Posts tagged brainwaves
Articles and news from the latest research reports.
Two minds are better than one
Scientists at the Essex have been working with NASA on a project where they controlled a virtual spacecraft by thought alone.
Using BCI (brain-computer interface) technology, they found that combining the brain power of two people could be more accurate in steering a spacecraft than one person. BCIs convert signals generated from the brain into control commands for various applications, including virtual reality and hands-free control.
Researchers at Essex have already been undertaking extensive projects into using BCI to help people with disabilities to enable spelling, mouse control or to control a wheelchair. The research involves the user carrying our certain mental tasks which the computer then translates into commands to move the wheelchair in different directions.
The University has built-up an international reputation for its BCI research and is expanding its work into the new area of collaborative BCI, where tasks are performed by combining the signals of multiple BCI users.
The £500,000 project with NASA’s Jet Propulsion Lab in Pasadena, California, involved two people together steering a virtual spacecraft to a planet using a unique BCI mouse, developed by scientists at Essex.
Using electroencephalography (EEG), the two users wore a cap with electrodes which picked up different patterns in the brainwaves depending on what they were focusing their attention on a screen – in this case one of the eight directional dots of the cursor. Brain signals representing the users’ chosen direction, as interpreted by the computer, were then merged in real time to produce control commands for steering the spacecraft.
As Professor Riccardo Poli, for the University’s School of Computer Science and Electronic Engineering, explained, the experiment was very intense and involved a lot of concentration. With two people taking part in the test, the results were more accurate as the system could cope if one of the users had a brief lapse in concentration.
Analysis of this collaborative approach showed that two minds could be better than one at producing accurate trajectories. Combining signals also helped reduce the random “noise” that hinders EEG signals, such as heartbeat, breathing, swallowing and muscle activity. “When you average signals from two people’s brains, the noise cancels out a bit,” added Professor Poli.
Professor Poli said an exciting development for BCI research in the future relates to joint decision making, where a physiological signal, like pressing a button, and brain activity can be combined to give a superior result. “It is like measuring someone’s gut feeling,” added Professor Poli.
(Source: essex.ac.uk)
Poor sleep in old age prevents the brain from storing memories
The connection between poor sleep, memory loss and brain deterioration as we grow older has been elusive. But for the first time, scientists at the University of California, Berkeley, have found a link between these hallmark maladies of old age. Their discovery opens the door to boosting the quality of sleep in elderly people to improve memory.
UC Berkeley neuroscientists have found that the slow brain waves generated during the deep, restorative sleep we typically experience in youth play a key role in transporting memories from the hippocampus – which provides short-term storage for memories – to the prefrontal cortex’s longer term “hard drive.”
However, in older adults, memories may be getting stuck in the hippocampus due to the poor quality of deep ‘slow wave’ sleep, and are then overwritten by new memories, the findings suggest.
“What we have discovered is a dysfunctional pathway that helps explain the relationship between brain deterioration, sleep disruption and memory loss as we get older – and with that, a potentially new treatment avenue,” said UC Berkeley sleep researcher Matthew Walker, an associate professor of psychology and neuroscience at UC Berkeley and senior author of the study published in the journal Nature Neuroscience.
Advanced brain investigations can become better and cheaper
A group of researchers at Chalmers University of Technology and the University of Gothenburg are now working on technology that can make MEG far more accessible. The vision is an MEG system that is simple and cheap enough to be available at every hospital, while furthermore providing totally new possibilities for fundamental investigations in brain research.
At the heart of the system is a new class of sensors that, unlike today’s MEG sensors, don’t require cooling to -269 Celsius. Instead, these work at -196 Celsius. This capability provides many advantages:
“One of them is the reduction of insulation between the sensors and the subject’s head,” says Dag Winkler, professor of physics at Chalmers. “The sensors can therefore get much closer to the brain so that one can take a more high-resolution picture of brain activity.”
With today’s technology, you can record activity from a patch of the brain that is roughly the size of a 1€ coin. With “Focal MEG” – MEG with liquid-nitrogen cooled sensors – the precision can be improved such that you’re recording from a patch of the brain that is a fraction of that size.
One example of what that can lead to is diagnosis of autism in children at a younger age – something that would be very meaningful considering how critical it is for these children to get the right help as early as possible.
“Another important advantage with Focal MEG is that the coolant the hardware requires is just liquid nitrogen”, Dag Winkler adds. “Today’s MEG requires liquid helium, which is extremely expensive. Furthermore, one can build the hardware with far more flexibility and less complication when using nitrogen instead of helium.”
The Gothenburg researchers have shown that Focal MEG works for advanced brain investigations. Using two sensors they developed, they have successfully recorded spontaneous brain activity –something that had never been done before with liquid-nitrogen cooled sensors. The ability to record spontaneous brain activity (as opposed to averaged activity from repetitive stimulation) is a solid indication that they can record more complicated brain activity.
“The prevailing assumption among MEG researchers has been that MEG with liquid-nitrogen cooled sensors isn’t feasible,” says Justin Schneiderman, assistant professor in biomedical engineering at the University of Gothenburg and MedTech West. “But now we’ve begun to expose holes in that assumption by demonstrating good sensitivity to two well-known brain waves from well-understood parts of the brain.”
The researchers have furthermore made an unexpected finding. They have recorded an uncharacteristically strong brain wave – the so-called theta rhythm – from the back of the brain. Today’s methods tend to find theta waves only in other parts of the brain.
“This is quite exciting,” says Mikael Elam, professor in clinical neurophysiology at the University of Gothenburg. “It may be an as-yet undetected type of brain signal that can only be found when one measures as close to the head as we do.”
(Source: chalmers.se)
Gustav Metzger Thinks About Nothing
In an attempt to create a visual representation of empty thoughts, artist Gustav Metzger hooked himself up to a robot carving machine, that turned his brainwaves into a sculpture.
This data was then fed to a manufacturing robot, which carved the Null Object sculpture out of a piece of Portland Stone.
The result is a brain-like object, dotted with crystalline, ovoid shapes. Metzger’s empty brain.
The project is being exhibited at London’s Work Gallery, and an accompanying book features further explorations of emptiness, including novelist Hari Kunzru on nothingness as a productive category, and Bronac Ferran on ‘the radical consequences of emptiness’.
Null Object: Gustav Metzger Thinks About Nothing, is at Work Gallery, 10a Acton Street, London WC1X, until 9 February 2013.
Surprising results from study of non-epileptic seizures
A Loyola University Medical Center neurologist is reporting surprising results of a study of patients who experience both epileptic and non-epileptic seizures.
Non-epileptic seizures resemble epileptic seizures, but are not accompanied by abnormal electrical discharges. Rather, these seizures are believed to be brought on by psychological stresses.
Dr. Diane Thomas reported that 15.7 percent of hospital patients who experienced non-epileptic seizures also had epileptic seizures during the same hospital stay. Previous studies found the percentage of such patients experiencing both types of seizures was less than 10 percent.
Thomas reported the findings Dec. 2 at a meeting of the American Epilepsy Society.
The finding is significant because epileptic and non-epileptic seizures are treated differently. Non-epileptic seizures do not respond to epilepsy medications, and typically are treated with psychotherapy, anti-depressants, or both, Thomas said.
Non-epileptic seizures used to be called pseudoseizures. But they are quite real, and the preferred term now is psychogenic non-epileptic seizure. A non-epileptic seizure can resemble the convulsions characteristic of a grand mal epileptic seizure, or the staring-into-space characteristic of a petit mal epileptic seizure. But unlike an epileptic seizure, the brain waves during a non-epileptic seizure are normal.
Non-epileptic seizures can be triggered by stresses such as physical or sexual abuse, incest, job loss, divorce or death of a loved one. In some cases, the traumatic event may be blocked from the patient’s conscious memory.
Non-epileptic seizures often are mistaken for epileptic seizures. While some patients who have both types can distinguish between the two, others find it difficult to distinguish when they are having non-epileptic seizures.
The only way to make a definitive seizure diagnosis is to monitor a patient with an electroencephalogram (EEG) and a video camera. (The EEG can detect abnormal electrical discharges that indicate an epileptic seizure.) The patient is monitored with the camera until a seizure occurs, and the EEG recordings from the event are then analyzed.
Thomas conducted her study at the University of Maryland Medical Center, where she did a fellowship in epilepsy before recently joining Loyola. Thomas and colleagues reviewed 256 patients who had come to the hospital to have their seizures monitored. Seventy of the patients had documented non-epileptic seizures. Of these, 11 patients (15.7 percent) also experienced epileptic seizures during their hospital stays.
(Source: eurekalert.org)
Duetting musicians sync brainwaves even when playing different notes
According to a study published by a team of psychologists, musicians playing different parts of a duet aren’t just syncing time — they synchronise brainwaves.
Johanna Sänger of Berlin’s Max Planck Institute for Human Development gathered 32 guitarists and arranged them in pairs to play Sonata in G Major by Christian Gottlieb Scheidler. Each musician was hooked up to electrodes, so Sänger and her team could monitor their brain activity the 60 times they were asked to play the composition. An earlier study from the Institute had already demonstrated that guitarists playing the exact same tune begin to share brainwave patterns. However, in this study Sänger asked the musicians to play different parts from the same piece of music. As well as playing totally different notes, one was asked to take the lead and set the tempo for the other to follow. Her hypothesis was that, if the brainwave patterns again aligned, then it would demonstrate they have an inherently important role in musicians’ “interpersonally coordinated behaviour” — or, their ability to play well as a pair. All pairs did in fact present with synchronised brain oscillations.
"When people coordinate their own actions, small networks between brain regions are formed," said Sänger. "But we also observed similar network properties between the brains of the individual players, especially when mutual coordination is very important; for example at the joint onset of a piece of music."
The synchronisation is known as “phase locking”, and took place largely where the frontal and central electrodes were placed (the frontal lobe is responsible for retaining long term memory, aligning emotion memory with social norms and predicting an action’s consequences).
The results prove, says the paper, that synchronisation of brain patterns plays “a functional role in music performance”, but also “that brain mechanisms indexed by phase locking, phase coherence, and structural properties of within-brain and hyperbrain networks support interpersonal action coordination”.
Sänger also found that the “leader’s” brainwaves were stronger and began before the music did, demonstrating their “decision to begin playing at a certain moment in time” as represented by well-coordinated frontal lobe activity.
Brain waves encode rules for behavior
One of the biggest puzzles in neuroscience is how our brains encode thoughts, such as perceptions and memories, at the cellular level. Some evidence suggests that ensembles of neurons represent each unique piece of information, but no one knows just what these ensembles look like, or how they form.
A new study from researchers at MIT and Boston University (BU) sheds light on how neural ensembles form thoughts and support the flexibility to change one’s mind. The research team, led by Earl Miller, the Picower Professor of Neuroscience at MIT, identified groups of neurons that encode specific behavioral rules by oscillating in synchrony with each other.
The results suggest that the nature of conscious thought may be rhythmic, according to the researchers, who published their findings in the Nov. 21 issue of Neuron.
“As we talk, thoughts float in and out of our heads. Those are all ensembles forming and then reconfiguring to something else. It’s been a mystery how the brain does this,” says Miller, who is also a member of MIT’s Picower Institute for Learning and Memory. “That’s the fundamental problem that we’re talking about — the very nature of thought itself.”
Ever wondered what your brain sounds like? Now you can hear the sweet melody of the mind by listening to sound composed from an analysis of brain activity.
Naturally, our brain activity waxes and wanes. When listening, this oscillation synchronizes to the sounds we are hearing. Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences have found that this influences the way we listen. Hearing abilities also oscillate and depend on the exact timing of one’s brain rhythms. This discovery that sound, brain, and behaviour are so intimately coupled will help us to learn more about listening abilities in hearing loss.