brain

Lightweight, open, mobile, cheaper MRI brain scanner prototype working in lab

Attila Csordas — Wed, 17 Sep 2008 15:13:20 -0700

Description

Those giant, claustrophobic, tunnel forming magnets used for magnetic resonance imaging (MRI) in labs and hospitals look so last century! They are pricey and heavy, making MRI systems immobile and demanding to install. Any alternative? Yes by implementing the pre-polarized MRI concept introduced some 15 years ago:

"Writing in the Journal of Magnetic Resonance, Vadim Zotev and colleagues report success in imaging a human brain using a different type of MRI system: lightweight, open, mobile and significantly cheaper.

By dividing the functions of these large-field magnets between two sets of magnets with different characteristics, Zotev et al. have produced the prototype of a machine that would be smaller and more open, as well as being capable of performing magnetic resonance imaging and magnetoencephalography at the same time.

Conventional MRI machines reconcile these different requirements by using magnets that are both powerful and homogeneous. But could the same effect be achieved by using two simpler magnets and switching between them? The first magnet, strong but relatively inhomogeneous, would polarize the sample, whereas the second, weak but highly homogeneous, would be optimized for collecting resonance signals. This concept, termed pre-polarized MRI, was originally introduced by Macovski and Conolly2 some 15 years ago, and has been pursued by several research teams since.

Zotev et al. now report obtaining images of a living human brain using pre-polarization at 30 millitesla (mT) and image data collection at just 46 microT, a similar strength to that of Earth's magnetic field and about 30,000 times weaker than that of typical clinical MRI machines. Using such small magnetic fields means that the frequencies of the signals produced by the oscillating nuclear spins are similarly reduced from the usual radiofrequency range to around 2 kilohertz — a frequency readily audible to the human ear (approximately three octaves above middle C)."

Biomedical Sciences and Biotechnology

Source

Klaas P. Pruessmann: Medical imaging: Less is more
Nature 455, 43-44 (4 September 2008) | doi:10.1038/455043a
http://www.nature.com/nature/journal/v455/n7209/full/455043a.html

Zotev et al.: Microtesla MRI of the human brain combined with MEG.
J Magn Reson. 2008 Sep;194(1):115-20.
http://www.ncbi.nlm.nih.gov/pubmed/18619876?dopt=Abstract&holding=npg

The Moral Instinct - New York Times

Max Marmer — Wed, 11 Jun 2008 14:08:58 -0700

Description

Great article by Steven Pinker providing a framework to understanding how morals work and how they might have evolved.

Today, a new field is using illusions to unmask a sixth sense, the moral sense. Moral intuitions are being drawn out of people in the lab, on Web sites and in brain scanners, and are being explained with tools from game theory, neuroscience and evolutionary biology.

Here's an excerpt from the article where Steven Pinker illuminates contradictions in how we think about morals.
It’s not just the content of our moral judgments that is often questionable, but the way we arrive at them. We like to think that when we have a conviction, there are good reasons that drove us to adopt it. That is why an older approach to moral psychology, led by Jean Piaget and Lawrence Kohlberg, tried to document the lines of reasoning that guided people to moral conclusions. But consider these situations, originally devised by the psychologist Jonathan Haidt:

Julie is traveling in France on summer vacation from college with her brother Mark. One night they decide that it would be interesting and fun if they tried making love. Julie was already taking birth-control pills, but Mark uses a condom, too, just to be safe. They both enjoy the sex but decide not to do it again. They keep the night as a special secret, which makes them feel closer to each other. What do you think about that — was it O.K. for them to make love?

A woman is cleaning out her closet and she finds her old American flag. She doesn’t want the flag anymore, so she cuts it up into pieces and uses the rags to clean her bathroom.

A family’s dog is killed by a car in front of their house. They heard that dog meat was delicious, so they cut up the dog’s body and cook it and eat it for dinner.

Most people immediately declare that these acts are wrong and then grope to justify why they are wrong. It’s not so easy. In the case of Julie and Mark, people raise the possibility of children with birth defects, but they are reminded that the couple were diligent about contraception. They suggest that the siblings will be emotionally hurt, but the story makes it clear that they weren’t. They submit that the act would offend the community, but then recall that it was kept a secret. Eventually many people admit, “I don’t know, I can’t explain it, I just know it’s wrong.” People don’t generally engage in moral reasoning, Haidt argues, but moral rationalization: they begin with the conclusion, coughed up by an unconscious emotion, and then work backward to a plausible justification.

Pinker goes on to describe many other blatant fallacies in what is considered morals - like why someone finds it morally acceptable to push a button that would kill one person but save five but would not push a person in front of a train to save five people, again sacrificing one for many...

Another very interesting aspect of the article talks about five common Universal Morals found around the globe that seem to form the blueprint for morality.
"The exact number of themes depends on whether you’re a lumper or a splitter, but Haidt counts five — harm, fairness, community (or group loyalty), authority and purity — and suggests that they are the primary colors of our moral sense. Not only do they keep reappearing in cross-cultural surveys, but each one tugs on the moral intuitions of people in our own culture."

Future of neuroscience

Source

http://www.nytimes.com/2008/01/13/magazine/13Psychology-t.html

Further scientific evidence that happiness has tangible health benefits.

Max Marmer — Tue, 10 Jun 2008 11:30:52 -0700

Description

BEP producing neurons, ‘feel good’ neurons that are activated during exercise or good conversation are found to have correlation with fighting cancerous tumors.

Scientists have been aware for many years that if cancer patients are not able to deal with the stress associated with being sick, the cancer will progress faster than in calmer patients. To counteract this phenomenon, physicians encourage treatments that help cancer patients handle their stress. Scientists theorized that the stress relief may have come as a result of increased beta-endorphin peptide (BEP)

Future of neuroscience

Source

http://physorg.com/news132251439.html

"Walking" in Second Life

Alex Soojung-Kim Pang — Mon, 02 Jun 2008 12:08:29 -0700

Description

A Japanese team of researchers, led by Keio University biosciences and informatics professor Junichi Ushiba, has created a system that allows a paralyzed man to "walk" in Second Life.

Wired reports,

Researchers at Japan's Keio University have created an experimental headset designed to monitor brain waves that allowed a man who had been paralyzed for more than 30 years to control a Second Life avatar using only his thoughts.

Despite his condition, a progressive muscle disease that prevents him from using a keyboard or mouse, the new technology allowed him to control a character using the same set of brain impulses normally used to move a person's arms and legs.

APF adds,

In the experiment, he wore headgear with three electrodes monitoring brain waves related to his hands and legs. Even though he cannot move his legs, he imagined that his character was walking.

He was then able to have a conversation with the other character using an attached microphone, said the researchers at Japan's Keio University....

Researchers are now studying a system that would let patients create text messages by mentally selecting certain letters, said Junichi Ushiba, associate professor at the biosciences and informatics department of Keio Universty's Faculty of Science and Technology....

This might at first sound like only a stunt, or a build on the work of people like Miguel Nicolesis, but Ushiba argues that "Second Life could motivate patients with severe paralysis, who are often too depressed to undergo rehabilitation."

Biomedical Sciences and Biotechnology

Source

http://blog.wired.com/games/2008/06/paralyzed-man-w.html
http://www.afp.com/english/news/stories/newsmlmmd.71e67dc51f1c1f69fc225747a71073eb.4b1.html

'Lab on a chip' mimics brain chemistry

Alex Soojung-Kim Pang — Mon, 11 Feb 2008 21:00:00 -0800

NOTE: This content was aggregated from RSS feed. Original source is http://www.eurekalert.org/pub_releases/2008-02/jhmi-oa021208.php

EurekAlert reports on a new lab on a chip system to study brain chemistry:

Johns Hopkins researchers from the Whiting School of Engineering and the School of Medicine have devised a micro-scale tool -- a lab on a chip -- designed to mimic the chemical complexities of the brain. The system should help scientists better understand how nerve cells in the brain work together to form the nervous system.

”The chip we’ve developed will make experiments on nerve cells more simple to conduct and to control,” says Andre Levchenko, Ph.D., associate professor of biomedical engineering at the Johns Hopkins Whiting School of Engineering and faculty affiliate of the Institute for NanoBioTechnology.

Nerve cells decide which direction to grow by sensing both the chemical cues flowing through their environment as well as those attached to the surfaces that surround them. The chip, which is made of a plastic-like substance and covered with a glass lid, features a system of channels and wells that allow researchers to control the flow of specific chemical cocktails around single nerve cells....

“The ability to combine several different stimuli in the chip resembles a more realistic environment that nerve cells will encounter in the living animal,” [Institute for Cell Engineering professor Guo-li] Ming says. This in turn will make future studies on the role of neuronal cells in development and regeneration more accurate and complete.