Word: optical
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...still manage to recognize objects and read with difficulty. But then as her cone cells failed, this last narrow window on the world snapped shut and she was left completely blind - even though her retina retained a healthy connection to the visual centers of her brain through a functioning optic nerve. Marie's implant splices into the live line of the optic nerve to enable her to see again...
Marie's artificial visual system is called the Microsystem-based Visual Prosthesis (MIVIP) and was designed by Claude Veraart and collaborators at the University of Louvain. The MIVIP consists of a cuff electrode implanted around Marie's right optic nerve. The electrode wraps around the optic nerve like the little plastic sheath on the end of a shoelace. It is connected to a thin cable that snakes its way from the optic nerve exiting the back of Marie's eye and weaves around the outside of her brain to the stimulator implanted in a small cavity in her cranium...
...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...
...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...
...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...