neuroscience
neurophilosophy | July 4, 2008Foreign accent syndrome (FAS) is a neurological condition that is acquired following a stroke or some other form of brain injury. It occurs as a result of damage to the brain's speech motor centres, so that syllables are mispronounced, making one sound as if they are speaking their native language in a foreign accent.
FAS is extremely rare, with only around 50 reported cases since 1941. Two of these were reported in stroke victims in recent years: Linda Walker, a 62-year-old woman from Newcastle, began speaking in an accent that was described as a mixture of Jamaican, Canadian and Slovakian,…
edyong | July 4, 2008There can be few events more devastating for a parent than cot death - the sudden and unexpected death of a baby. Cot death is more formally known as Sudden Infant Death Syndrome (SIDS) and it is an apt title, for affected babies often seem outwardly healthy and show no signs of suffering. Studies have suggested that things like passive smoke and breastfeeding can affect the risk of SIDS but the underlying biology behind the syndrome is a mystery, as is the cause of death in most cases.
But it's a mystery that's slowly being solved. The latest and most intriguing clue comes from Enrica…
neurophilosophy | July 3, 2008Hollywood actress Sharon Stone hit the headlines recently, following her remarks that the massive earthquake which struck south-west China on May 12th could have occurred as a result of "bad karma" produced by Beijing's policy towards Tibet.
Now, according to LA Times celebrity gossip blog The Dish Rag, animal rights group PETA has offered Stone a free brain scan to determine whether her apparent lack of empathy can be attributed to frontal lobe damage.
In a letter addressed to the actress, dated July 1st, PETA president Ingrid Newkirk writes:
Scientific studies suggest that the prefrontal…
neurophilosophy | July 3, 2008The latest Seed Salon features highlights from an interesting discussion between Tom Wolfe and Michael Gazzaniga, one of the founders of cognitive neuroscience, who is best known for the work he carried out with Roger Sperry on split brain patients.
Gazzaniga and Wolfe discuss, among other things, the implications of neuroscience for our concept of free will. The transcript of the whole discussion has just been published in the current issue of Seed, and is now available online.
I love this anecdote from the transcript, about how Jose Delgado controlled an angry bull by electrical…
neurophilosophy | July 2, 2008During a cerebrovascular accident (or stroke), the blood supply to part of the brain is interrupted. This is often caused by a blood clot which blocks an artery that carries blood to the brain. Consequently, neurons in the affected region of the brain die because they are deprived of oxygen.
Stroke has several characteristic symptoms: slurred speech, paralysis and weakness on the right side of the body, and weakness and drooping of the face. These typically develop within minutes, and occur because stroke often affects the motor cortex in the left hemisphere, which controls the movements of…
neurophilosophy | July 1, 2008In a very cool paper published yesterday in the open access journal PLoS Biology, an international team of researchers report that they have produced the most detailed and comprehensive map yet of the connections in the human cerebral cortex.
The cerebral cortex contains hundreds of billions of cells organized into thousands of discrete functional modules which act in parallel to generate all human behaviours and cognitive processes.
The new study uses neuroimaging to visualize more than 14,000 connections between nearly 1,000 of these modules, and reveals what the researchers call the brain'…
neurophilosophy | June 30, 2008We are being constantly bombarded with news stories containing pretty pictures of the brain, with headings such as "Brain's adventure centre located". Journalists now seem to refer routinely to functional magnetic resonance imaging (fMRI) as "mind reading", and exaggerated claims about its powers abound, as do misleading, irresponsible and downright ridiculous stories about the technology.
Take, for example, this article by Jeffrey Goldberg in The New Atlantic:
The preliminary findings began to arrive a few days later, in a series of e-mails..."Carter: big amygdala response on both sides…
purepedantry | June 27, 2008There is a must-read paper in Nature about the limits of functional MRI as an experimental tool by one of its pioneers, Nikos Logothetis. (Also discussed by Jonah and Vaughan.)
This paper is pretty technical, but Logothetis hits the important points of what it is we think we are actually measuring using the fMRI. Also, he notes that the difficulty in interpreting fMRI data lies in the fact that you have to make assumptions about network architecture that may or may not be true. Other experiments are required to confirm the validity of these assumptions.
Here is his good summary of the…
clock | June 26, 2008Marc Dingman is touching on my own favorite topic: It's All About Timing: Circadian Rhythms and Behavior
And SciCurios goes only millimeters below the suprachiasmatic nucleus: Diabetes Insipidus as a Sequel to a Gunshot Wound of the Head
Both posts well worth your time.
neurophilosophy | June 26, 2008Nature News has an interesting article by Philip Ball about a dancing cockatoo named Snowball:
Aniruddh Patel of the Neurosciences Institute in La Jolla, California, and his colleagues say that Snowball's ability to shake his stuff is much more than a cute curiosity. It could shed light on the biological bases of rhythm perception, and might even hold implications for the use of music in treating neurodegenerative disease.
Below is a film clip of Snowball getting his groove on.
neurophilosophy | June 25, 2008Researchers from the Computational Neuroimaging Laboratory at New York University recently carried out a study of the effects of films on viewers' brains.
Hasson et al scanned the brains of 45 participants whilst they watched scenes from a number of films and television programmes. Not surprisingly, they found that all the scenes activated numerous and diffuse regions of the cerebral cortex - visual areas in the occipital lobes, auditory and language centres in the temporal lobes, and so on.
The data obtained were then subjected to a newly-developed statistical method called inter-subject…
neurophilosophy | June 24, 2008The forthcoming issue of The New Yorker contains a fantastic article by surgeon and writer Atul Gawande about the neurobiology of itching.
The article begins with the extraordinary case of a patient known as M., whose itch, which occurred following an episode of shingles, became so unbearable that one morning she awoke to find that she had scratched through her skull and into her brain while she slept.
Gawande continues with a brief history of theories about itching - it was long considered to be a mild form of pain, but came to be recognized as a distinct sensation, following experimental…
neurophilosophy | June 24, 2008General anaesthetics activate a heat-sensitive protein found in pain pathways and may exacerbate post-operative pain, according to a new study published online yesterday in the Proceedings of the National Academy of Sciences.
Anaesthetics suppress activity of the central nervous system, leading to a reversible loss of consciousness. The suppression of neural activity is thought to occur by the actions of the anaesthetic on the GABA receptor, which is normally activated by gamma-aminobutyric acid, the principal inhibitory neurotransmitter in the brain.
Every year, more than 100 million…
neurophilosophy | June 24, 2008Here are some more new members of the ever-growing online neuroscience community:
The Brain and the Sky
Illusion Sciences
N-Cog-Neato!
Neurophilia
Neurotonics
neurophilosophy | June 23, 2008At the Neuroanthropology blog, Daniel rounds up the usual suspects of neuroscience and psychology bloggers for the 48th edition of Encephalon.
This time, the carnival includes entries on everything from visual illusions and the neurobiology of language evolution, to the ethnography of Second Life and a new study which purports to show that mirror neurons control erections.
neurophilosophy | June 23, 2008I've just discovered that the book Eye, Vision and Brain, by Nobel Prize winner David Hubel, is available online in its entirety.
Hubel is a neurophysiologist who performed some classic experiments with Torsten Wiesel, beginning in the late 1950s, on the development and functional properties of the visual system.
Using microelectrodes inserted into the primary visual cortex of anaesthetized cats, Hubel and Wiesel characterized the responses of cells to various visual stimuli. They found groups of cells which responded selectively to lines of a specific orientation, others which responded to…
neurophilosophy | June 21, 2008The Smithsonian Institution's new Flickr photostream contains nearly 900 photographs, including a large set of portraits of scientists and inventors, among them Charles Darwin, Albert Einstein and Marie Curie and Walther Nernst (above).
Nernst was a German physical chemist who in 1888 derived an equation which can be used to calculate an ion's equilibrium potential, i.e. the voltage at which its movements in one direction across a membrane are equal to its movements in the other.
The Nernst equation is of importance to electrophysiologists, because the electrical properties of neurons are…
neurophilosophy | June 20, 2008The 19th century histologists who discovered the neuron also found that the nervous system contains another type of cell. They assumed that the role of these other cells was to provide structural support for neurons, and so named them glia (meaning "glue"). Subsequently, investigators focused their attention on neurons, which they considered to be the key players in brain function, and glia were largely ignored.
The view that glia play a secondary role in brain function persisted for about a hundred years. Recently, however, this has begun to change, and it is now clear that glia play…
edyong | June 20, 2008
The differences between heterosexual and homosexual people are as much the subject of fascinating science as they are a source of social debate. And in many cases, the former can help to inform the latter. There is now plenty of research which shows that a person's sexual orientation, far from being a phase or a lifestyle choice, is a reflection of fixed properties of their brain that develop at an early age.
A new study adds new weight to this evidence by using brain-scanning technology to look at the differences between the brains of gay and straight people. Ivanka Savic and Per Lindstrom…
neurophilosophy | June 18, 2008This cartoon, found at Paleo-Future, accompanied a short article from the August 28th, 1949 edition of the San Antonio Light:
CHICAGO, Aug. 27 - (AP) - Some day composers won't write music, and musicians won't play it - yet fans will enjoy it in never-before-heard perfection.
The composer or artist will simply project it by brain waves - "thought transference," says Raymond Scott.
BRAIN WAVES
This man, who thinks in terms of electronics and music, thinks that is all quite possible. Scott said in an interview:
"Brains put out electrical waves. I wouldn't be at all surprised if some day it…