Archive for the ‘Neuroscience’ Category

This is your brain on bungee jumping: Cliff divers take the leap for science

March 1st, 2019
A man bungee jumps from a metal bridge toward the village below him.

Enlarge / A study participant has his brain waves recorded as he leaps from the Europa Bridge near Innsbruck, Austria, into a 630-foot abyss. Thank goodness for that bungee cord. (credit: Soekadar/Charite)

Right before you work up the nerve to leap off a bungee-jumping platform and plummet toward the Earth, there will be a sharp, measurable increase in your brain activity—almost a full second before you make the conscious decision to jump. A new paper in Scientific Reports purports to describe the first time this effect has been measured outside the laboratory.

That telltale signal was dubbed bereitschaftspotential (BP)—or "readiness potential" in English—when it was first observed in 1964 by Luder Deecke and Hans-Helmut Kornhuber. Kornhuber and Deecke had subjects make hundreds of voluntary finger movements while otherwise sitting as still as possible in a Faraday cage. The researchers noticed a shift in the electrical voltage in the brain, as measured by electroencephalography (EEG) electrodes placed along the scalp. The effect is often cited in the ongoing, heated debate over whether or not humans truly have free will.

The German and Austrian authors of the current study opted to have their subjects go bungee jumping in hopes of recording this readiness potential. While bungee jumping has its roots in an ancient ritual on the South Pacific island-nation of Vanuatu as a way to test one's courage, prior studies have shown it results in a sharp rise in concentrations of beta-endorphins right after jumping. (This spike is despite the fact that, the authors note, bungee jumping is statistically less life-threatening than more common activities like bicycling or dancing. Our impulse reactions are not rational.)

Read 6 remaining paragraphs | Comments

Posted in brain-computer interface, bungee jumping, Neuroscience, psychiatry, readiness potential, science | Comments (0)

Singing mice could offer clues about how human brains manage conversation

February 28th, 2019
This singing mouse species (<em>Scotinomys teguina</em>) thrives in the cloud forests of Costa Rica. Their songs could yield clues about how human brains accomplish the "turn-talking" that makes conversation possible.

Enlarge / This singing mouse species (Scotinomys teguina) thrives in the cloud forests of Costa Rica. Their songs could yield clues about how human brains accomplish the "turn-talking" that makes conversation possible. (credit: NYU School of Medicine)

High in the cloud forests of Costa Rica, there's a species of mouse that sings call-and-response duets, similar to the high-speed back and forth humans engage in with conversation. Now scientists have pinpointed the precise brain circuit responsible for this behavior, which may lead to fresh insights into how humans converse, according to a new paper in Science.

Co-author Michael Long of New York University's School of Medicine calls this conversational back and forth "turn talking," likening it to hitting a tennis ball back and forth over a net between two players. "If I were to summarize [the results] in one sentence, I'd say this is the first demonstration of the neural mechanisms that lead to coordinated vocal turn-talking in the mammalian brain," he said. "Our strong prediction from the mouse study is that a similar kind of vocal coordination center may exist in the human brain as well."

Long's lab specializes in the study of vocal communication, something at which human beings excel. We don't often stop to think about the intricate neural processing even a simple conversation requires. The pause time between when one speaker finishes and another begins—called "floor transfer time"—is just 200 milliseconds. But one in ten people experiences some form of communication disorder, whether due to a stroke or a developmental disorder like autism.

Read 14 remaining paragraphs | Comments

Posted in Biology, Neuroscience, science, singing mice | Comments (0)

Watching brains on acid using an MRI

February 1st, 2019
LSD blotter paper

Enlarge / LSD blotter paper (credit: campusdrugprevention.gov)

What exactly happens in a brain when it is hit by a hallucinogen? Lots of drugs have effects that are obvious extensions of our normal body processes; they raise moods, dull pain, or boost our energy. But hallucinogens are notable for giving their users experiences that are anything but normal.

Now, a team of Swiss researchers have used MRI imaging to follow the brain as it's under the influence of acid. And their results support the idea that hallucinogens cause the breakdown of the system that helps the brain keep track of which information is coming from the real world and which is generated by the brain itself.

Cortex overload

The brain receives a steady flow of information, some from the outside world, some from the body, and some generated by its internal thought processes. Your brain has to essentially decide which of it to take seriously and raise to the level of consciousness, which to monitor subconsciously, and which to discard. Hallucinations, whether due to drugs or mental disorders, appear to involve a breakdown in this information processing.

Read 12 remaining paragraphs | Comments

Posted in Biology, drugs, fMRI, hallucinogens, 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.

Read 11 remaining paragraphs | Comments

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

Autism involves a large-scale reduction in RNA editing

December 21st, 2018
Multicolored image of the neural connections within a brain.

Enlarge (credit: Erin Hecht, Dietrich Stout)

Most genes encode proteins and are transcribed from DNA into RNA before they're translated into a protein. In complex cells, however, there are lots of added layers of complexity. The RNA typically has chunks cut out of it, has its start and end modified, and more. Collectively, these changes are called RNA processing.

Xinshu Xiao's lab at UCLA studies RNA processing in all of its many forms. RNA editing is a type of modification that involves the alteration of RNA sequences by swapping in different bases. This has the effect of increasing the number of different protein products that can be generated from a single gene.

RNA editing is known to be important in nervous system development, specifically the formation of connections between nerve cells, called synapses. Synaptic development is abnormal in autism spectrum disorders. So Xiao and her colleagues decided to look at RNA editing in the brains of people with autism. They found that RNA editing was reduced in multiple areas of the brain, and multiple genes were affected.

Read 8 remaining paragraphs | Comments

Posted in autism, autism spectrum disorder, Neuroscience, RNA, science | Comments (0)

Spinal-cord stimulation allows three paralyzed men to walk, with assistance

October 31st, 2018
Multiple combined images of a man starting out in a wheelchair progressing to using a wheeled walker.

Enlarge / A composite image showing David Mzee standing and walking with assistance. (credit: EPFL / Hillary Sanctuary)

“It’s an amazing feeling,” says David Mzee, whose left leg was paralyzed in 2010. Mzee has now regained some ability to walk, thanks to a breakthrough in spinal-cord stimulation technology. “I can do a knee extension of my left leg... flex my hip and even move my toes.”

Mzee is one of three participants in a study that used a new technique to overcome spinal-cord injury and restore walking ability in patients with varying degrees of paralysis. The results, published in Nature and Nature Neuroscience today, are dramatic. All three patients recovered some degree of walking ability, and their progress in physical-therapy sessions has translated to improved mobility in their daily lives.

The basis of the technique, called epidural electrical stimulation (EES), is not new at all—it’s been investigated as a potential treatment for paralysis for decades, with a lot of success in animals. And in September this year, two separate papers reported breakthroughs in allowing patients with paralysis to walk, with assistance, as a result of EES.

Read 14 remaining paragraphs | Comments

Posted in Health, medicine, Neuroscience, science | Comments (0)

What watching Forrest Gump tells us about how we store memories

October 18th, 2018
Participants in new neuroimaging study watched an edited version of <em>Forrest Gump</em>.

Enlarge / Participants in new neuroimaging study watched an edited version of Forrest Gump. (credit: Paramount Pictures)

Watching the 1995 film Forrest Gump can elicit sincere emotion and pleasure or more negative responses in viewers, depending on one's subjective cinematic tastes. It can also teach neuroscientists something about how the brain encodes everyday events into long-term memory, according to a recent study published in the Journal of Neuroscience. The brain seems most interested in tracking transitions between distinct events, the better to segment and store them.

The hippocampus is the brain region most closely associated with forming new memories. Most experiments focusing on memory use the most minimal, simplified stimuli possible to better control for variables, according to co-author Aya Ben-Yakov of the University of Cambridge. But in reality, the brain actually processes a huge amount of continually incoming stimuli. This is the first study to specifically investigate how the hippocampus operates during so-called "natural experiences."

Films turn out to be ideal for simulating that kind of natural continuous input, mimicking our daily lived experience. And Forrest Gump is one of the most popular with neuroscientists, thanks in large part to an open source dataset called studyforrest. Founded in 2013, the project is a repository for experiments that study the brain's natural behavior in response to watching the film, using fMRI, eye tracking, structural brain scans, and more.

Read 12 remaining paragraphs | Comments

Posted in Forrest Gump, hippocampus, memory, Neuroscience, science | Comments (0)

Hearing voices? You might just be primed for it

August 27th, 2017

Enlarge (credit: flickr user: David Wood)

Hallucinations tend to be associated with psychosis, but the reality is more complicated than that. Some people who hear voices don’t suffer from other mental health problems, and the voices they hear aren’t distressing. These “non-clinical voice-hearers” provide an important opportunity to understand hallucinations without the complications of mental illness or medication.

A preliminary study published this week in the journal Brain reports that non-clinical voice-hearers were more likely to detect language in a recording of distorted speech. Voice-hearers also showed some different patterns in brain activation as they listened. The results could help to explain why some people are more likely to hear voices, as well as help to direct future research on the topic.

Hearing meaning in noise

Ben Alderson-Day, the lead author on the paper, is a psychologist at Durham University whose research focuses on auditory hallucinations. To investigate differences of perception in voice-hearers, Alderson-Day and his colleagues used sine-wave speech, which strips out some of the most vital acoustic properties of speech and leaves something that sounds kind of like a series of clicks and whistles. It’s possible to understand it—once you already know what it says, or once you’ve listened to quite a bit of sine-wave speech. (Listen to some examples here.)

Read 8 remaining paragraphs | Comments

Posted in Behavioral science, Biology, Neuroscience, science | Comments (0)

Booze boosts the brain’s ability to remember info learned before drinking

August 3rd, 2017

Enlarge (credit: Getty | FRANCOIS GUILLOT )

Cheers!—not to your health, but to your memory.

Drinking alcohol after learning information appears to aid the brain’s ability to store and remember that information later, according to a study of at-home boozing in Scientific Reports. The memory-boosting effect—which has been seen in earlier lab-based studies—linked up with how much a person drank: the more alcohol, the better the memory the next day.

The study authors, led by psychopharmacologist Celia Morgan of University of Exeter, aren’t sure why alcohol improves memory in this way, though. They went into the experiment hypothesizing that alcohol blocks the brain’s ability to lay down new memories, thus freeing up noggin power to carefully encode and store the fresh batch of memories that just came in. In other words, after you start drinking, your ability to remember new things gets wobbly, but your memory of events and information leading up to that drink might be sturdier than normal.

Read 12 remaining paragraphs | Comments

Posted in alcohol, drinking, memory, Neuroscience, science | Comments (0)

This Organic Computer is Made up from Brains of Rats and Monkeys

July 10th, 2015

Brains are more powerful than computers. So why not build a computer from Brain? 

In fact, Multiple Brains as per sayings, “Two heads are better than one.”

Scientists at Duke University have done exactly that. They have successfully developed the first instance of a Brain-machine interface that employs multiple brains at once to operate a single machine.

“Organic Computers” – Made

Posted in brain hacking, hacking news, Information Security, neurobiologist, neurobiology, Neuroscience, Neuroscientist, organic computer, Technology News | Comments (0)