By Janice Baker
UNR researchers are studying how the combination of virtual reality and stimulating the brain could help patients overcome crippling fears by using exposure therapy.
Exposure therapy is a psychological treatment used to make patients confront their fears; they gradually experience the thing they are afraid of over and over and over again until the fear subsides. The same technique has been used for decades, except this time it’s virtual combined with brain stimulation.
Dr. Cynthia Lancaster, of University of Nevada, Reno, is testing using VR to conduct exposure therapy to see if it can help people reduce or completely overcome their phobias. She’s combining the virtual exposure with what’s called Transcranial Direct Stimulation. This process uses an electrode that produces small electrical currents that target and activate a specific part of the brain.
In Lancaster’s study, the medial prefrontal cortex is targeted; applying stimulation to this part of the brain helps fire neurons associated with fear reduction.
Lancaster then places the patient in a scary, but virtual, situation.
“If we boost activity in this area by stimulating it, we are giving that area of the brain a jump start to fire and hopefully promote better fear reduction,” explains Lancaster.
“The particular part of the brain we are stimulating is really important in detecting those errors that the patient is making during predictions,” says Lancaster.
“That’s part of what is going on during exposure therapy. The patient is learning that their predictions [that something bad will happen] are not accurate. By boosting activation in this part of the brain during treatment, we’re hoping to help the brain better detect and encode these prediction errors.”
Once the brain is stimulated, the VR set is placed on the patient’s head where they are exposed to their phobia, in this case with heights. The patient is asked to walk a plank that seems to be suspended high above a cityscape. In reality it’s a piece of wood placed on the floor.
To measure the patient’s progress, the team built in a gaming aspect where they can gain points every time they made it across the plank. The points give the patient a sense of competence and satisfaction.
But, does our brain perceive the virtual environment as real?
When the patient is immersed in the virtual environment, the brain goes through the same process as it normally would when it recognizes objects in the real world, says Dr. Gideon Caplovitz, a neuroscientist at the University of Nevada, Reno.
“The earliest stages of our brain take all of the light that’s coming in and deconstruct it. There are many dimensions in the light, which is then broken down,” says Caplovitz.
“The eye is receiving information in pieces and reconstructing them into a simple object once it hits the brain. Light is impinging on your eyes, hitting the retina which gets transduced into bio electrical signals that propagate through your brain. Those signals convey information about very basic properties of the world.”
Then, says Caplovtiz, certain neurons identify key aspects “such as color, shade, distance and size orientation. The magic happens when the brain puts all the pieces together and comprehends what it’s seeing.”
The brain processes colors and lights from VR, too– but despite the similar process, the brain knows the VR visions aren’t real.
One of the big breakers of VR, is the delayed response you see when moving your head. It could be as little as 75 milliseconds, but that is all it takes for your brain to realize that what it’s seeing isn’t real. This can potentially
remove you from the experience.
Not only that, this very small delay can cause motion sickness.
“Our brains compensate for our everyday movements. When moving around from point A to point B in VR, we realize we are in some weird motorized world and this is disconcerting,” says Caplovitz.
“We have all the machinery in our brains to make sense of this motion and when we don’t have it, it can be disorienting and nauseating.”
During the exposure therapy session, the body still responds with physiological stress as if it were real. In the case of a height phobia, the body still produces adrenaline and fear, even though the brain knows it isn’t real.
Over the decades, exposure therapy has been proven that it’s effective and it works. The patient is being asked to re-engage with the trauma that is producing fear. The therapist helps them confront this fear in a way that is therapeutic which helps them extinguish their fear in a safe environment. With virtual reality, there is more opportunity to easily recreate fearful experience in a more controlled environment where the doses of exposure can be more or less incremental.
Using VR versus in-vivo exposure can be advantageous for both cost and logistics. For example, VR allows therapists to easily take one patient through exposure therapy to spiders, then immerse another patient in a war zone. There is still time to discuss the experience within the one hour session, which makes virtual reality very beneficial and cost-effective for both the therapist and their patient.
Virtual reality is becoming the preference of choice when it comes to exposure therapy. Only 3% of patients refuse VR for exposure therapy compared to in-vivo exposure which is 27% . This finding means that VR is becoming more acceptable in patients. As the technology improves, we will start seeing virtual reality being used on patients to overcome psychological trauma through exposure therapy.