ATTENTION ACTS AS VISUAL 'GLUE'
Paying attention seems to be the critical factor in the brain's efforts to join different bits of visual information into a coherent picture of an object or a scene. In a series of trials, Vanderbilt University researchers asked subjects to view pairs of objects displayed on a computer screen. For each image, subjects were asked to concentrate on shape only, color only or both shape and color while researchers monitored their brain activity with magnetic resonance imagery or MRI scans. Whenever the subjects focused on more than one object at a time, activity in the parietal region of their brains increased significantly. "This provides strong evidence in favor of the theory that spatial attention is the binding glue that the brain uses to integrate visual objects," researchers said, but added the findings do not rule out other possibilities. "It is practically certain that the brain uses several mechanisms to solve this fascinating problem."
ONE GENE, TWO DISEASES?
University of Michigan researchers said they have found a gene associated with retinitis pigmentosa or RP, which also causes a form of macular degeneration, or MD. The gene, called RPGR, links directly to a form of early-onset MD that primarily affects men. The researchers discovered the gene in a study of 10 males, all from the same family, who had the early-onset form of the disease. The men were affected as teens or young adults rather than at the typical age of 60 or older. Researchers said the finding will help understand the mechanisms that protect or destroy central and peripheral vision. MD causes the loss of central vision needed for such activities as reading and driving. Peripheral or side vision generally is not affected. RP first affects peripheral and night vision and eventually leads to total blindness. There is no cure for either disease.
BIRDS CLEARED OF EPIDEMIC BLAME
Researchers from several institutions have concluded birds did not cause the 1918 influenza pandemic that killed up to 40 million people worldwide. The researchers examined specimens from the Smithsonian Institution's collection of liquid-preserved birds. When they isolated and genetically sequenced samples of the flu virus hemagglutinin, or HA, from birds captured between 1915 and 1919 and compared them with the 1918 pandemic version of the virus, they concluded it "was not derived directly from an avian source." Modern techniques for conducting genetic analyses on animal specimen collections are taking on "tremendous scientific importance," the researchers said, enabling science to solve some of the "mysteries about our past." The 1918 epidemic became extremely lethal because the HA strain of the virus was so new no one had developed immunity to it. The disease swept the globe within six months, killing 10,000 or more people a week in some U.S. cities.
BLACK HOLES IN COLLISION
Australian and American astronomers have produced a mathematical model that mimics one of the more spectacular phenomena in the universe -- super-massive black holes that collide during the merger of galaxies. Their calculations show when two black holes merge, the crunch suddenly switches direction of the particle jets that shoot out along the larger black hole's spin axis. The phenomenon is large enough to observe with radio telescopes. Both the old and new jet streams appear, making a galaxy appears X-shaped. Supermassive black holes have been found in the center of almost every galaxy, the researchers said, weighing a few million to a few billion times the size of our sun. They estimate a black hole collision occurs about once every billion years, meaning two of the cosmic monsters are slamming together somewhere in the universe about once each year.
(Editors: For more information on ATTENTION, contact David F. Salisbury at 615-343-6803 or [email protected]. For EYE GENE, Betsy Nisbet at 734-647-5586 or [email protected]. For FLU, Michele Urie at 202-786-2950 or [email protected]. For BLACK HOLES, Joseph Blumberg AT 732-932-7084 x652 or [email protected])
