steele of the Universi- versity and Larry F. Hodges, now at the to fund the development of a new upgrade, ty of South Australia have found that vir- University of North Carolina at Char- lotte, for treating fear of heights, fear of HUNTER G. HOFFMAN is director of the Virtual Reality Analgesia Research Center at the Uni- flying in airplanes, fear of public speak- versity of Washington Human Interface Technology Laboratory (HITLab) in Seattle. He is ing, and chronic post-traumatic stress also an affiliate faculty member in the departments of radiology and psychology at the Uni- disorder in Vietnam War veterans. Like versity of Washington School of Medicine. He joined the HITLab in 1993 after earning his the pain-control programs, exposure Ph.D. in cognitive psychology at the University of Washington. To maximize the effective- therapy helps to change the way people

THE AUTHOR ness of virtual reality in reducing physical and psychological suffering, he is exploring ways think, behave and interpret information.

ERIK S. LESSER to enhance the illusion of going inside a computer-generated virtual world. Working with Albert Carlin of HIT-

www.sciam.com SCIENTIFIC AMERICAN 63 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. Lab and Azucena Garcia-Palacios of object or situation a little at a time. Bit by brief sound effect from the classic horror Jaume I University in Spain (a HITLab af- bit the fear decreases, and the patient be- movie Psycho. Participants repeat each filiate), our team has shown that virtual- comes more comfortable. In our first ses- task until they report little anxiety. Then reality exposure therapy is very effective sions, the patient sees a virtual tarantula they move on to the next challenge. The for reducing spider phobia. Our first spi- in a virtual kitchen and approaches as final therapy sessions add tactile feed- der-phobia patient, nicknamed Miss close as possible to the arachnid while us- back to the virtual experience: a toy spi- Muffet, had suffered from this anxiety dis- ing a handheld joystick to navigate der with an electromagnetic position sen- order for nearly 20 years and had acquired through the three-dimensional scene. The sor is suspended in front of the patient, a number of obsessive-compulsive behav- goal is to come within arm’s reach of the allowing him or her to feel the furry ob- iors. She routinely fumigated her car with virtual spider. ject while touching the virtual spider with smoke and pesticides to get rid of spiders. During the following sessions, the the cyberhand. Every night she sealed all her bedroom participant wears a glove that tracks the After only 10 one-hour sessions, Miss windows with duct tape after scanning the position of his or her hand, enabling the Muffet’s fear of spiders was greatly re- room for spiders. She searched for the software to create an image of a hand— duced, and her obsessive-compulsive be- arachnids wherever she went and avoided the cyberhand—that can move through haviors also went away. Her success was walkways where she might find one. Af- the virtual kitchen. The patient maneu- unusually dramatic: after treatment, she ter washing her clothes, she immediately vers the cyberhand to touch the virtual was able to hold a live tarantula (which sealed them inside a plastic bag to make spider, which is programmed to respond crawled partway up her arm) for several sure they remained free of spiders. Over by making a brief noise and fleeing a few minutes with little anxiety. In a subse- the years her condition grew worse. inches. The patient then picks up a virtu- quent controlled study of 23 patients di- When her fear made her hesitant to leave al vase with the cyberhand; when the pa- agnosed with clinical phobia, 83 percent home, she finally sought therapy. tient lets go, the vase remains in midair, reported a significant decrease in their Like other kinds of exposure therapy, but an animated spider with wiggling legs fear of spiders. Before treatment, these the virtual-reality treatment involves in- comes out. The spider drifts to the floor patients could not go within 10 feet of a troducing the phobic person to the feared of the virtual kitchen, accompanied by a caged tarantula without high anxiety; af- Seattle Times

SPIDERWORLD is a virtual-reality program designed to help phobic background). To provide tactile feedback, the system tracks the patients overcome their fear of spiders. The patient wears a headset positions of a toy spider (suspended by the author, at left) and the that shows a virtual tarantula (screen shot from program is shown in patient’s hand, allowing her to “touch” the virtual creature. BENJAMIN BENSCHNEIDER

64 SCIENTIFIC AMERICAN AUGUST 2004 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC. Another therapeutic ter the virtual-reality therapy, most of and depression after the vir- them could walk right up to the cage and tual-reality sessions. Other touch its lid with only moderate anxiety. patients traumatized by the application of virtual reality Some patients could even remove the lid. tower attacks are now being Similar programs can be incorporat- treated with virtual-reality ther- is combating phobias by ed into the treatment of a more serious apy at Weill Cornell Medical psychological problem: post-traumatic College and New York Presbyter- exposing patients to stress disorder. The symptoms of PTSD ian Hospital. I am also collaborat- include flashbacks of a traumatic event, ing with a team of researchers led by graphic simulations intense reactions to anything symbolizing Patrice L. (Tamar) Weiss of Haifa or resembling the event, avoidance be- University in Israel and Garcia-Pala- haviors, emotional numbing, and irri- cios to create a virtual-reality treatment of their greatest fears. tability. It is a debilitating disorder that af- for survivors of terrorist bombings who fects the patient’s social life and job per- develop PTSD. determine the value of virtual-reality anal- formance and is much more challenging gesia for burn patients. So far the research to treat than specific phobias. Cognitive Virtual Reality by the Hour has shown that the SnowWorld program behavioral therapy protocols, such as the BECAUSE DOZENS of studies have es- poses little risk and few side effects. Be- prolonged exposure therapy developed tablished the efficacy of virtual-reality cause the patients use SnowWorld in ad- by University of Pennsylvania psycholo- therapy for treating specific phobias, this dition to traditional opioid medication, gist Edna Foa, have a high success rate for is one of the first medical applications to the subjects who see no benefit from vir- patients with PTSD. The exposure thera- make the leap to widespread clinical use. tual reality are essentially no worse off py is thought to work by helping patients Virtually Better, a Decatur, Ga.–based than if they did not try it. Virtual reality process and eventually reduce the emo- company that was co-founded by virtual- may eventually help to reduce reliance on tions associated with the memories of the reality pioneers Hodges and Rothbaum, opioids and allow more aggressive wound traumatic event. The therapist gradually has produced programs designed to treat care and physical therapy, which would exposes the patient to stimuli that activate an array of anxiety disorders, including speed up recovery and cut medical costs. these emotions and teaches the patient fear of heights, fear of flying and fear of The high-quality virtual-reality systems how to manage the unwanted responses. public speaking. The company is leasing its that we recommend for treating extreme Researchers are now exploring wheth- software to psychologists and psychiatrists pain are very expensive, but we are opti- er virtual-reality programs can be used to for $400 a month, allowing therapists to mistic that breakthroughs in display tech- standardize the therapy and improve the administer the treatments in their own of- nologies over the next few years will low- outcome for patients, especially those fices. A Spanish firm called PREVI offers er the cost of the headsets. Furthermore, who do not respond to traditional meth- similar programs. Instead of reclining on patients undergoing less painful proce- ods. JoAnn Difede of Cornell University a couch, patients interactively confront dures, such as dental work, can use cheap- and I developed a virtual-reality exposure their fears by riding in virtual airplanes or er, commercially available systems. (Pho- therapy to treat a young woman who was by standing in front of virtual audiences. bia patients can also use the less expensive at the World Trade Center during the In contrast, more research is needed headsets.) September 11 attacks and later developed to determine whether virtual reality can The illusions produced by these pro- PTSD. During the therapy, the patient put enhance the treatment of PTSD. Scien- grams are nowhere near as sophisticated on a virtual-reality helmet that showed tists have not yet completed any ran- as the world portrayed in the Matrix virtual jets flying over the towers and domized, controlled studies testing the ef- films. Yet virtual reality has matured crashing into them with animated explo- fectiveness of virtual-reality therapy for enough so that it can be used to help peo- sions and sound effects. Although the treating the disorder. But some of the ple control their pain and overcome their progress of the therapy was gradual and leading PTSD experts are beginning to fears and traumatic memories. And as systematic, the scenes presented by the explore the virtues of the technology, and the technology continues to advance, we software in the final sessions were grue- the preliminary results are encouraging. can expect even more remarkable appli- somely realistic, with images of people Large clinical trials are also needed to cations in the years to come. jumping from the burning buildings and the sounds of sirens and screams. These MORE TO EXPLORE stimuli can help patients retrieve memo- Virtual Reality Exposure Therapy for World Trade Center Post-Traumatic Stress Disorder: ries of the event and, with the guidance of A Case Report. JoAnn Difede and Hunter G. Hoffman in CyberPsychology & Behavior, Vol. 5, No. 6, pages 529–535; 2002. Available at www.hitl.washington.edu/people/hunter/wtc.pdf a therapist, lower the discomfort of re- Virtual Reality Technology. Second edition, with CD-ROM. Grigore C. Burdea and Philippe Coiffet. membering what happened. John Wiley & Sons, 2003. Our first patient showed a large and More information about virtual-reality therapy can be found on the Web at www.hitl.washington.edu/ stable reduction in her PTSD symptoms and www.e-therapy.info www.sciam.com SCIENTIFIC AMERICAN 65 COPYRIGHT 2004 SCIENTIFIC AMERICAN, INC.