The chip in Murcheson’s eye

Paul Raven @ 03-11-2010

The Guardian reports on a successful cyborg vision implant procedure; bonus points for the industry-standard soundbite disclaimer:

“The visual results they were able to achieve were, up until now, thought to be in the realms of science fiction,” said MacLaren.

The guy must read some pretty strict Mundane SF if he thinks this represents the apogee of artificial vision acuity as portrayed in science fiction…

A man left blind by a devastating eye disease has been able to read letters, tell the time and identify a cup and saucer on a table after surgeons fitted him with an electronic chip to restore his vision.

Whoa.

Snark aside, it’s actually a pretty impressive step along the path to full-on artificial vision.

Miikka Terho, 46, began losing his eyesight as a teenager and was completely blind when he joined a pilot study to test the experimental eye chip at the University of Tübingen in Germany.

[…]

“I’ve been completely blind in the central area for about 10 years. I had no reading ability and no way of recognising anybody any more. When the chip was first turned on, I just saw flashes and flickering. It didn’t make any sense. But in a matter of hours, everything started to get clearer and clearer,” Terho said.

“When I looked at people for the first time, they looked like ghosts. I knew it was a person, but they were hazy. Then things got sharper.

“It was such a good feeling to be able to focus on something, to see something right there, and maybe even reach out and grab it. I wasn’t able to identify what was in front of me on the street, but I knew when something was there, so I didn’t walk into it,” he added.

Interesting to note it took a while for the guy to start making sense of the input; neuroplasticity in action, maybe? Or just long-dormant visual centres slowly reopening for business? Whichever it is, it’s nice to find a story where technology is demonstrably improving people’s lives.


Blindsight’s origins uncovered

Paul Raven @ 25-06-2010

No, not the (excellent) Peter Watts novel… but the neurological phenomenon for which it is named. Ars Technica boils down a new paper published in Nature:

The authors worked with two macaques that have small lesions in their primary visual cortexes, which leave them unable to respond to visual cues in a subset of their visual field. A fair amount of work went in to defining precisely the areas within the visual field that were no longer effective, and confirming that stimuli in those areas could still induce activity (measured via functional MRI) in the remaining visual cortexes.

The authors then focused on a structure called the lateral geniculate nucleus (LGN), which acts as a relay point for signals travelling between the retina and the primary visual cortex. Other work had shown that the LGN also has projections to a number of secondary visual areas, suggesting that it may serve as a major hub in the visual system.

To test this suggestion, the authors injected the LGN with a chemical that activates the receptor for a major inhibitory signaling molecule (the chemical, THIP, is what’s termed a “GABAA-receptor agonist”). When the chemical is present, nerve cells receive a signal telling them to stop signaling, so this this injection has the effect of shutting the LGN down entirely.

The treatment was highly effective. With the LGN shut down, visual stimuli that normally induce a blindsight response didn’t elicit any response from the visual centers of the macaques.

And here’s a blindness-related bonus story with some feel-good we-can-fix-anything-eventually overtones (as well as some science-not-the-work-of-Beelzebub-after-all undertones) to set you up for the weekend: restoring sight to blinded human patients with stem cell therapy. Yay, science!


Sci-fi no more: bionic eyeball implants

Paul Raven @ 31-03-2010

Another genre cliché becomes reality, as the imaginatively-named company Bionic Vision Australia prepares to install the first in-human deployment of a prototype eyeball implant designed to “deliver improved quality of life for patients suffering from degenerative vision loss caused by retinitis pigmentosa and age-related macular degeneration” [via KurzweilAI.net]. Er, what?

The device, which is currently undergoing testing, consists of a miniature camera mounted on glasses that captures visual input, transforming it into electrical signals that directly stimulate surviving neurons in the retina. The implant will enable recipients to perceive points of light in the visual field that the brain can then reconstruct into an image.

Ah, right. Why didn’t you just say so, eh? Here’s a video:


Fly Simulator

Paul Raven @ 04-08-2009

house flyProof, if such were needed, that science is awesome and strange in equal measure: have you ever wondered how the hell flies can so effectively dodge your every effort to swat them? Sure you have – but you don’t have a lab full of stuff that you could use to find out the answer. The biologists at the Max Planck Institute for Neurobiology do, however, so they’ve built a flight simulator and wired it into the brain of an immobilised blowfly.

As the fly responded to virtual objects flying around it, the scientists used a fluorescent microscope to watch how its brain processed the images. Compared to people, who can distinguish a maximum of 25 discrete images per second, blowflies are visual virtuosos: They can sense up to 100 separate images per second and respond fast enough to change their flight direction.

No mention of any progress on discovering why flies, despite their incredible visual acuity, spend hours battering themselves against a closed window when there’s an open one right next to it… [image by dafydd359]


Blinded by the laser light

Tom James @ 30-03-2009

green_laserIn what won’t be the last instances of laser-related “friendly fire” three US soldiers in Iraq have been hospitalised, and one has been blinded in one eye, by a green dazzling laser:

Since November 2008, a single unit in Iraq “has experienced 12 green-laser incidents involving 14 soldiers and varying degrees of injury. Three soldiers required medical evacuation out of Iraq and one soldier is now blind in one eye,” writes Sgt. Crystal Reidy

[from Wired][image from Wired]


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