Vision

In my article on brain waves and consciousness I looked at some research associating gamma wave activity with consciousness. This is, however, a controversial area in that other researchers have found that such gamma activity is also correlated with eye movements known as saccades: these are the small eye movements that the brain edits out so that we do not perceive the world as a blur as we switch focus. So, are brain gamma waves merely a byproduct of saccadic movements or are they correlated with consciousness or, potentially, both? You can follow the relevant articles and the subsequent…

Our everyday visual perceptions rely upon unfathomably complex computations carried out by tens of billions of neurons across over half our cortex. In spite of this, it does not “feel” like work to see. Our cognitive powers are, in stark contrast, “slow and painful,” and we have great trouble with embarrassingly simple logic tasks. Might it be possible to harness our visual computational powers for other tasks, perhaps for tasks cognition finds difficult? I have recently begun such a research program with the goal of devising ways of converting digital logic circuits into visual stimuli – “…

Specially medicated contact lenses loaded with vitamin E can keep glaucoma medicine near the eye — where it can treat the disease — almost 100 times longer than possible with current commercial lenses, scientists reported today at the ACS National Meeting. Glaucoma is second only to cataracts as the leading cause of vision loss and blindness in the world. It affects almost 67 million people. Eye drops that relieve the abnormal build-up of pressure inside the eye that occurs in glaucoma, are a mainstay treatment. "The problem is within about two to five minutes of putting drops in the eye,…

Researchers writihg in Proceedings of the Royal Society B say they have made a discovery in understanding the origins of human vision.  They say they have determined which genetic 'gateway,' or ion channel, in the hydra is involved in light sensitivity.  Hydra are simple animals that, along with jellyfish, belong to the phylum cnidaria. Cnidarians first emerged 600 million years ago. Complex traits with components of individual evolutionary histories are always more difficult to understand but a gene called opsin is present in vision among vertebrate animals and is responsible…

I really like this optical illusion made by Japanese artist Hajime Ouchi. It's just so simple - just black and white rectangles - and yet has the illusion of both movement and depth. Reminds me a little of some Vasarely images but his were mainly warped spaces - more optical-candy rather than optical-high! "The illusion is caused by random eye movements, which are independent in the horizontal and vertical directions. However, the two types of patterns in the figure nearly eliminate the effect of the eye movements parallel to each type of pattern. Consequently, the neurons stimulated by the…

Migraine sufferers have long complained about how their headaches worsen with bright light, and in case you ever doubted their complaints, Rami Burstein and other researchers from Harvard Medical School and the Moran Eye Center at the University of Utah recently made a giant step in understanding the light-to-headache mechanism in Nature Neuroscience. They found neurons in the rat thalamus sensitive to both light and to the dura (the membrane surrounding the brain). More intriguing than the “how” of light and headaches is the “why”. Why should light be linked with pain mechanisms at all? Why…

Other people have an accent, but not me. And this is not just because I have no accent. I wouldn’t have an accent even if I had one! Accent is a strange thing (as is my reasoning style). No matter the accent you get stuck with – southern, New Yorker, or my valley girl rendition – you feel as if it is the other accents that sound accented to you. Your own accent sounds, well, unaccented, like vanilla, corn flakes, or white bread. Arguments about which person “has an accent” don’t tend to be productive; just a lot of pointing and reiterating the pearl, “No, you’re the one with the accent.” And…

It’s nearing the end of American football season, with the Super Bowl fast approaching. These games involve displays of tremendous strength, agility and heart. What you may not have known is that some of the most talented players out on the field are doing it all with their eyes closed.   Literally.    The American football player Larry Fitzgerald of the Arizona Cardinals made news last year when photographers captured him catching the ball with his eyes closed. He apparently does this all the time. And it is not just Fitzgerald who does this: after just five minutes searching…

How does an outfielder get to the right place at the right time to catch a fly ball? According to a recent article in the Journal of Vision, the "outfielder problem" represents the definitive question of visual-motor control. How does the brain use visual information to guide action? To test three theories that might explain an outfielder's ability to catch a fly ball, researchers programmed Brown University's virtual reality lab, the VENLab, to produce realistic balls and simulate catches. The team then lobbed virtual fly balls to a dozen experienced ball players. "The three existing…

Surgeons from UC Davis Medical Center say they have demonstrated that artificial muscles can restore the ability of patients with facial paralysis to blink, a development that could potentially  prevent corneal ulcers and the blindness that usually follows. Detailed in the January-February issue of the Archives of Facial Plastic Surgery, the development could benefit the thousands of people each year who no longer are able to close their eyelids due to combat-related injuries, stroke, nerve injury or facial surgery. In addition, the technique, which uses a combination of electrode leads…