In games like Crystal Rift, virtual-reality creators are beginning to explore how to harness the medium’s darker side without causing psychological harm. COURTESY PSYTEC

If Kitchen, a five-minute virtual-reality demo created by the Japanese studio Capcom, were a short film, few viewers would be moved to panic by its misery of horror-movie clichés. In the demo, which has been making the rounds at tech conferences in recent months, you begin strapped to a chair in a kitchen, the floor around you lumpy with cadavers. After a few beats, one body groans unexpectedly to its feet and, with an ungainly lunge, attempts to free you from your restraints. Then a lank-haired woman of the kind that, if Japanese cinema is to be believed, routinely climb out of dark wells and staticky television screens steps into view behind your oblivious helper. He promptly rejoins his compatriots on the floor. The woman draws close and, with a whipping motion, stabs a knife deep into your thigh. At the movie theatre, such an attack might draw, at best, a swift wince. In V.R., the terror is more palpable: a phantom pain shoots up your leg.

In the past several years, as the nascent medium of virtual reality has come into its own, scientists and creators have begun to explore its potential effects on the human mind. Some are undoubtedly positive—as, for instance, when the technology is used to help war veterans overcome P.T.S.D., or as a means to expand a person’s capacity for compassion. But the immediacy of V.R. has a dark side, too. Several months ago, Michael Madary and Thomas K. Metzinger, researchers from the Johannes Gutenberg University of Mainz, in Germany, published a series of recommendations on the ethical design and implementation of virtual reality. Their appraisal of the medium’s psychological force is both studious and foreboding. “The power of V.R. to induce particular kinds of emotions could be used deliberately to cause suffering,” they write. “Conceivably, the suffering could be so extreme as to be considered torture.” In filmmaking, the director must perform a kind of seduction of dread, leading viewers through an escalating series of psychological states. In the immersive world of V.R., no such dance is required.

“I’m neither a neurologist nor an anthropologist, but that kind of—I don’t know—that, like, deep-lizard stuff in our brains comes alive in virtual reality,” Scott Stephan, a designer at Wevr, a V.R. studio in Los Angeles, told me recently. In Stephan’s game Anamnesis, you play as a FEMA agent helping to relocate people after a super flu has devastated the city. “The gap between ‘things that happen to my character’ and ‘things that happen to me’ is bridged,” Stephan said. This distinction can transform an experience from merely flinch-inducing to sincerely frightening. “The way I process these scares is not through the eyes of a person using their critical media-viewing faculty but through the eyes of I, the self, with all of the very human, systems-level, subconscious voodoo that comes along with that.” If traditional media—novels, films, radio, even video games—offer the thrill of the roller coaster, the mimicry of peril, V.R. removes the sturdy track and the shoulder restraints. “A book can be put down,” Stephan said. “It’s always clear that the experience is voluntary.” In V.R., he added, there is not even the comforting abstraction of the video-game controller. “Your body becomes profoundly integral. Your body becomes the interface.” In this way, mundane tasks like picking up a cup of coffee or opening a desk drawer—two of the actions on offer in Job Simulator, launched earlier this year—become fascinating. Likewise, fear takes on a new texture. Capcom reports that, after a few minutes with Kitchen, many players tear off their headsets in an attempt to flee the scene.

The spell of virtual reality, though, lingers. Madary and Metzinger point to evidence of “a lasting psychological impact after subjects return to the physical world.” They recommend “careful screening of subjects to minimize the risks of aggravating an existing psychological disorder or an undetected psychiatric vulnerability.” It’s as if moviegoers were asked to receive a clean bill of mental health before being allowed to watch “A Clockwork Orange.” To help manage viewers’ fear, the team at Wevr has implemented a rule not to include any antagonist “bigger than a small dog” in a virtual-reality scenario. “It is a nod to the lizard brain,” Stephan said. “Things that size feel like they can’t hurt you.”

Part of the power of V.R.-based horror comes from the fact that the director knows exactly where the viewer is looking. “With that knowledge, we can play mind tricks or trigger events based on the gaze,” Jon Hibbins, the director of Psytec Games, a London-based V.R. studio, told me. For instance, he said, in Psytec’s most recent fantasy-horror title, Crystal Rift, “a monster can appear in a vent only when the player looks at the vent.” Hibbins claims that, as viewers’ brains are tricked into believing that they are physically present in a reality, the memories they form are much stronger than those made when watching so-called flat-screen media. To soften these memories, Hibbins and his team have introduced a slider into their game that allows players to control the intensity of the horror. “ ‘Normal’ will be an average scare experience,” he said. “You’ll hear voices in the distance, ghosts in the corridors, sound from the voids, and snakes in the corridors. ‘Extreme’ introduces jump scares, such as ghost figures that run through your body. It really does offer everyone an option.”

Since 1966, the year that the Hays production code, which moderated “brutality and possible gruesomeness” onscreen, was reversed, film directors have prodded the boundaries of what is permissible in horror cinema. (See the “Saw” franchise, “Hostel,” and “The Human Centipede.”) These early months of V.R. horror—the Oculus Rift and the HTC Vive, the first two major consumer headsets, were both released recently—are, conversely, characterized by caution, as if their makers were aware that the true shape and potential of V.R.’s arcane power are unknown. “We haven’t yet found an effective way to scare people in V.R. without making it a personal transgression,” Stephan said. “Long-term, perhaps it’s a case of building literacy in players and viewers so they understand when the scares are coming. For now, I think that means taking it slow.”