…reality, as we experience it, might be a mental stage set—a representation of the world, rather than the world itself. Having an O.B.E. (out of body experience) could be like visiting the set at night, when it wasn’t being used…Some internal mental system must function as an invisible, unconscious set dresser, making an itch feel like an itch, coloring the sky blue and the grass green.
It isn’t just that we live inside a model of the external world, Metzinger wrote. We also live inside models of our own bodies, minds, and selves. These “self-models” don’t always reflect reality, and they can be adjusted in illogical ways. They can, for example, portray a self that exists outside of the body—an O.B.E.
Metzinger and Blanke set about hacking the self-model. Along with the cognitive scientists Bigna Lenggenhager and Tej Tadi, they created a virtual-reality system designed to induce O.B.E.-like episodes. In 2005, Metzinger put on a virtual-reality head-mounted display—a headset containing a pair of screens, one for each eye, which together produce the illusion of a 3-D world. Inside, he saw his own body, facing away from him, standing in a room. (It was being filmed by a camera placed six feet behind him.) He watched as Lenggenhager stroked its back. Metzinger could feel the stroking, but the body to which it was happening seemed to be situated in front of him. He felt a strange sensation, as though he were drifting in space, or being stretched between the two bodies. He wanted to jump entirely into the body before him, but couldn’t. He seemed marooned outside of himself. It wasn’t quite an out-of-body experience, but it was proof that, using computer technology, the self-model could easily be manipulated. A new area of research had been created: virtual embodiment.
With a team of various collaborators, Slater and Sanchez-Vives have created many other-body simulations; they show how inhabiting a new virtual body can produce meaningful psychological shifts. In one study, participants are re-embodied as a little girl. Surrounded by a stuffed bear, a rocking horse, and other toys, they watch as their mother sternly demands a cleaner room. Afterward, on psychological tests, they associate themselves with more childlike characteristics. (When I tried it, under the supervision of the V.R. researcher Domna Banakou, I was astonished by my small size, and by the intimidating, Olympian height from which the mother addressed me.) In another, white participants spend around ten minutes in the body of a virtual black person, learning Tai Chi. Afterward, their scores on a test designed to reveal unconscious racial bias shift significantly. “These effects happen fast, and seem to last,” Slater said. A week later, the white participants still had less racist attitudes. (The racial-bias results have been replicated several times in Barcelona, and also by a second team, in London.) Embodied simulations seem to slip beneath the cognitive threshold, affecting the associative, unconscious parts of the mind. “It’s directly experiential,” Slater said. “It’s not ‘I know.’ It’s ‘I am.’ ”
“I think that, in the human self-model, there are many layers. Some layers are transparent, like your bodily perceptions, which seem absolutely real. You just look”—he gestured toward a chair next to us—“and the chair is there. Others are opaque, like our cognitive layer. When we’re thinking, we know that our thoughts are internal mental constructs, which could be true or false.” As a philosopher, Metzinger’s method has been to see if the transparent can be made opaque. In books such as “Being No One” and “The Ego Tunnel,” he aims to show that aspects of our experience which we take to be real are actually “complex forms of virtual reality” created by our brains.
Imagine that you are sitting in the cockpit of an airplane, surrounded by instruments and controls. It’s a futuristic cockpit, with no windows; where the windshield would be, a computer displays the landscape. Using this cockpit, you can pilot your plane with ease. Still, there are questions you are unable to answer. Exactly what kind of plane are you flying? (It could be a Boeing 777 or an Airbus A380.) How accurate is the landscape on the screen? (Perhaps night-vision software has turned night to day.) When you throttle up the engines, you feel a rumbling and hear a roar. Does this mean the plane is accelerating—or could those effects have been simulated? Both scenarios might be true. You could be using a flight simulator to fly a real plane. This, in Metzinger’s view, is how we live our lives.
The instruments in an airplane cockpit report on pitch, yaw, speed, fuel, altitude, engine status, and so on. Our human instruments report on more complicated variables. They tell us about physical facts: the status of our bodies and limbs. But they also report on mental states: on what we are sensing, feeling, and thinking; on our intentions, knowledge, and memories; on where and who we are. You might wonder who is sitting in the cockpit, controlling everything. Metzinger thinks that no one is sitting there. “We” are the instruments, and our sense of selfhood is the sum of their readouts. On the instrument panel, there is a light with a label that says “Pilot Present.” When the light is on, we are self-conscious; we experience being in the cockpit and monitoring the instruments. It’s easy to assume that, while you’re awake, this light is always on. In fact, it’s frequently off—during daydreams, during much of our mental life, which is largely automatic and unconscious—and the plane still flies.
Two facts about the cockpit are of special importance. The first is that although the cockpit controls the airplane, it is not itself an airplane. It’s only a simulation—a model—of a larger, more complex, and very different machine. The implication of this fact is that the stories we tell about what happens in the cockpit—“I pulled up on the stick”; “I touched my jacket”—are very different from the reality of what is happening to the system as a whole. The second fact, harder to grasp, is that we cannot see the cockpit. Even as we consult its models of the outer and inner worlds, we don’t experience ourselves as doing so; we experience ourselves as simply existing. “You cannot recognize your self-model as a model,” Metzinger writes, in “Being No One.” “It is transparent: you look right through it. You don’t see it. But you see with it.” Our mental models of reality are like V.R. headsets that we don’t know we are wearing. Through them, we experience our own inner lives and have inner sensations that feel as solid as stone. But in truth:
Nobody ever was or had a self. All that ever existed were conscious self-models that could not be recognized as models. . . . You are such a system right now. . . . As you read these sentences, you constantly confuse yourself with the content of the self-model activated by your brain.
Do you know what an ‘illusion of control’ is?” he asked, mischievously. “If people are asked to throw dice, and their task is to throw a high number, they throw the dice harder!” He believes that many experiences of being in control are similarly illusory, including experiences in which we seem to control our own minds. Brain imaging, for example, shows that our thoughts begin before we’re aware of having them. But, Metzinger said, “if a thought crosses the boundary from unconsciousness to consciousness, we feel, ‘I caused this thought.’ ” The sensation of causing our own thoughts is also just another feature of the self-model—a phantom sensation conjured when a readout, labelled “thinking,” switches from “off” to “on.” If you suffer from schizophrenia, this readout may be deactivated inappropriately, and you may feel that someone else is causing your thoughts. “The mind has to explain to itself how it works,” he said, spreading his hands.
Lately, Metzinger has been thinking about his own experience as a meditator. At the center of the meditative experience is the exercise and cultivation of mental autonomy: when the meditator’s mind wanders, he notices and arrests that process, gently returning his mental focus to his breath. “The mind says, ‘I am now re-directing the flashlight of my attention to this,’ ” Metzinger said. “But the thought ‘I am redirecting my mind-wandering’ might itself be another inner story.” He leaned back in his chair and laughed. “It might be that the spiritual endeavor for liberation or detachment can lead to new illusions.”
…you are not the model. You are the whole system—the physical, biological organism in which the self-model is rendered, including its body, its social relationships, and its brain. The model is just a part of that system.” The “I” we experience is smaller than, and different from, the totality of who and what we are.
It turns out that we do, in this sense, possess subtle bodies; we also inhabit subtle selves. While a person exists, he feels that he knows the world and himself directly. In fact, he experiences a model of the world and inhabits a model of himself. These models are maintained by the mind in such a way that their constructed nature is invisible. But it can sometimes be made visible, and then—to a degree—the models can be changed. Something about this discovery is deflating: it turns out that we are less substantial than we thought. Yet it can also be invigorating to understand the constructed, provisional nature of experience. Our perceptions of the world and the self feel real—how could they feel otherwise?—but we can come to understand our own role in the creation of their apparent realness.