Tagged: eyes
The Birds
In my vision modeling class this week, we were learning about the structure of the (primate) visual cortex and one of my classmates posed an interesting question: how is it that birds sustain such amazing visual acuity when they don’t seem to have the cortical volume to process that detailed information? In other words, how does a bird brain deal witha bird’s eye view? I’m curious – and I still am, because so far I have not found a lot of research on the topic. Indeed, I imagine it’s difficult to come up with a definitive way to determine what a bird is experiencing for the sake of a laboratory experiment. Although, if I had to hazard a guess, perhaps much of a bird’s reaction to what it sees relies on more primitive structures – maybe birds rely more on instinct than interpretation? While this seems to remain mysterious, scientists do know some neat stuff about how birds’ eyes function in ways that allow them to see what we can’t. Check it out!
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"I for one welcome our new computer overlords"
The parting words of Ken Jennings in last year's Jeopardy match against Watson, a computer seemingly able to decipher and process language, are a milestone for robotic innovations. Advancements in neuroscience and robotics have focused on giving robots human-like intelligence and processing skills. This concept has been depicted numerous times in popular culture, many times in terms of robotic rebellion, for example in movies such as I, Robot or WALL-E.
Recent robotics research leaves us with a couple of questions. Are really focusing on the right aspects of advancing in robotic technologies? Instead of perfecting intelligence and processing, why not instead focus on perfecting human emotion? More
Behind Closed Eyes: An Ayahuasca Experience
Ayahuasca is found to produce life-changing visions but can it also produce life-changing cures?
"As I closed my eyes, images - if they can be called such - began racing at an ever-increasing speed before me. Swirls of colors, shapes, forms, textures and sounds simply overpowered me to the point where I became immobile. Like many others before me, no doubt, I became somewhat frightened. What had I let myself in for? When I opened my eyes, the phantasmagoria of forms vanished, and I saw myself in the same room with the others"
Donald M. Topping's description is very similar to the accounts many others have given. He brought up many questions on the vividness of visions produced after his very first ingestion of the hallucinogenic brew Ayahausca. What underlying brain mechanisms allow potentially healing, uplifting and fearful experiences to occur behind closed eyelids? That is what Draulio B. de Araujo and others sought out to find. More
Progress for the Artificial Retina
For patients who have lost their sight to various eye diseases, artificial retina technology allows them to experience limited vision once more.
The external parts of the artificial retina device include glasses with a mounted camera and a small computer.
The device also includes an electrode implanted onto the patient's retina. When the camera "sees" an image, the computer is able to translate these into a pattern of neural signals. This pattern is then transmitted to the implanted electrode, and directly stimulates the optic nerve. These signals are then able to be processed by the brain and interpreted as very rudimentary images.
The first artificial retina to be implanted in a patient, known as Argus I, included only sixteen electrodes that stimulated the optic nerve. However, the patient with this implant was still able to tell the differences between light and dark, and could make out basic shapes. The newer version of the technology, Argus II, now includes sixty electrodes. However, it is still limited in that patients can only tell the differences between light and dark areas, and can only see shapes, outlines, and blurs, and not detailed images. Regardless, this is a large improvement over no sight, and patients with the implant are satisfied with simply a partial regain of their vision, and are hopeful that the technology will continue to improve. As of late, a third model of the artificial retina is in development, and will include over 200 electrodes.
Though the project began almost ten years ago, the implant has recently been approved for patients in Europe. The company has not yet submitted approval to the FDA, but hopes to do so by the end of this year.
Second Sight - How is Argus II Designed to Produce Sight?
CBS News HealthPop - First Artificial Retina Approved in Europe
US Department of Energy Office of Science - About the Artificial Retina Project
Opening Eyes to Learning Difficulties
Learning difficulty and disability has long been a problem for many children, parents and school teachers alike. Dysfunctions such as dyslexia and motor disability have hindered the progress of countless adolescents across the country and continue to do so with every passing day. Now, studies have been performed that may centralize learning difficulties to the eye, rather than the brain itself.
Researchers at the Norwegian University of Science and Technology are conducting research that creates a causal link between motor and learning disabilities and dysfunction in visual perception. For example, people who cannot quickly learn a simple motor task such as catching a ball may have difficulty because the cells in their eyes are not perceiving the stimulus properly. The same rings true in individuals with dyslexia - their eyes may not be correctly processing the visual stimuli of words on the page.
Learning disability has long puzzled victims, observers and scientists.
The ocular cells in contest here are deemed "magno cells" and detect rapid movements in our visual field, creating the movie-like perception we experience on a daily basis. Without these, life would look like a disconnected string of frames - much like a comic book. In a test conducted by the researchers, it was found that individuals with difficulty in mathematics also showed difficulty in tracking the randomized movement of a dot on a screen with their eyes, elucidating a link between eye function efficiency, detection of rapid changes in the environment and learning ability.
In a greater context, this finding may have implications in special education and may change the mindset of those working with individuals with additional learning needs. With this new information, learning disability can be combated from the angle of visual field perception. Techniques aiming to strengthen visual perception and eye efficiency (such as eye movement and tracking exercises) could act as a therapy for learning or motor disability previously thought to be localized in the brain itself.
Source: Science Daily via The Norwegian University of Science and Technology
