The Body Electric

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The projected images — an X or an H, for example, or basic forms such as blocks and circles, tables and chairs — contain live pixels that the video camera registers as a flash when it passes over them. As the camera crosses a live pixel, it sends a signal to the transmitter, which passes it on to the stimulator, which sends an electrical charge to Marie's optic nerve. The result: Marie sees a series of flashes that join up to form recognizable shapes.

Since the camera's visual range is narrow, Marie has to scan an image by slowly moving her head from left to right and up and down until she's covered the entire screen. As the camera criss-crosses the visual field, a rapid series of electrical stimulations is sent to her optic nerve. The number of electrical stimulations depends on the number of live pixels on the screen; the more there are, the easier and quicker it is to compile an image. Marie reconstructs the image from what appear to be a series of strobe flashes, an experience that's a bit like watching a miniature stadium billboard, on which images are also compiled from groups of individual flashing lights.

In the experiments carried out to date, Veraart has noted a correspondence between where Marie sees a flash and that image's actual location in space, which means that the flashes transmitted to Marie's optic nerve correlate with the outside world. Veraart has also discovered that different electrical pulses lead to different perceptions. One type of pulse might always produce a yellow image, for example, while another might always produce red. If this turns out to be the case, Veraart and his team intend to compile a lexicon of correspondences so that specific visual stimuli can be easily reproduced. Imagine public spaces seeded with a kind of invisible braille, live pixels embedded in doors, stairways and streetcorners that blind MIVIP users could employ to see important information about their immediate surroundings. Veraart and his colleagues are working to refine the technology so that the blind could actually see obstacles like chairs and tables in this way.

The MIVIP is still a cumbersome and limited device. It hasn't given Marie her normal vision back. At best, it can help restore mobility by helping people avoid obstacles, recognize landmarks in unfamiliar environments and detect very simple shapes. "This is not true vision," Veraart stresses. "And it's definitely not a cure for blindness. It's something to help people better cope with their impairment. It's like a wheelchair: it doesn't help people walk again, but it does help them get around. As a technological solution, that's not bad at all." Marie agrees. She has undergone extensive, and dangerous, brain surgery to use the MIVIP and she still shows up every week at Veraart's lab for more tests and experiments. "Even if I recover only light and shadows," she says, "it would still be worth it."

Computer pioneer Norbert Wiener once advised, "Render unto man the things which are man's and unto the computer the things which are the computer's." As the experiences of people like Stelarc, Brian Holgersen and Marie show, it's becoming increasingly difficult to tell the difference.

James Geary 2002. This is an edited excerpt from Geary's book The Body Electric: An Anatomy of the New Bionic Senses, published in the U.K. by Weidenfeld & Nicolson