Moving closer to a 'Matrix'-style virtual world

Virtual Oprah
Another prerequisite for a convincing virtual world is the ability to carry on a conversation with a computer-generated counterpart that easily reacts to non-verbal cues, such as tone of voice and facial expression, says Roddy Cowie, a professor of psychology at Queen’s University Belfast in Northern Ireland. Most research has focused on basic comprehension, but Cowie argues that non-linguistic cues are critical for supporting comprehensible human-computer dialogue, “like a trellis that can support roses and ivy and all the rest.”

Computers have a rather shallow ability to infer, and understanding the signals indicating interest, concern and other emotions further complicate the problem. “You need to know whether someone is interested in the conversation, or has completely switched off,” Cowie says.

Enter Virtual Oprah.

“We noticed that chat show hosts like Oprah seemed to be very good at conversation that bypassed most of the linguistic complexities. They had a repertoire of phrases that kept people talking, and even raised the intensity of their conversation, without much reference to linguistic details,” Cowie says. The same holds true for people trying to communicate with a foreign speaker: “You can keep conversation going for a long time if you can make a few noises they understand, in the right tone of voice.”

A system known as Sensitive Artificial Listener, or SAL, uses that observation as a trellis. Equipped with stock phrases and ‘soft skills’ such as nods, smiles, tones of voice and sensitivity to nonverbal cues, the system modeled on Oprah’s linguistic behavior offers a framework aimed at keeping a conversation going for more than a half-hour.

Teaching a computer what to say and how to say it could prove a boon for teaching applications that recognize when a pupil is having difficulty. Ditto for computer-based systems marketed as companions or lifestyle coaches. “If a machine is going to share large, sensitive parts of a person’s life, it had better have some sensitivity,” says Cowie, part of a European consortium hoping to do just that through its SEMAINE project (Sustained Emotionally coloured Machine-human Interaction using Nonverbal Expression).

Eventually, the project’s SAL brainchild could lead to an empathetic avatar nodding sympathetically and saying all the right things while you hash out your latest sob story. But what if you really need a virtual hug?

Simulated touch
Ralph Hollis, a research professor in the Robotics Institute at Carnegie Mellon University in Pittsburgh, isn’t about to promise that breakthrough just yet. His laboratory team, however, has harnessed a technology called magnetic levitation to create one of the most sensitive haptic, or touch-based, interfaces in the world.

The magnetic levitation device, resembling a shallow bowl welded into a half-sphere, uses magnetic fields to hover above its base. A handle within the bowl, or flotor, can be freely moved to control the position and orientation of a virtual object on a computer display. As that virtual object encounters obstacles, signals flow to six electrical coils embedded within the flotor, resulting in ultra-fine haptic feedback.  

How sensitive? For one demonstration, researchers affixed an ant to a microscope slide and used a sewing needle connected to a magnetic levitation device to tug on one of the ant’s legs. That subtle tension was readily felt by someone using another haptic device in a separate room.

The high resolution, Hollis says, comes from avoiding the mechanics of robotic arms used to simulate touch. Most arms move up and down, forward and backward and left and right — enough to control a point in a three-dimensional space. But controlling both the position and orientation of an object requires all six degrees of freedom, including roll, pitch and yaw, quickly adding expense and complexity to mechanical structures.  “The fidelity of the interaction suffers from having all these motors and links and cables and gears and especially in the case of having six degrees of freedom,” he says. “So that’s a quandary.”

The new device sidesteps the problem with magnetic fields and only one moving part, letting users experience the same touch sensation they’d get from running a finger along a rough tabletop. The new system also boasts better simulations of hard contact, such as a three-dimensional virtual object hitting an appropriately hard virtual wall. “For most systems, that impact feels mushy, it feels like you’re hitting a block of foam,” Hollis says.

The downside to all this refinement is a limited range of motion, analogous to being able to move your computer’s mouse only a small distance across the screen. Hollis and his colleagues have been able to magnify that motion in the virtual world by a factor of 30, but simulating entire arm movements would be impractical (sorry, no hugs). Instead, Hollis says the range of motion could be enormously useful for finger-focused activities like microsurgery — or dentistry.

“We think our device is well-matched to the motion of range of doing virtual dentistry,” he says. “We have the ability to simulate contact with very hard surfaces, like tooth enamel, as well as with softer gum tissue.” A spin-off company, called Butterfly Haptics, will begin producing the haptic devices this summer, although Hollis says specific applications, whether for dentistry or brain surgery training, will be up to individual buyers to develop.

Nevertheless, the new agility means that in just a few years, an avatar could convincingly tell a depressed dentist in training, “I feel your pain,” and then wince as the dental scaler hits her virtual gums yet again.

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