Scientists Show How Tiny Cells Deliver Big Sound In Cochlea (via ScienceDaily)
not the most interesting article, but I like the cochlea drawing
‘Bionic Eye’ May Help Blind See: Retinal Prosthesis Shown To Restore Partial Vision (via ScienceDaily)
A new artificial retina, an array of electrodes implanted on the back of the eye, has been found to restore partial vision to totally blind people.
Stimulating Sight: Retinal Implant Could Help Restore Vision To The Blind People
Inspired by the success of cochlear implants that can restore hearing to some deaf people, researchers at MIT are working on a retinal implant that could one day help blind people regain a useful level of vision.
The eye implant is designed for people who have lost their vision from retinitis pigmentosa or age-related macular degeneration, two of the leading causes of blindness. The retinal prosthesis would take over the function of lost retinal cells by electrically stimulating the nerve cells that normally carry visual input from the retina to the brain.
Such a chip would not restore normal vision but it could help blind people more easily navigate a room or walk down a sidewalk…. (continues @ ScienceDaily)
Genetic Engineering to Cure Color Blindness
Scientists say they are a step closer to curing colour blindness using gene therapy. A US team were able to restore full colour vision to adult monkeys born without the ability to distinguish between the colours red and green….
Until now scientists had not thought it was possible to manipulate the adult brain in this way. It was considered that adding new sensory information, such as the visual receptors necessary for perfect colour vision, could only be done in the earliest years of life when the brain is at its most malleable or “plastic”.
But Professor Jay Neitz and his team were able to introduce therapeutic genes into the light-sensing cells at the back of the eye of adult male squirrel monkeys.
The therapeutic genes contained the necessary DNA code to enable the light-sensing cells to distinguish between red and green - something lacking in the male monkeys. Tests revealed the gene therapy was a success. The male monkeys now possessed the necessary photopigments to see all colours and were able to correctly pick out red from green on computer image tests. The monkeys were treated over two years ago and their improvement in colour vision has remained stable since…. (more @ BBC News)
Perceptual Rivalry: Nostrils Alternate To Process Competing Odors
When the nose encounters two different scents simultaneously, the brain processes them separately through each nostril in an alternating fashion.
For the study, 12 volunteers sampled smells from two bottles containing distinctively different odors. One bottle had phenyl ethyl alcohol, which smells like a rose, and the other had n-butanol, which smells like a marker pen. The bottles were fitted with nosepieces so that volunteers could sample both scents simultaneously — one through each nostril.
During 20 rounds of sampling, all 12 participants experienced switches between smelling predominantly the rose scent and smelling predominantly the marker scent. Some experienced more frequent and drastic switches than others, but there was no predictable pattern of the switch across the whole group of volunteers or within individuals.
Chen said this “binaral rivalry” between the nostrils resembles the rivalry that occurs between other pairs of sensory organs. When the eyes simultaneously view two different images — one for each eye — the two images are perceived in alternation, one at a time. And when alternating tones an octave apart are played out of phase to each ear, most people experience a single tone that goes back and forth from ear to ear…. (more @ ScienceDaily)
“Gecko Vision:” Key to Future Multifocal Contacts? (via ScienceDaily)
Nocturnal geckos are among the very few living creatures able to see colors at night, and scientists’ discovery of series of distinct concentric zones may lead to insight into better cameras and contact lenses.
The key to the exceptional night vision of the nocturnal helmet gecko is a series of distinct concentric zones of different refractive powers, according to a new study.
This multifocal optical system is comprised of large cones, which the researchers calculated to be more than 350 times more sensitive than human cone vision at the human color vision threshold….
The nocturnal geckos’ multifocal optical system gives them an advantage because light of different ranges of wavelengths can focus simultaneously on the retina. Another possible advantage of their optical structure is that their eyes allow them to focus on objects at different distances. Therefore the multifocal eye would generate a sharp image for at least two different depths. Geckos that are active during the day do not possess the distinct concentric zones and are considered monofocal….
Dolphins Maintain Round-The-Clock Visual Vigilance (via ScienceDaily)
Dolphins have a clever trick for overcoming sleep deprivation. Sam Ridgway from the US Navy Marine Mammal Program explains that they are able to send half of their brains to sleep while the other half remains conscious. What is more, the mammals seem to be able to remain continually vigilant for sounds for days on end.
Wimps Hear Dangerous Noises Differently
Scrawnier people are more likely to perceive an approaching sound as closer than it actually is. This connection between physical fitness and the brain’s auditory system may have evolved to help the weak get out of the way of approaching danger…. (continues @ ScienceDaily)
Tumblr Powered Bill Israel Designed
