Virtual Reality Can Help Us Understand What Arouses Sex Offenders

Seeking to understand why sex offenders commit acts of violence is a strangely archaic undertaking. Researchers often present visual stimuli in the form of photos and audio tapes and measure the offender's responses with a ring around their dick that detects the amount of enlargement. As you might imagine, it's a hotly debated practice.

Penile plethysmography, or PPG, as the test is known, has been criticized for being easily beaten by offenders who merely have to look away from the stimuli. The stimulus itself is usually somewhat abstracted from reality and may not provide adequate arousal levels, or simply not the right kind of arousal.

Taking the procedure into virtual reality could change this, according to forensic psychiatrists at the University of Montreal who built a virtual reality chamber at the Philippe-Pinel Institute, a mental hospital for the criminally insane, to assess offenders as part of their treatment and study what sets them off.

"With our work, we have improved the validity of the stimuli. They are closer to reality than audio, they're also dynamic," Massil Benbouriche, one of the researchers, wrote me in an email. "And to control for the strategies used, we have an eye-tracking device. With that we are able to know when and where our patient is looking. So we can improve our understanding of his information processing (on which cues his decision or reaction is based) and improve the validity of the assessment."

The chamber is a cave-style virtual reality cube, wherein realistic renderings of various environments are projected in 3D on every wall, constituting an immersive space. As various avatars designed to look anywhere from 6 to 25 years old amble across the environment, the offender then puts on a pair of 3D glasses to get the full effect.

By hooking the person inside the chamber up to myriad sensors—eye-tracking, skin conductance, heart rate monitors, and even electroencephalographic brainwave monitoring—the University of Montreal researchers hope to get a better picture of what offenders are thinking and feeling when they decide to assault someone. Oh, and the dick ring is there, too.

According to Benbouriche, a virtual reality approach to investigating the psychology of sex offenders could be beneficial when it comes to understanding how offenders self-regulate in complex and triggering locales. Testing someone's response to stimulus in a controlled lab environment isn't the most realistic approach, after all.

"It's one thing to believe to be able to manage your anger but it's another to do so when you are in a bar, drunk, with a guy who is pushing your buttons, etc.," Benbouriche wrote. "The aim of our work will be to be able to assess not only the risk factor but how it unfolds in a given context. We are not there yet; but we are closer today than yesterday."

For all of the approach's sensational tassels—sex offenders! dick rings!—it's really not so different from how virtual reality is being used in other disciplines. Virtual reality therapies for phobias and drug addictions are making use of the technology's realistic environments to present patients with stimuli accurate enough to trigger them. Hell, even heroin addiction is being tackled by researchers using virtual reality.

The technology has plenty of uses outside of testing sexual offenders. "Sexual offending is just one area of forensic psychiatry," Benbouriche wrote. "We are currently working on the use of virtual reality to deal with auditory hallucinations in schizophrenia […] as well as a brain-computer interface to deal with empathetic deficits."

Benbouriche noted that the eventual goal is to make virtual reality accessible enough for the average researcher to make use of in their routine investigations. Even though a full on virtual reality cave might be out of reach for most researchers, an Oculus Rift headset costs just a couple hundred dollars, and cheaper alternatives are already popping up. To this end, the University of Montreal researchers will be developing virtual reality apps to study the psychology of violence.