Archive for the ‘brain’ Category

Rat brains provide even more evidence our brains operates near tipping point

June 7th, 2019
A real human brain suspended in liquid within a human silhouette carved into acrylic, on display at the Bristol Science Centre in England. New research finds more evidence that the brain operates near a critical point.

Enlarge / A real human brain suspended in liquid within a human silhouette carved into acrylic, on display at the Bristol Science Centre in England. New research finds more evidence that the brain operates near a critical point. (credit: Ben Birchall/PA Images/Getty Images)

The human brain doesn't seem like it would have much in common with how water freezes into ice, or heats up into a gas. But over the last decade, evidence has been mounting that the brain as a system functions much like water approaching the critical point of a phase transition. Now a team of Brazilian scientists has found additional evidence in rat brains that this might indeed be the case. The team described its findings in a recent paper in Physical Review Letters.

The notion of so-called "self-organized criticality" dates back to a landmark paper in 1987, when the late Danish physicist Per Bak concluded that nature's exquisite order was the result of a kind of phase transition. That precise moment of transition is colloquially known as the "tipping point" or "critical point."

A brain's the thing

Typically, a classical phase transition only occurs when the temperature and pressure are just right for a given system. Self-organized criticality emerges spontaneously as the result of many local interactions between the many elements of a system, like millions of grains of sand running from the top to the bottom of an hourglass. The pile grows, grain by grain, until it becomes sufficiently unstable that the next grain to drop makes the pile collapse in an avalanche. The base of the pile widens, restoring stability, and the pile-up begins anew, until the sand pile hits the critical point again. Those avalanches follow a so-called "power law," meaning smaller ones happen more often than larger ones.

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Posted in brain, brain activity, criticality, neurophysics, Neuroscience, phase transitions, Physics, science, self-organized criticality | Comments (0)

Electrical jolts to brain restored memory of elderly to that of 20-year-old

April 9th, 2019
A patient wearing an electrical cap similar to the one used in the study.

Enlarge / A patient wearing an electrical cap similar to the one used in the study. (credit: Getty | BSIP)

Gentle jolts of alternating current to the brain restored the waning working memories of older adults (aged 60 to 76 years old) to performance levels seen in younger adults (aged 20 to 29)—at least for a little under an hour.

The scalp-delivered electrical bursts appeared to resync brain waves across areas of the noggin important for high-level thinking and memory—the prefrontal and temporal cortex—which appeared to have fallen out of step over the years. The results, published Monday in Nature Neuroscience, support the idea that out-of-sync ripples of electrical activity from neurons firing in different areas of the brain may help spark gradual declines in working memory during aging, as well as memory deterioration associated with dementias, such as Alzheimer’s. Moreover, the finding generates some early buzz that such non-invasive brain stimulation may one day, in the distant future, be used as a therapy for such memory issues.

The authors of the study, Boston University researchers Robert Reinhart and John Nguyen, concluded that “by customizing electrical stimulation to individual network dynamics it may be possible to influence putative signatures of intra- and inter-regional functional connectivity, and rapidly boost working-memory function in older adults.”

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Posted in Aging, Alzheimer's, brain, brain stimulation, memory, Neuroscience, science | Comments (0)

Stem cells used to trace autism back to the formation of neurons

January 8th, 2019
Microscopic closeup of human cells.

Human stem cells forming mature neurons. (credit: Dr. Ariadna Recasens, University of Sydney)

While autism is a spectrum of disorders, it's clear that the more significant cases involve physical differences in the brain's nerve cells. Several studies have reported an excess in connections among neurons in the brains of people with autism. But when does this happen? Changes in neural connections are key components of learning and memory, and they can happen at any point in life; major reorganizations in connectivity occur from before birth up to the late teens.

Anecdotal reports of autism's symptoms often suggest an onset between one and two years old. But a new study places the critical point extremely early in embryo development—at a point before there are any mature nerve cells whatsoever.

A series of challenges

Figuring out how autism starts is complicated. To begin with, it's a spectrum that might include more than one disorder. You also can't know in advance who's going to develop it, so you can only look at it retrospectively, after the problems are apparent. Finally, the human brain is simply not something you can ethically do invasive experiments on.

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Posted in autism, Biology, brain, developmental biology, Neuroscience, science | Comments (0)

Wireless Brain Interface Can Make the Paralyzed Walk Again

November 12th, 2016

By Uzair Amir

After successful results on monkeys, scientists claim paralyzed people can

This is a post from HackRead.com Read the original post: Wireless Brain Interface Can Make the Paralyzed Walk Again

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