Paralysed people can now control computer cursor with thought Published: Monday, Nov 19, 2012, 17:26 IST Place: Washington, DC | Agency: ANI

In recent years, neuroscientists and neuroengineers working in prosthetics have begun to develop brain-implantable sensors that can measure signals from individual neurons, and after passing those signals through a mathematical decode algorithm, can use them to control computer cursors with thoughts. Now, a team of Stanford researchers including Indian origins have developed an algorithm, known as ReFIT, that vastly improves the speed and accuracy of neural prosthetics that control computer cursors. Research associate Dr Vikash Gilja and bioengineering doctoral candidate Paul Nuyujukian led the team. In side-by-side demonstrations with rhesus monkeys, cursors controlled by the ReFIT algorithm doubled the performance of existing systems and approached performance of the real arm. Better yet, more than four years after implantation, the new system is still going strong, while previous systems have seen a steady decline in performance over time. "These findings could lead to greatly improved prosthetic system performance and robustness in paralysed people, which we are actively pursuing as part of the FDA Phase-I BrainGate2 clinical trial here at Stanford," said Krishna Shenoy, a professor of electrical engineering, bioengineering and neurobiology at Stanford. The system relies on a silicon chip implanted into the brain, which records "action potentials" in neural activity from an array of electrode sensors and sends data to a computer. The frequency with which action potentials are generated provides the computer key information about the direction and speed of the user's intended movement The ReFIT algorithm that decodes these signals represents a departure from earlier models. The system is able to make adjustments on the fly when while guiding the cursor to a target, just as a hand and eye would work in tandem to move a mouse-cursor onto an icon on a computer desktop. If the cursor were straying too far to the left, for instance, the user likely adjusts their imagined movements to redirect the cursor to the right To test the new system, the team gave monkeys the task of mentally directing a cursor to a target "an onscreen dot" and holding the cursor there for half a second. ReFIT performed vastly better than previous technology in terms of both speed and accuracy. The path of the cursor from the starting point to the target was straighter and it reached the target twice as quickly as earlier systems, achieving 75 to 85 percent of the speed of real arms. "This paper reports very exciting innovations in closed-loop decoding for brain-machine interfaces. These innovations should lead to a significant boost in the control of neuroprosthetic devices and increase the clinical viability of this technology," said Jose Carmena, associate professor of electrical engineering and neuroscience at the University of California Berkeley. Critical to ReFIT's time-to-target improvement was its superior ability to stop the cursor. While the old model's cursor reached the target almost as fast as ReFIT, it often overshot the destination, requiring additional time and multiple passes to hold the target The team introduced a second innovation in the way ReFIT encodes information about the position and velocity of the cursor. Gilja said that previous algorithms could interpret neural signals about either the cursor's position or its velocity, but not both at once. ReFIT can do both, resulting in faster, cleaner movements of the curso The results have been published in the journal Nature Neuroscience.

 Oxytocin ('the Love Hormone') Makes Men in Relationships Want to Stay Away From Other Women

By Lindsay Abrams

inShare1 Nov 16 2012, 8:31 AM ET 19 And it apparently comes in a nasal spray.

eivindw/Flickr

PROBLEM: Oxytocin -- a hormone released by the pituitary gland (notably during both orgasm and childbirth) -- is known to affect our behavior. It promotes bonding, sometimes to the extent of making us conformists. Researchers in Germany suspected that a dose of the so-called "love hormone" during a flirtatious encounter with a sexy stranger might cause us to draw in closer, perhaps going so far as to spark a dangerous liaison.
METHODOLOGY: The research team singled out the most attractive female among them to approach their male subjects. Each of the 57 men had been administered either oxytocin or a placebo via nasal spray prior to the encounter. The attractive researcher would stand about 24 inches away from the subject, and then move toward and away from them. The men were asked to determine when the attractive researcher was at an "ideal distance" and when she got too close, making them feel "slightly uncomfortable."
The men confirmed after the experiment was completed that the attractive researcher was, in fact, attractive.
RESULTS: Unexpectedly, the men who had received oxytocin and who were also in monogamous relationships preferred keeping a significantly greater distance between themselves and the temptress researcher -- the hormone promoted bonding with their significant other, not the stranger. They stayed an average of 4 to 6 inches further back than oxytocin-induced singletons or anyone from the placebo group.

---

• Worrying About Math Can Activate Pain Areas in the Brain
• Exercise May Improve Sperm Quality
• When in Doubt, Go For a Handshake

---

This difference was not observed when the subjects were approached by a male researcher (of undetermined attractiveness), and occurred independently of the amount of eye contact made or whether it was the men or the attractive researcher doing the approaching.
Neither oxytocin nor relationship status affected the men's perception of how attractive the attractive researcher was.
CONCLUSION: Oxytocin promotes monogamy by preventing men from "signaling romantic interest" to other women.
IMPLICATION: If you can't get your hands on the nasal spray, there are plenty of ways in which oxytocin release can be stimulated during a monogamous relationship. Sex, yes, but also hand-holding and touch are known to trigger the hormone. However, the researchers warn, "it is clear that for these potential fidelity-enhancing effects to be revealed, female partners would need to evoke its endogenous release immediately before contexts in which the men might encounter other women."
The full study, "Oxytocin Modulates Social Distance between Males and Females" is published in the Journal of Neuroscience .

Time's up: Gene can predict what time of day you will die

• Daily Mail
• November 19, 2012 11:06AM

• Increase Text Size
• Decrease Text Size
• Print
• Email

Scientists have discovered a gene that predicts the time of day that you’ll die. 'Not the date, fortunately, but the time of day,' says one. File image Source: Supplied

Start of sidebar. Skip to end of sidebar.

Dumb Ways to Die video a smash

End of sidebar. Return to start of sidebar.

SCIENTISTS have discovered a gene variation that affects the human body clock so profoundly that it even predicts the time of day when an individual is most likely to die.

Researchers hope the findings could eventually be used to determine when heart or stroke patients should take medication to make it most effective, or when hospital patients should be monitored most closely.
The US team discovered the gene variation by accident when they were investigating the development of Parkinson’s and Alzheimer’s disease.
They looked at the sleeping patterns of 1200 healthy 65-year-olds who were also given annual neurological and psychiatric assessments.
They found a single molecule near a gene called ‘Period 1’ that had as its base either adenine (A) or guanine (G).
Type A is more common by a ratio of six to four, so because people have two sets of chromosomes, an individual has a 36 per cent chance of having two As, a 16 per cent chance of having two Gs, and a 48 per cent chance of an A and a G.

The findings, published in the Annals of Neurology, showed that those with a AA genotype tend naturally to wake up about an hour earlier than those with GG, and the AGs wake up almost exactly in the middle.
They also showed that those with the AA or AG genotype died just before 11am on average, but those with the GG genotype tended to die at just before 6pm.
The study’s lead author Andrew Lim, from the Department of Neurology at Beth Israel Deaconess Medical Center in Boston, Massachusetts, said: "The internal “biological clock” regulates many aspects of human biology and behaviour.
"It also influences the timing of acute medical events like stroke and heart attack."
Clifford Saper, chief of neurology at BIDMC, said: "So there is really a gene that predicts the time of day that you’ll die. Not the date, fortunately, but the time of day."