neurophilosophy | November 28, 2007
It is said that the camera never lies, but according to new research published in the journal Applied Cognitive Psychology, the camera not only lies, but those lies can lead to the creation of false memories.
In the study, which was led by Dario Sacchi of the University of Pagua and designed by veteran memory researcher Elizabeth Loftus, participants viewed photographs of the 1989 Tiananmen Square protest in Beijing or the protest against the Iraq war which took place in Rome in 2003.
Some of the participants were presented with digitally altered photographs, while others were shown…
neurophilosophy | November 28, 2007Neurologist and neuroscientist Vilayanur S. Ramachandran is giving a talk at the Royal Society in London tonight. Entitled Nature and nurture in brain function: clues from synesthesia and phantom limbs, the talk begins at 6.30pm GMT.
The lecture is free and does not require a ticket or advance booking, so if you're in London it's well worth attending. If you can't make it, the talk will be webcast live. I'll be there, as Ramachandran has been somewhat of an inspiration to me.
[Thanks Vaughan]
neurophilosophy | November 27, 2007
This image of the brainstem of a Brainbow mouse, by Jean Livet of Harvard University, has just been awarded 1st prize in the 2007 Olympus Bioscapes International Digital Imaging Competition.
neurophilosophy | November 27, 2007A lengthy article in last weekend's Washington Post Magazine discusses the work of Michael Mithoefer, a psychiatrist at the Medical University of South Carolina (MUSC) who has almost completed the first phase of a clinical study into the use of ecstasy as a therapeutic tool for post-traumatic stress disorder.
Ecstasy (MDMA, or 3,4-methylenedioxy-N-methylamphetamine) is a psychedelic and a stimulant which acts by inhibiting the reuptake of serotonin, and, to a lesser extent, of dopamine and noradrenaline. It is illegal in most countries (it is classified as a Class A drug in the U.K. and a…
neurophilosophy | November 25, 2007
I'm back in London after a hectic - but fantastic - week in Egypt. Of the hundreds of photographs that I took on the trip, this is one of my favourites. It shows part of old Cairo as seen through a peephole in the minaret of a medieval mosque. I'll be posting more of my photos (of both this extraordinary city and of Alexandria) at weekends.
neurophilosophy | November 22, 2007[Introduction|Part 2|Part 3]
The three studies discussed here make important contributions to our understanding of axon guidance. Lopez-Bendito et al describe a novel guidance mechanism involving tangentially migrating GABAergic interneurons. These cells migrate ventrally from the LGE to form a permissive corridor through the MGE, a region that is otherwise non-permissive for TCAs.
The corridor is fully formed by the time TCAs reach the ventral aspect of the MGE. This is therefore a means by which the presentation of guidance cues can be regulated both spatially and temporally. This may be…
neurophilosophy | November 21, 2007[Introduction|Part 2|Discussion]
Tojima et al (2007) find that the growth cone's response to attractive guidance cues requires asymmetrical vesicle transport and exocytosis. They cultured dorsal root ganglion (DRG) cells from embryonic chicks, and produced localized elevations in calcium ion concentration on one side of the growth cone by photolytic release of the caged calcium ion compound DMNT-EDTA. In cells cultured on a substrate of cell adhesion molecule L1, this causes calcium-induced calcium release (CICR), and elicits a turning response in the direction of the calcium signal. In…
neurophilosophy | November 20, 2007[Introduction|Part 3|Part 4]
Lopez-Bendito et al (2006) show that pathfinding of thalamocortical axons (TCAs) requires the formation of a permissive corridor through non-permissive territory, and that this corridor is generated by cells which undergo a tangential migration from the lateral ganglionic eminence (LGE).
TCAs arise in the dorsal thalamus, and follow a stereotyped pathway into the developing neocortex. Initially, they are repelled by Slit 1 and Slit 2 expressed in the hypothalamus. They extend rostrally into the telencephalon and turn sharply before extending dorsolaterally to…
neurophilosophy | November 19, 2007
Dylan T. Burnette/ Nikon Small World.
The remarkable specificity of neuronal connectivity depends on accurate axon pathfinding during development. Pathfinding involves the detection of guidance cues in the environment by the growth cone, a motile chemotactic structure at the leading tip of the extending axon.
The growth cone was discovered over 100 years ago by Santiago Ramon y Cajal, the father of modern neuroscience. Cajal's description of the growth cone (or cono de crecimiento) has not been bettered:
From the functional point of view, one might say that the growth cone is like a…
neurophilosophy | November 16, 2007I'm off to Egypt later on today to attend my cousin's wedding. I probably won't have access to the internet for the 8 days that I'm there, so I've scheduled some posts for next week: the essay I've just submitted for my Masters will be appearing in a series of four posts, starting on Monday.
Otherwise, there'll be no activity here. I won't even be approving any comments that are posted, but don't let that stop you from commenting, as I'll moderate them all as soon as I get back. Meanwhile, feel free to browse my archives, and don't forget to visit Brain in a Vat this coming Monday fro the…
neurophilosophy | November 16, 2007
In his Insect Lab Studio, sculptor Mike Libby customizes real insects with parts from antique pocketwatches and electronic components from old circuit boards. Here, he describes how the idea first came to him:
One day I found a dead intact beetle. I then located an old wristwatch, thinking of how the beetle also operated and looked like a little mechanical device and so decided to combine the two. After some time dissecting the beetle and outfitting it with watch parts and gears, I had a convincing little cybernetic sculpture. I soon made many more with other found insects and have been…
neurophilosophy | November 16, 2007
Synaesthesia is a condition in which stimuli of one type evoke sensations in another sensory modality. For example, hearing particular sounds might evoke strong sensations of colour or (more rarely) words might evoke strong tastes in the mouth.
In The Hidden Sense, social scientist Cretien van Crampen investigates synaesthesia from an artisitic and scientific perspective. He interviews a number of synaesthetes, and finds that none of them considers their condition to be an impairment. He also describes the profound influence that synaesthesia has had on artists such as Kandinsky and van Gogh…
neurophilosophy | November 15, 2007
At the Society for Neuroscience meeting in San Diego last week, a group of researchers presented data on a speech prosthesis which they say could soon enable a paralyzed man to talk again.
The device, which consists of 3 gold recording wires, was implanted into the brain of Eric Ramsey, who was completely paralyzed in a car accident 8 years ago. Ramsey is said to be "locked in" - he is fully conscious but is unable to communicate in any way.
The implant is located 6mm below the surface of Ramsey's brain, in a part of the left premotor cortex, where it records the activity of 41 cells…
neurophilosophy | November 15, 2007From KMBC:
Clay County sheriff's deputies said David Theiss, of Kansas City, possessed a Colorado River toad with the intention of using it as a hallucinogenic.
Experts said it's possible to lick the toad's venom glands to achieve psychedelic effects.
Most pet stores don't sell the Colorado River toad because the venom can sicken humans and kill household animals.
"People used to do it all the time, but it got faded out awhile, but came back as a fad. Not a smart one," animal expert Danny Snyder told KMBC's Dion Lim. "The toxins in it can kill a lot of stuff."
Authorities said this is the…
neurophilosophy | November 14, 2007
An individual ant is quite insignificant, but a large group of ants can do quite remarkable things. Likewise, neurons evolved to communicate with each other, and are quite useless except when connected to a network of other neurons.
I've always liked to use the ant colony as an anology for brain function. According to this article about swarm intelligence by Carl Zimmer, it may be more than just an anology:
By studying army ants -- as well as birds, fish, locusts and other swarming animals -- Dr. Couzin and his colleagues are starting to discover simple rules that allow swarms to work so…
neurophilosophy | November 13, 2007
Regular readers will know that I rarely write about politics. But this post is an exception, as it is written in memory of my father, who died on this day 7 years ago. That's my father on the left, with the Palestinian leader Yasser Arafat, who died almost exactly four years later.
Some 14 months after Arafat's death, in January 2006, the Palestinians elected as their leaders the Islamist group Hamas (Harakat al-Muqawamah al-Islamiyya, or the Islamic Resistance Movement).
The election was democratic, in the real sense of the word. Unfortunately, however, the Palestinians elected the…
neurophilosophy | November 12, 2007Today's Independent contains an extract from Taking the Proverbial, a book about the psychology of proverbs by Geoff Rolls.
The extract includes sections from the book which discuss the proverbs "An elephant never forgets" and "Practice makes perfect". The section about the first includes a nice summary of some animal cognition studies, and the second includes mention of the neuropsychology of motor learning and performing in front of an audience.
This part however, from the section on elephants' memory, sounds familiar:
Whether [elephants] deserve their status as the memory experts of the…
neurophilosophy | November 9, 2007
The Los Angeles Times reports on "Robo-moth", a cleverly designed contraption, built from cheap off-the-shelf parts, which was presented at the Society for Neuroscience meeting in San Diego earlier this week.
Robo-moth is a 6-inch-tall wheeled robot to which attached tobacco horn moth has been attached. A microelectrode inserted into the insect's brain records the activity of a single visual motion detection neuron, which exhibits directional selectivity and which is involved in steadying the visual field during flight.
The moth is immobilized inside a cylinder covered with vertical stripes…
neurophilosophy | November 9, 2007
The cover of the current issue of Neuron features this brainland map, by Sam Brown, a cartographer based in New Zealand. Printed A3, A2 and A1 sized copies of the map can be purchased from Unit Seven.
...created from a reference photo of a real human brain which was used to build the 3D terrain. This digital elevation model was then used to create contour line data, relief shading and to plan where the roads and features should be placed for map compilation. Real New Zealand public domain data was then added for the surrounding islands.
I've just written an essay about Axon Turning…
neurophilosophy | November 9, 2007Biological anthropologist Greg Laden and theoretical physicist Dave Bacon have just joined ScienceBlogs. Both of these blogs are fantastic, so go and check them out.
If you're a regular reader of this blog, it's safe to say that you're interested in neurobiology, so you'll probably want to read Greg's summary of the web focus on glial cells in the current issue of Nature Neuroscience.