All posts from Neurophilosophy

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ARTISTS employ a number of different techniques to represent implied motion in two-dimensional works. One of these, commonly used in posters, comics and animation, is the affine shear effect, whereby a moving object is depicted as leaning into the direction of movement. Cartoonists also use action lines to depict movement and speed, with straight lines conveying fast movements and wavy lines conveying slower ones. Motion can also be conveyed by superimposing several images showing the successive positions of a movement, or by a blurred image showing the different positions simultaneously.
The Japanese artist and printmaker Katsushika Hokusai (1760-1849) used a different and innovative technique to convey motion. The simple line drawings in his Manga strips lack all of the commonly-used motion effects, yet give a strong impression of movement by depicting the human body in highly unstable postures. As a new study just published in the journal NeuroReport shows, the figures in the sketches are perceived to be moving because their gravity-defying postures activate regions of the visual cortex that are sensitive to motion.
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THIS is the left cerebral hemisphere of an 18-month-old infant who lived some 800 years ago. Such finds are extremely rare, because nervous tissue is soft and normally begins to decompose soon after death, so this specimen is unique in that it has been far better preserved than any other. Although reduced by about 80% of its original weight, many of its anatomical features have remained intact. The frontal, temporal and occipital lobes have retained their original shape; the gyri and sulci (the grooves and furrows on the surface, respectively labelled G and S, above) are easily recognizable; and amazingly, the temporal contains the identifiable remnants of neurons. 
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I 'M pleased to announce that my post about dinosaur brains and behaviour is featured in Open Lab 2009, the annual anthology of the best science writing on blogs. The book has just been published and is now available at Lulu.com, in hard copy or as a Kindle-compatible PDF.This is the third Neurophilosophy post to be published in this series of books: my posts about the discovery of the neuron and the history of trepanation were included in the 2006 and 2007 editions, respectively.On a related note, this blog has been selected as a finalist in the first annual Research Blogging Awards. I thought it might get into the category of Best Neuroscience Blog, but was very surprised to find it in the Best Research Blog category instead.The expert panel of superstar science bloggers and writers who judged the awards assessed more than 400 nominees to select up to 10 finalists in each of the 20 categories. They consider their selections to be "the best of the best" in science blogging, so it's an honour to be included.Voting for the awards opens on March 4th to all registered users of ResearchBlogging.org, who will be sent an email on that day inviting them to make their choices. If you're not a registerd user, there's still time to register so that you can vote.Many thanks to everyone involved in the awards, and congratulations to all the other finalists. Thanks also to all who put together Open Lab and last, but certainly not least, to you, my readers. Read the comments on this post...

THIS cartoon by Dwayne Godwin, a professor of neurobiology at Wake Forest University School of Medicine, and Jorge Cham, the former researcher and cartoonist who created PhD Comics, has won first place in the informational graphics category of the 2009 International Science and Engineering Visualization Challenge. The New York Times has a slide show of the other winning entries, and today's issue of Science contains a special feature about the competition. Unfortunately, most of the articles are hidden behind a paywall, and although there's an accompanying slide show which contains the whole  infographic (that's just half of it above), the text is too small to read. Posts on brain development:
The growth cone An overview of corticogenesis
The eye tells the brain when to plasticize Cellular "tug-of-war" breaks brain symmetry An eye-opening view of visual development Read the comments on this post...

In February of this year, Jacopo Annese (above), a neuroanatomist and radiologist at the University of California, San Diego travelled to Boston to take delivery of a brain. For Annese, collecting brains is not unusual - he is, after all, director of UCSD's Brain Observatory, which will eventually become a comprehensive library of brains donated by people who had neurological conditions such as Alzheimer's Disease, as well as by healthy people of all ages. This time though, the brain he collected was very special: it belonged to the amnesic patient Henry Molaison,  who for more than 50 years was known in the scientific literature, and to every neuroscience and psychology student, as H.M. Read the rest of this post... | Read the comments on this post...

THE latest issue of MIT Technology Review contains a photo essay by yours truly, called Time Travel Through the Brain, in which I look at how techniques used to investigate the brain have evolved during the 100 year history of modern neuroscience. The essay begins with a drawing by the great Spanish neuroanatomist Santiago Ramón y Cajal, who used the staining method discovered by Camillo Golgi to establish that nervous tissue is composed of cells, then goes on to describe more recent methods such as fibre tracing, Brainbow and various types of microscopy.

The image above is a rotary shadow electron micrograph showing the cytoskeleton of a hippocampal neuron, by Bernd Knöll of the University of Tübingen and Jürgen Berger and Heinz Schwarz of the Max Planck Institute for Developmental Biology. The technique involves freezing the specimen under high pressure in liquid nitrogen, then fracturing it with a blade in an ultra-cooled vacuum chamber to strip off the membrane. During fracture, the specimen stage rotates; as it does so, platinum and carbon are deposited onto it from a pair of electrodes, to produce a metallic three-dimensional replica of the cell interior. Read the comments on this post...

USING an inventive new method in which mice run through a virtual reality environment based on the video game Quake, researchers from Princeton University have made the first direct measurements of the cellular activity associated with spatial navigation. The method will allow for investigations of the neural circuitry underlying navigation, and  to a better understanding of how spatial information is encoded at the cellular level.
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THIS image by Dominik Paquet of Ludwig-Maximilians-Universität in Munich is one of the winners of the 2009 Nikon Small World Photomicrography competition. It's a confocal fluoresence microscopy image of zebrafish larvae expressing a mutant form of human Tau protein, which forms the neurofibrillary tangles that are a pathological hallmark of Alzheimer's Disease. The work is described in this recent paper.
Below are two more images from the competition. Read the rest of this post... | Read the comments on this post...

REMOTE-CONTROLLED insects may sound like the stuff of science fiction, but they have already been under development for some time now. In 2006, for example, the Defense Advanced Research Projects Agency (DARPA, the Pentagon's research and development branch) launched the Hybrid Insect Micro-Electro-Mechanical Systems program, whose ultimate aim is to turn insects into unmanned aerial vehicles.Such projects provide proof of principle, but have met with limited success. Until now, that is. In the open access journal Frontiers in Integrative Neuroscience, a team of electrical engineers led by Hirotaka Sato of the University of California, Berkeley, report the development of an implantable radio-controlled neural stimulating device, with which they demonstrate, for the very first time, the accurate control of flight in freely flying insects.
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THIS short film clip shows two images of the same scene. Watch it carefully, and see if you can spot the subtle differences between them. As you watch, your eyes will dart back and forth across the images, so that you can perceive the most important features. And even though you might not be consciously aware of the differences, your brain will have picked up on them. This implicit form of remembering is referred to as relational memory; in this case, the brain is encoding the perceptual associations between items in the image. And recent studies have shown that relational memory retrieval is evident in eye movements - even if you did not explicitly detect the change in the second image, you will, without knowing it, have spent more time looking at the changed area than at others.
However, it was unclear whether relational memory retrieval involved the same neural substrates as retrieval of other, more familiar types of memory, such as your recollection of what you had for breakfast this morning, or what you did last weekend. This latter form of memory (known as declarative memory) is well known to involve the hippocampus, a brain structure buried deep within the brain, in the medial temporal lobe. Now researchers from the University of California, Davis, report that unconscious retrieval of relational memory also involves the hippocampus, and that activity in this part of the brain can predict the eye movements associated with expression of this type of memory.

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THIS weird and wonderful creature is the star-nosed mole (Condylura cristata), a small, semi-aquatic mammal which inhabits the low wetlands of eastern North America. Like other moles, it ekes out an existence in a network of narrow underground tunnels, and digs shallow surface tunnels where it forages for insects, worms and molluscs. Living as it does in almost complete darkness, the star-nosed mole has poorly developed eyes, and is virtually blind. Instead, it relies heavily on its remarkable star-shaped nose. This organ enables the star-nosed mole to decide whether something is edible with astonishing speed - in fact, it recently entered the Guinness Book of Records as the world's fastest forager - and also to sniff out food underwater. Read the rest of this post... | Read the comments on this post...