At Rest, Your Brain Runs in Screensaver Mode
Your brain's visual centers remain active when your eyes are closed and even when you sleep, studies have shown. But it's a different type of activity, one not fully understood.
A new study sheds light. In both situations - resting with eyes closed or sleeping - electrical activity continues in the brain, but the activity is represented by slow electrical fluctuations, rather than the bursts of activity that occur when you're awake with eyes wide open. The resting oscillations, as the scientists call them, were found to be most pronounced during deep sleep, as might be expected.
The slow fluctuation pattern can be compared to a computer screensaver, say the researchers at the Weizmann Institute.
Though the newfound activity's function is unclear, the researchers have a couple ideas:
Perhaps neurons, like philosophers, must "think" in order to be; neuron survival, the idea goes, would require a constant state of activity. Or maybe the minimal level of activity enables a quick start when an outside stimulus is presented, something like a getaway car with the engine running, the researchers suggest.
These new ideas differ starkly from how scientists thought all this worked. "In the old approach, the senses are 'turned on' by the switch of an outside stimulus," explained Weizmann Institute neurobiology student Yuval Nir, who worked on the study. "This is giving way to a new paradigm in which the brain is constantly active, and stimuli change and shape that activity."
This different type of brain activity could also explain why most people don't constantly experience hallucinations or hear voices while they rest, the researchers suggest.
Previous investigations of the resting brain typically relied on brain scans and told only part of the story. The new study used data collected from epilepsy patients who underwent extensive testing, including measurements of neuronal pulses in various parts of their brains during diagnosis and treatment.
The method suggests ways of probing the brains of young children or patients in a coma - anyone who is not alert or whose cooperation might prove challenging.
"The use of clinical data enabled us to solve a riddle of basic science in a way that would have been impossible with conventional methods," said lead researcher Rafael Malach, a professor at the institute. "These findings could, in the future, become the basis of advanced diagnostic techniques."
The research, funded by several institutions and foundations, is detailed in the journal Nature Neuroscience.
- Original Story: At Rest, Your Brain Runs in Screensaver Mode
Boys With Unpopular Names More Likely to Break Law
Boys in the United States with common names like Michael and David are less likely to commit crimes than those named Ernest or Ivan.
David E. Kalist and Daniel Y. Lee of Shippensburg University in Pennsylvania compared the first names of male juvenile delinquents to the first names of male juveniles in the population. The researchers constructed a popularity-name index (PNI) for each name. For example, the PNI for Michael is 100, the most frequently given name during the period. The PNI for David is 50, a name given half as frequently as Michael. The PNI is approximately 1 for names such as Alec, Ernest, Ivan, Kareem, and Malcolm.
Results show that, regardless of race, juveniles with unpopular names are more likely to engage in criminal activity. The least popular names were associated with juvenile delinquency among both blacks and whites.
The findings, announced today, are detailed in the journal Social Science Quarterly.
While the names are likely not the cause of crime, the researchers argue that "they are connected to factors that increase the tendency to commit crime, such as a disadvantaged home environment, residence in a county with low socioeconomic status, and households run by one parent."
"Also, adolescents with unpopular names may be more prone to crime because they are treated differently by their peers, making it more difficult for them to form relationships," according to a statement released by the journal's publisher. "Juveniles with unpopular names may also act out because they consciously or unconsciously dislike their names."
The findings could help officials " identify individuals at high risk of committing or recommitting crime, leading to more effective and targeted intervention programs," the authors conclude.
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- Original Story: Boys With Unpopular Names More Likely to Break Law
Scientists find new creatures of Australian deep
SYDNEY – Scientists said Sunday they had uncovered new marine animals in their search of previously unexplored Australian waters, along with a bizarre carnivorous sea squirt and ocean-dwelling spiders.
One of Australia's deepest residents a carnivorous sea squirt, or ascidian, standing half a meterA joint US-Australian team spent a month in deep waters off the coast of the southern island of Tasmania to "search for life deeper than any previous voyage in Australian waters," lead researcher Ron Thresher said.
What they found were not only species new to science -- including previously undescribed soft corals -- but fresh indications of global warming's threat to the country's unique marine life.
"Our sampling documented the deepest known Australian fauna, including a bizarre carnivorous sea squirt, sea spiders and giant sponges, and previously unknown marine communities dominated by gooseneck barnacles and millions of round, purple-spotted sea anemones," Thresher said.
Using a submersible car-sized robot named Jason, the team explored a rift in the earth's crust known as the Tasman Fracture Zone, a sheer two kilometre (1.24 mile) drop to 4,000 metres (13,200 feet) below the ocean's surface.
Blogging on board the ship, researcher Adam Subhas said the team witnessed some "cool biology" as they descended the fracture, including the sea squirt, which he described as "basically an underwater Venus fly trap, but much bigger."
The sea squirt, also known as an ascidian, stands 50 centimetres tall on the sea floor at a depth of just over 4,000 metres. It traps prey in its funnel-like front section if they touch it when they swim past.
"The geology was fascinating too -- the sediment was incredibly fine and lightly packed; it made me think of powder snow," Subhas wrote.
Fossil coral fields were found, dating back more than 10,000 years. Thresher said samples taken would provide ancient climate data for use in global warming projections.
"Modern-day deep-water coral reefs were also found, however, there is strong evidence that this reef system is dying, with most reef-forming coral deeper than 1,300 metres newly dead," he said.
Though close analysis of samples was still required, Thresher said modelling suggested ocean acidification could be responsible.
"If our analysis identifies this phenomenon as the cause of the reef system's demise, then the impact we are seeing now below 1,300 metres might extend to the shallower portions of the deep-reefs over the next 50 years, threatening this entire community," he said.
Rising sea temperatures are blamed on global warming caused by the build-up in the atmosphere of greenhouse gases such as carbon dioxide -- which is also blamed for higher acidity in sea water.
A UN report warned in 2007 that Australia's Great Barrier Reef, described as the world's largest living organism, could be killed by climate change within decades.
The World Heritage site and major tourist attraction, stretching over more than 345,000 square kilometres (133,000 square miles) off Australia's east coast, could become "functionally extinct", the report said.
New Catfish Species Climbs Rocks
A previously unknown species of climbing catfish has been discovered in remote Venezuela, and its strange traits are shaking the evolutionary tree for these fish.
The newfound catfish, Lithogenes wahari, shares traits with two different families of fish - Loricariidae (armored catfishes) and Astroblepidae (climbing catfishes). It has bony armor that protects its head and tail, and a grasping pelvic fin that helps it to climb vertical surfaces such as rocks.
These characteristics in L. wahari suggest to ichthyologists Scott Schaefer of the American Museum of Natural History in New York and Francisco Provenzano of the Universidad Central de Venezuela that the common ancestor of the Loricariidae and Astroblepidae probably could grasp and climb rocks with its tail and mouth. Fish in both families, as well as the new catfish, have sucker mouths.
The unusual catfish caught the team's attention 20 years ago in Caracas. An anthropologist, Stanford Zent of the Instituto Venezolano de Investigaciones Cientificas, working in the remote state of Amazonas collected samples of local foods and brought them to the Instituto de ZoologÃca for identification.
"The fish was so strange in morphology that it did not fit into any taxonomic category that we were aware of," Schaefer said. "But it looked like it was run over by a truck. We needed better specimens."
It took years to pin down where the fish was found, but the team collected L. wahari after several trips further into the headwaters of the RÃo Cuao, a tributary of the RÃo Orinoco. They literally picked 84 specimens off of rocks.
The new samples of L. wahari confirmed that the species is a member of a group that bridges two catfish families. Bony plates on its head and tail, plus other features, link the species to the Loricariidae, the widespread and successful family of fully armored catfishes.
But L. wahari also has a specialized pelvic fin that decouples from its body and moves backward and forward independently. This feature - used in combination with a grasping mouth to move like an inchworm up rocks - is otherwise found only in a family of climbing catfish restricted to the Andes, the Astroblepidae. Climbing could be an advantage to these fishes because of the irregular and sometimes high-flow of streams in higher elevations. When the scientists found the new species, the water level was so low that the fish were literally picked off of rocks.
This evolutionary arrangement suggests that the common ancestor to both families probably inhabited upland, rather than lowland, streams of the Amazon and Orinoco river basins, where most of the family diversity is currently found.
"We see new fish species all the time, but when you also get new information about the biological history of a group, it's the most fun," Schaefer said. "The question is whether the grasping pelvis and climbing behavior evolved once or if it was independently acquired in these groups. I don't think it evolved twice, although there are slight anatomical differences - so the jury is still out."
The paper is published in the journal American Museum Novitates, and the research was supported by the Constantine S. Niarchos Scientific Expedition Fund and the National Science Foundation.
