An international team of scientists worked together using magnetic resonance imaging (MRI) technology to map the three-dimensional, scaffold fiber architecture of the brain. This technology determined that the pathways of the brain pass through tissue that resembles a grid-like structure. Read more in this news release.
Credit: NSF and Harvard University
Experiments conducted at Boston University (BU) and ATR Computational Neuroscience Laboratories in Kyoto, Japan, have demonstrated that through a person's visual cortex, researchers could use decoded functional magnetic resonance imaging (fMRI) to induce brain activity patterns to match a previously known target state and thereby improve performance on visual tasks. Read more in this news release.
Credit: Nicolle Rager Fuller, National Science Foundation
The complexity of the neural network that supports vision has long baffled scientists. Researchers at the University of California at Berkeley and the University of California at San Francisco have been able to follow entire populations of retinal and brain cells in their test animal--the zebrafish larva--and solve some of the mysteries of the neural circuit that underlies its vision. Read more in this news release.
Credit: Zina Deretsky, National Science Foundation
An artificial retina being developed to return eyesight to people who lost their sight due to certain diseases is one of three NSF-funded projects recognized by Popular Mechanics with innovation Breakthrough Awards. The artificial retina technology is an experimental system that helps individuals suffering from either macular degeneration or retinitis pigmentosa. The project, along with 18 others, was featured in the November 2010 issue of Popular Mechanics. Find out more in this video discussion.
Credit: USC BMES ERC
The Division of Behavioral and Cognitive Sciences (BCS) of the Directorate for Social, Behavioral and Economic Sciences supports research to develop and advance scientific knowledge on human cognition, language, social behavior and culture, as well as research on the interactions between human societies and the physical environment.
Neuroscientists at Georgetown University Medical Center have found that an area known to be important for reading in the left visual cortex contains neurons that are specialized to process written words as whole word units.
Computational neuroscientists at Carnegie Mellon University have developed a computational model that provides insight into the function of the brain's visual cortex and the information processing that enables people to perceive contours and surfaces.
April 2, 2012
Seeing Beyond the Visual Cortex
Research could lead to new rehabilitative therapies when visual cortex is damaged
It's a chilling thought--losing the sense of sight because of severe injury or damage to the brain's visual cortex. But, is it possible to train a damaged or injured brain to "see" again after such a catastrophic injury? Yes, according to Tony Ro, a neuroscientist at the City College of New York, who is artificially recreating a condition called blindsight in his lab.
"Blindsight is a condition that some patients experience after having damage to the primary visual cortex in the back of their brains. What happens in these patients is they go cortically blind, yet they can still discriminate visual information, albeit without any awareness." explains Ro.
While no one is ever going to say blindsight is 20/20, Ro says it holds tantalizing clues to the architecture of the brain. "There are a lot of areas in the brain that are involved with processing visual information, but without any visual awareness." he points out. "These other parts of the brain receive input from the eyes, but they're not allowing us to access it consciously."
With support from the National Science Foundation's (NSF) Directorate for Social, Behavioral and Economic Sciences, Ro is developing a clearer picture of how other parts of the brain, besides the visual cortex, respond to visual stimuli.
In order to recreate blindsight, Ro must find a volunteer who is willing to temporarily be blinded by having a powerful magnetic pulse shot right into their visual cortex. The magnetic blast disables the visual cortex and blinds the person for a split second. "That blindness occurs very shortly and very rapidly--on the order of one twentieth of a second or so," says Ro.
On the day of Science Nation's visit to Ro's lab in the Hamilton Heights section of Manhattan, volunteer Lei Ai is seated in a small booth in front of a computer with instructions to keep his eyes on the screen. A round device is placed on the back of Ai's head. Then, the booth is filled with the sound of consistent clicks, about two seconds apart. Each click is a magnetic pulse disrupting the activity in his visual cortex, blinding him. Just as the pulse blinds him, a shape, such as a diamond or a square, flashes onto a computer screen in front of him.
Ro says that 60 to nearly 100 percent of the time, test subjects report back the shape correctly. "They'll be significantly above chance levels at discriminating those shapes, even though they're unaware of them. Sometimes they're nearly perfect at it," he adds.
Ro observes what happens to other areas of Ai's brain during the instant he is blinded and a shape is flashed on the screen. While the blindness wears off immediately with no lasting effects, according to Ro, the findings are telling. "There are likely to be a lot of alternative visual pathways that go into the brain from our eyes that process information at unconscious levels," he says.
Ro believes understanding and mapping those alternative pathways might be the key to new rehabilitative therapies. "We have a lot of soldiers returning home who have a lot of brain damage to visual areas of the brain. We might be able to rehabilitate these patients," he says. And that's something worth looking into.
Any opinions, findings, conclusions or recommendations presented in this material are only those of the presenter grantee/researcher, author, or agency employee; and do not necessarily reflect the views of the National Science Foundation.