It turns out that you can measure a person’s fear response.And anxiety. And perhaps other emotions. To figure this out, researchers neededto be able to reliably trigger these strong emotions in a setting where theparticipants’ reactions could be observed and measured. The researcher whonailed this particular challenge, Dr. Melis Yilmaz Balban, sees a lot ofpotential in using virtual reality experiences to mitigate anxiety or extreme fearresponses. First, though, she’s exposing participants to VR simulations ofsituations where most humans would, indeed, feel fear or anxiety.
Her breakthrough discovery, though, came from research onmice, who have a reliable response to the fear triggered by an overheadpredator. In the lab, Yilmaz Balbansimulated an overhead predator, a hawk, for example, using a blackdisc that expands in size, as an approaching predator’s shadow would. Her studyof the activity in mouse brains fueled her doctoral and post-doctoral researchinto neurological responses to fear.
It’s also the foundation of a new exploration into fearresponses in humans that could lead to VR experiences that teach people—andallow them to practice—healthy behavioral responses to debilitating fear oranxiety reactions. This behavior-changing VR treatment could help people whosePTSD or extreme anxiety makes it difficult or impossible for them toparticipate in normal daily activities.
VR allows triggering—and addressing—fear response
The project, in its early stages, uses the Huberman Lab atStanford University. The VR experiences include simulationsusing 360-degree photography of climbing 250 feet up a tree,swimming with sharks, being trapped in an elevator, and being attacked by adog. The head of the lab, Dr. Andrew Huberman, collected much of the frighteningfootage himself.
These scary VR experiences provide a way to trigger andmeasure the participants’ response. “The first step is to understand what isthe healthy range [of response] and what is the not healthy fear, objectively,”Yilmaz Balban said. “Nobody has really looked at the baseline: How do humansnormally respond to this kind of thing?”
The project, still in early stages, aims to “createobjective biomarkers of unhealthy fear and anxiety disorders,” she said, bymeasuring skin conductance response, heart rate, respiration, pupil size, andgeneral behavior. Once the range of normal responses is understood, the nextstep would be to work on ways to “bring back those parameters that are ‘off’ tonormal” in people with generalized anxiety disorders.
A lot depends on the stimulus, Yilmaz Balban said. For mice,overhead predators are an obvious, and consistent, fear trigger. Humans tend tobe inconsistent in their responses to most stimuli, but “we have identified onestimulus, which is the heights, where I can say 90 percent of the people have avery reliable skin conductance response to the stimulus. It’s not behavior, butthere is one parameter at least, the skin conductance response, that is verytime-locked to this stimulus,” she said. That means that most people will show,at a minimum, a measurable skin response while looking down from a greatheight—real or virtual. This easily reproducible VR experience offers a“handle” or basis to compare the response of people who have a diagnosedanxiety disorder with those who do not, she said.
“The length of the response is different,” Yilmaz Balbansaid. A normal fear response subsides when the trigger ceases or is removed:You climb down from the tree or finish crossing the plank (or exit the VRexperience); the snarling dog goes away. A pathological response ortrauma-induced reaction lasts longer than the stimulus. Behavior changes too,she said, with “fidgety” participants less able to focus on cognitive games evenafter exiting the VR environment. These are the responses that Yilmaz Balbanultimately hopes to help mitigate with her research.
An opportunity for behavior change
Once Yilmaz Balban has identified an objective range ofmeasurements for healthy and unhealthy fear and anxiety responses, behavioraltherapists could create VR interventions that help participants change theirresponse. Using VR offers two significant advantages:
- VR experiences can be highly personalized. “InVR, you can create any environment. You can tailor the environment to theperson’s needs and then create behavioral choices that are alternative to whatthey normally do, for instance for addiction—and then train people for theother choice, for the better choice,” Yilmaz Balban said.
- VR offers immediacy. “The problem with therapyis that you have an event, you feel bad, you talk, you go out in the realworld—and then it happens again. You have to remember what the therapist saidand … it’s just hard for that to work. The brain doesn’t work like that. Thebrain works in millisecond time scale,” Yilmaz Balban said. In a VRenvironment, the behavioral therapy—the coached, healthy response—can occur atthe moment the fear response is triggered. “We have a precise time where we caninterfere with neural stimulation or even behavioral therapy,” she said.
These qualities create avisceral experience for participants that can feel very real.
Beyond fear
Yilmaz Balban hopes to harness the abilities of VR to studythe neurological responses to other stimuli, moving beyond fear. It could bepossible to create profiles of other emotions, such as excitement, measuringthe same neural and physical responses, such as a skin conductance response,pupil dilation, or heart rate increase, she said. “What we’re trying to do iscreate objective measures around emotion in general or internal states.” She’salso looking at brain activity to find correlating neural activity, which canhelp researchers distinguish fear from excitement. Observable behavior alsoprovides clues as to whether a response is fearful or excited. “A lot goes onin the brain that gives us that feeling,” she said. “There is a neuralcorrelate to everything. The ultimate goal is to understand that.”
