AFTER four years here at ScienceBlogs.com, Neurophilosophy is moving to a new home. As of today, it will be hosted by The Guardian.
During its time here, the blog has grown from strength to strength. It has received over 2.5 million page views, was featured regularly on the New York Times science page, and has been translated into about a dozen languages. It has also enabled me to earn a living as a freelance science writer for the past two years.
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, show that echolocation engages regions of the brain that normally process vision.
Skull of Hadrocodium wui. (Image courtesy of Mark Klinger and Zhe-Xi Luo, Carnegie Museum of Natural History)
THE question of how mammals evolved their exceptionally large brains has intrigued researchers for years, and although many ideas have been put forward, none has provided a clear answer. Now a team of palaeontologists suggests that the mammalian brain evolved in three distinct stages, the first of which was driven by an improvement in the sense of smell. Their evidence, published in tomorrow's issue of Science, comes from two fossilized skulls, each measuring little more than 1cm in length.
THE patterns of brain waves that occur during sleep can predict the likelihood that dreams will be successfully recalled upon waking up, according to a new study published in the Journal of Neuroscience. The research provides the first evidence of a 'signature' pattern of brain activity associated with dream recall. It also provides further insight into the brain mechanisms underlying dreaming, and into the relationship between our dreams and our memories.
Cristina Marzano of the Sleep Psychophysiology Laboratory at the University of Rome and her colleagues recruited 65 students, selected on the basis of their sleeping habits. All of them had a regular sleep 'routine', going to bed at around the same time, and sleeping for an average of seven-and-a-half hours, every night. For the study, the participants slept for two consecutive nights in a sound-proof, temperature-controlled room in the lab. They were left to sleep uninterrupted on the first night, so that they would get accustomed to the new surroundings.
THE United States military funded research into using networks of 'spy crows' to locate soldiers who are missing in action, and extended the work to see if the birds might be useful in helping them to find Osama bin Laden. The idea may seem far-fetched, but unlike some military research programs (such as the Stargate remote-viewing program) it is actually based on sound science.
YOUR brain has a remarkable ability to extract and process biological cues from the deluge of visual information. It is highly sensitive to the movements of living things, especially those of other people - so much so that it conjures the illusion of movement from a picture of a moving body. Although static, such pictures trigger dynamic representations of the body, 'motor images' containing information about movement kinematics and timing. Researchers at the Institute of Cognitive Neuroscience in London now show that biological motion is processed unconsciously, and that the speed of apparent motion alters the perception of time.
Ernst Haeckel's Kunstformen der Natur (Artforms of Nature) was a landmark in biological illustration. Published in 1904, it was lavishly illustrated with 100 exquisitely detailed lithographic plates, including this one, showing nine different species of cubomedusae, or box jellyfish.
It has been known, since around the time that Haeckel's masterpiece was published, that box jellyfish have a unique visual system which is more sophisticated than that of other jellyfish species. They boast an impressive set of 24 eyes of four different types, which are clustered within bizarre sensory appendages that dangle from the cube-shaped umbrella. The known light-guided behaviours of these organisms are, however, relatively simple, so exactly why they possess such an elaborate array of eyes was somewhat puzzling.
A group of Scandinavian researchers working in the Carribean now report that one of the box jelly's eye types is highly specialized to peer up towards the water surface at all times, so that it can use terrestrial landmarks to navigate towards its prey.
THE human gut contains a diverse community of bacteria which colonize the large intestine in the days following birth and vastly outnumber our own cells. These intestinal microflora constitute a virtual organ within an organ and influence many bodily functions. Among other things, they aid in the uptake and metabolism of nutrients, modulate the inflammatory response to infection, and protect the gut from other, harmful micro-organisms. A new study by researchers at McMaster University in Hamilton, Ontario now suggests that gut bacteria may also influence behaviour and cognitive processes such as memory by exerting an effect on gene activity during brain development.
Jane Foster and her colleagues compared the performance of germ-free mice, which lack gut bacteria, with normal animals on the elevated plus maze, which is used to test anxiety-like behaviours. This consists of a plus-shaped apparatus with two open and two closed arms, with an open roof and raised up off the floor. Ordinarily, mice will avoid open spaces to minimize the risk of being seen by predators, and spend far more time in the closed than in the open arms when placed in the elevated plus maze.
I visited Vilayanur S. Ramachandran's lab at the University of California, San Diego recently, and interviewed him and several members of his lab about their work. Rama and I talked, among other things, about the controversial broken mirror hypothesis, which he and others independently proposed in the early 1990s as an explanation for autism. I've written a short article about it for the Simons Foundation Autism Research Initiative (SFARI), and the transcript of that part of the interview is below. I also wrote an article summarizing the latest findings about the molecular genetics of autism, which were presented in a symposium held at the Society for Neuroscience annual meeting last November.
