Human echolocation activates visual parts of the brain
WE all know that bats and dolphins use echolocation to navigate, by producing high frequency bursts of clicks and interpreting the sound waves that bounce off objects in their surroundings. Less well known is that humans can also learn to echolocate. With enough training, people can use this ability to do extraordinary things. Teenager Ben Underwood, who died of cancer in 2009, was one of a small number of blind people to master it. As the clip below shows, he could use echolocation not only to navigate and avoid obstacles, but also to identify objects, rollerskate and even play video games.
Very little research has been done on human echolocation, and nothing is known about the underlying brain mechanisms. In the first study of its kind, Canadian researchers used functional magnetic resonance imaging (fMRI) to monitor the brain activity of two blind echolocation experts. Their findings, published today in the open access journal PLoS ONE Psychologist Lore Thaler of the University of Western Ontario and her colleagues recruited two expert echolocators for the new study. One, a 43-year-old man referred to as EB, was born with retinoblastoma - a form of cancer that affects cells in the retina - and had both eyes removed at 13 months of age. The other, a 27-year-old man known as LB, lost his vision at the age of 14, following degeneration of the optic nerve, which carries visual information from the eye to the brain. Both have trained themselves to be expert echolocators. Both of them use click-based echolocation on a daily basis, to navigate their home cities and explore unfamiliar ones, go hiking or play basketball. The researchers seated their participants in a sealed room, placed various objects in front of them, and asked them to produce echolocation clicks. As they did so, the sounds they produced - and the faint echoes - were recorded with high quality stereo equipment. They also asked the participants to do the same thing in an outdoor courtyard surrounded by buildings, and made more recordings. Some of these contained echoes produced by a tree, car or lamp-post, while others did not. EB and LB could accurately determine the size, shape, position and movements of objects in both situations. Crucially, they could do the same from the sound recordings when they were played back later. EB, for example, could distinguish a 3° difference in the position of a pole in the sealed room, as well as from the pre-recorded sounds. LB, was slightly less accurate, distinguishing 9° differences in position of the pole while in the room, and 22° differences from the recordings.
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Fundus autofluorescence showed granular areas of hypoautofluorescence in the macula as well as in the posterior pole surrounding the optic nerve where speckled hyperautofluorescence was intermixed with hypoautofluorescent areas (Figure 3). Figure 1.
these bio-mirrors to be placed in the human retina as well, then the combination of retinal mirrors (similar to felines) and photsensitive bio luminescent cells converting invisible forms of light into visible forms that the optic nerve can read,
The other, a 27-year-old man known as LB, lost his vision at the age of 14, following degeneration of the optic nerve, which carries visual information from the eye to the brain. Both have trained themselves to be expert echolocators.
They relay what they sense to the optic nerve which carries the information back into the brain. The problem is, the optic nerve ends in the field of the retina itself. This is a little like having to plug the power cable for a TV directly into the
Nelson testified Kacy suffered two partially collapsed lungs, lacerations to her liver, bleeding in her abdominal and chest cavity, retinal hemorrhaging and optic nerve damage in addition to her “massively swollen brain.” The injuries were caused by
Optic Nerve | Faithful Gear
I got my eyes examed an she discovered that one of my optic nerve is larger than the other and told not to worry but to keep an eye it. but im curious to know if im risk for glaucoma.
Courtney, you have posted your question in the wrong section. Go back to the health section and post your question under optical. Saying that, I think you should get a second opinion with an ophalmologist. Who is supposed to be keeping and eye on it?
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It is a formula in which every ingredient counts, and it is designed to provide no less than 14 different nutrients in the optimal am… This insightful educational film explores the inner workings of the human eye, its care, and its diseases – plus somewhat graphic footage of eye injuries. The first part shows how eyes are used and how vision is discovered at the early stage of development of an infant. We learn through animated diagrams how the mechanism of the eye works.
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Human malformations and related anomalies
9.13 Optic Nerve Hypoplasia Definition Optic nerve hypoplasia is a ... Patients with septo-optic dysplasia also have problems learning tasks that require ...Ocular pathology
Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in human optic nerve head astrocytes. Glia 33:205, 2001 Agapova OA, ...The human hypothalamus, Handbook of clinical neurology. Neuropathology of the human hypothalamus and adjacent brain structure / Dick F. Swab
Congenital mid line defects: optic nerve hypoplasia and septo-optic dysplasia ( De ... (a) Optic nerve hypoplasia Optic nerve hypoplasia is a congenital ...Image modeling of the human eye
7.2.1 Optic Disc Configuration In a normal eye, there is large variability in ... The size of the optic disc varies from approximately 0.80 to 6 mm2 [27]. ...Optic Nerve Disorders, Diagnosis and Management
Microvasculature of the human optic nerve. Am J Ophthalmol 1995;120(1):92–102. 36. Hayreh SS, Piegors DJ, Heistad DD. Serotonin- induced constriction of ...Day-to-day Posts Directory
optic nerve (anatomy) -- Britannica Online Encyclopedia
The vast majority of optic nerve fibres convey information ... Facts about optic nerve: embryological development, as discussed in human embryology (biology): Cranial nerves: ...
Optic nerve | Define Optic nerve at Dictionary.com
Optic nerve definition, either one of the second pair of cranial nerves, consisting of sensory fibers that conduct impulses from the retina to the brain. See more.
Eye - Stem cells to replace the optic nerve
Eye is the official journal of the Royal College of Ophthalmologists. ... futuristic goal—the regeneration of the human optic nerve in an eye blind from glaucoma. ...
Human eye - Wikipedia, the free encyclopedia
The human eye can distinguish about 10 million colors.[1] In common with the eyes of ... optic disk (papilla), where vessels entering the eye pass across and optic nerve ...
Research Paths, International Foundation for Optic Nerve Disease
Why are retinal ganglion cells (RGCs) prone to death in optic nerve disease? ... biology to learn exactly where and how optic nerve disease occurs. ...