Posts tagged EEG
Articles and news from the latest research reports.
Brain and eye combined monitoring breakthrough could lead to fewer road accidents
Latest advances in capturing data on brain activity and eye movement are being combined to open up a host of ‘mindreading’ possibilities for the future. These include the potential development of a system that can detect when drivers are in danger of falling asleep at the wheel.
The research has been undertaken at the University of Leicester with funding from the Engineering and Physical Sciences Research Council (EPSRC), and in collaboration with the University of Buenos Aires in Argentina.
The breakthrough involves bringing two recent developments in the world of technology together: high-speed eye tracking that records eye movements in unprecedented detail using cutting-edge infra-red cameras*; and high-density electroencephalograph** (EEG) technology that measures electrical brain activity with millisecond precision through electrodes placed on the scalp.
The research has overcome previous technological challenges which made it difficult to monitor eye movement and brain activity simultaneously. The team has done this by developing novel signal processing techniques.
This could be the first step towards a system that combines brain and eye monitoring to automatically alert drivers who are showing signs of drowsiness. The system would be built into the vehicle and connected unobtrusively to the driver, with the EEG looking out for brain signals that only occur in the early stages of sleepiness. The eye tracker would reinforce this by looking for erratic gaze patterns symptomatic of someone starting to feel drowsy and different from those characteristic of someone driving who is constantly looking out for hazards. Fatigue has been estimated to account for around 20 per cent of traffic accidents on the UK’s motorways.***
The breakthrough achieved by the University of Leicester could also ultimately be built on to deliver many other everyday applications in the years ahead. For example:
- Computer games of the future could dispense with the need for the player to physically interact with any type of console, mouse or other hand-operated system. Instead, eye movement and brain activity data would be collected and processed to indicate what action the player wants to take. By distinguishing the tiny differences in various types of brain activity, the EEG would identify the precise action the player desires (e.g. run, jump or throw), while the eye movement data would show exactly where on the screen the player was looking when they had this thought. This information could be combined to enable the correct action to occur. An unobtrusive headset would be all that would be required to capture the necessary data.
- People who have no arm functionality could move their wheelchairs simply through their eye movements. These movements could be tracked and the corresponding brain activity analysed to identify when these indicate a desire to move in a certain direction. This would then automatically activate a steering and propulsion mechanism that would drive the wheelchair to that place.
- The breakthrough could also provide the basis for improved tests to diagnose dyslexia and other reading disorders. Current tests revolve around a rapid succession of single words flashed onto a computer screen, with the resulting brain activity monitored by EEG. The new technique could enable the person being tested to move their eyes and read longer passages of text in a natural way, making the tests much more realistic and revealing.
- With the basic concept now demonstrated successfully, the team aim to continue their work and eventually develop software that, in real time, automatically monitors both eye movement and brain activity.
- Dr Matias Ison, who has led the research, says: “Historically, eye-tracking and EEG have evolved as independent fields. We have managed to overcome the challenges that were standing in the way of integrating these technologies. This is already leading to a much better understanding of how the brain responds when the eyes are moving. Monitoring the alertness of drivers is just one of many potential applications for this work. Building on the foundation provided by our EPSRC-funded project, we hope to see the first of these starting to become feasible within the next three to five years.”
(Source: epsrc.ac.uk)
Helicopter takes to the skies with the power of thought
A remote controlled helicopter has been flown through a series of hoops around a college gymnasium in Minnesota.
It sounds like your everyday student project; however, there is one caveat…the helicopter was controlled using just the power of thought.
The experiments have been performed by researchers hoping to develop future robots that can help restore the autonomy of paralysed victims or those suffering from neurodegenerative disorders.
Their study has been published today, 4 June 2013, in IOP Publishing’s Journal of Neural Engineering and is accompanied by a video of the helicopter control in action.
There were five subjects (three female, two male) who took part in the study and each one was able to successfully control the four-blade helicopter, also known as a quadcopter, quickly and accurately for a sustained amount of time.
Lead author of the study Professor Bin He, from the University of Minnesota College of Science and Engineering, said: “Our study shows that for the first time, humans are able to control the flight of flying robots using just their thoughts, sensed from noninvasive brain waves.”
The noninvasive technique used was electroencephalography (EEG), which recorded the electrical activity of the subjects’ brain through a cap fitted with 64 electrodes.
Facing away from the quadcopter, the subjects were asked to imagine using their right hand, left hand, and both hands together; this would instruct the quadcopter to turn right, left, lift, and then fall, respectively. The quadcopter was driven with a pre-set forward moving velocity and controlled through the sky with the subject’s thoughts.
The subjects were positioned in front of a screen which relayed images of the quadcopter’s flight through an on-board camera, allowing them to see which direction it was travelling in. Brain signals were recorded by the cap and sent to the quadcopter over WiFi.
“In previous work we showed that humans could control a virtual helicopter using just their thoughts. I initially intended to use a small helicopter for this real-life study; however, the quadcopter is more stable, smooth and has fewer safety concerns,” continued Professor He.
After several different training sessions, the subjects were required to fly the quadcopter through two foam rings suspended from the gymnasium ceiling and were scored on three aspects: the number of times they sent the quadcopter through the rings; the number of times the quadcopter collided with the rings; and the number of times they went outside the experiment boundary.
A number of statistical tests were used to calculate how each subject performed.
A group of subjects also directed the quadcopter with a keyboard in a control experiment, allowing for a comparison between a standardised method and brain control.
This process is just one example of a brain–computer interface where a direct pathway between the brain and an external device is created to help assist, augment or repair human cognitive or sensory-motor functions; researchers are currently looking at ways to restore hearing, sight and movement using this approach.
“Our next goal is to control robotic arms using noninvasive brain wave signals, with the eventual goal of developing brain–computer interfaces that aid patients with disabilities or neurodegenerative disorders,” continued Professor He.
Scientists develop worm EEG to test the effects of drugs
Scientists from the University of Southampton have developed a device which records the brain activity of worms to help test the effects of drugs.
NeuroChip is a microfluidic electrophysiological device, which can trap the microscopic worm Caenorhadbitis elegans and record the activity of discrete neural circuits in its ‘brain’ - a worm equivalent of the EEG.
C. elegans have been enormously important in providing insight into fundamental signalling processes in the nervous system and this device opens the way for a new analysis. Prior to this development, electrophysiological recordings that resolve the activity of excitatory and inhibitory nerve cells in the nervous system of the worm required a high level of technical expertise - single microscopic (1mm long) worms have to be trapped on the end of a glass tube, a microelectrode, in order to make the recording. The worms are very mobile as well as being small and this can be a challenging procedure.
The microfluidic invention consists of a reservoir through which worms can be fed, one after the other, into a narrow fluid-filled channel. The channel tapers at one end and this captures the worm by the front end. The worm is then in the correct orientation for recording the activity of the nervous system in the anterior of its body. The device incorporates metal electrodes, which are connected to an amplifier to make the recording. The design of the trapping channel has been optimised by PhD student Chunxiao Hu, so that the quality of the worm ‘EEG’ recording is sufficient to resolve the activity of components of the neural circuit in the worm’s nervous system.
This device has been used to detect the effects of drugs and is highly suitable for high throughput screens (which allow researchers to quickly conduct millions of chemical, genetic or pharmacological tests) in neurotoxicology and for generic screening for neuroactive drugs. It has more power to resolve discrete effects on excitatory, inhibitory or modulatory transmission than previously possible with behavioural screens.
Lindy Holden-Dye, Professor of Neuroscience at the University of Southampton and lead author of the paper, says: “We are particularly interested in using this as a sensitive new tool for screening compounds for neurotoxicity. It will allow us to precisely quantify sub-lethal effects on neural network activity. It can also provide an information rich platform by reporting the effects of compounds on a diverse array of neurotransmitter pathways, which are implicated in mammalian toxicology. “
The research, which is published in the latest issue of the journal PLOS One, is a joint project between the University’s Centre for Biological Sciences and the Hybrid Biodevices Group.
The brain has been traditionally viewed as a deterministic machine where certain inputs give rise to certain outputs. However, there is a growing body of work that suggests this is not the case. The high importance of initial inputs suggests that the brain may be working in the realms of chaos, with small changes in initial inputs leading to the production of strange attractors. This may also be reflected in the physical structure of the brain which may also be fractal. EEG data is a good place to look for the underlying patterns of chaos in the brain since it samples many millions of neurons simultaneously. Several studies have arrived at a fractal dimension of between 5 and 8 for human EEG data. This suggests that the brain operates in a higher dimension than the 4 of traditional space-time. These extra dimensions suggest that quantum gravity may play a role in generating consciousness.
(Image courtesy: Kookmin University)
Babies develop conscious perception from five months of age
Infants develop the ability to consciously process their environment as early as five months of age, according to a study published in the journal Science.
The team of French and Danish researchers, led by neuroscientist Sid Kouider, discovered a signal in the nervous system of infants that reliably identifies the beginning of visual consciousness, or the ability to see something and recall that you have seen it.
The team set out believing infants had the capacity for conscious reflection, but they had to overcome the barrier that babies could not report their thoughts.
They used electroencephalography (EEG) to record electrical activity in the brains of 80 infants aged five, 12 and 15 months while they were shown pictures of faces and random patterns for a fraction of a second.
When adults are aware of a stimulus, their brains show a two-stage pattern of activity. When they see a moving object, the sensors in the vision centre of the brain activate with a spike of activity.
The signal then moves from the back of the brain to the prefrontal cortex, which deals with higher-level cognition. This is known as the late slow wave.
Conscious awareness begins after the second stage of neural activity reaches a specific threshold.
The new study found this two-stage pattern of brain activity was present in the three groups of infants, though it was weaker and more drawn out in the five-month-olds.
The researchers say neurological markers of visual consciousness may help paediatricians better manage infant pain and anaesthesia.
But they note the research does not provide direct proof of consciousness. “Indeed, it is a genuine philosophical problem whether such a proof can ever be obtained from purely neurophsysiological data,” the paper said.
Professor Louise Newman, Director of the Centre for Developmental Psychiatry & Psychology at Monash University, said the study was novel in its ability to measure the way very young brains register stimuli.
But five months should not be seen as a fixed point at which infants start to process information, she said.
“Although this group has studied five months and up, my suspicion would be that if we had different techniques, young infants – from birth on – would show the capacity of registering these sorts of stimuli.
“Infants are born with quite sophisticated capacities to observe, respond to and interact with the environment, particularly the social environment,” she said.
“Very soon after birth, infants will maintain gaze with their parents or parent: they’ve got quite sophisticated visual tracking capacity from an early age.”
Professor Newman, who has undertaken behavioural studies in two- to four-month olds, said young infant brains were extremely sensitive to their mother’s emotional reaction.
“They learn that ‘if I do this, or if I smile or signal in this way, this is what usually happens’. If you manipulate that so they don’t get that response, they’re very sensitive to that and they show signs that it’s very aversive to them.”
A team of researchers led by Associate Professor Maria Kozhevnikov from the Department of Psychology at the National University of Singapore (NUS) Faculty of Arts and Social Sciences showed, for the first time, that it is possible for core body temperature to be controlled by the brain. The scientists found that core body temperature increases can be achieved using certain meditation techniques (g-tummo) which could help in boosting immunity to fight infectious diseases or immunodeficiency.
Published in science journal PLOS ONE in March 2013, the study documented reliable core body temperature increases for the first time in Tibetan nuns practising g-tummo meditation. Previous studies on g-tummo meditators showed only increases in peripheral body temperature in the fingers and toes. The g-tummo meditative practice controls “inner energy” and is considered by Tibetan practitioners as one of the most sacred spiritual practices in the region. Monasteries maintaining g-tummo traditions are very rare and are mostly located in the remote areas of eastern Tibet.
The researchers collected data during the unique ceremony in Tibet, where nuns were able to raise their core body temperature and dry up wet sheets wrapped around their bodies in the cold Himalayan weather (-25 degree Celsius) while meditating. Using electroencephalography (EEG) recordings and temperature measures, the team observed increases in core body temperature up to 38.3 degree Celsius. A second study was conducted with Western participants who used a breathing technique of the g-tummo meditative practice and they were also able to increase their core body temperature, within limits.
Applications of the research findings
The findings from the study showed that specific aspects of the meditation techniques can be used by non-meditators to regulate their body temperature through breathing and mental imagery. The techniques could potentially allow practitioners to adapt to and function in cold environments, improve resistance to infections, boost cognitive performance by speeding up response time and reduce performance problems associated with decreased body temperature.
The two aspects of g-tummo meditation that lead to temperature increases are “vase breath” and concentrative visualisation. “Vase breath” is a specific breathing technique which causes thermogenesis, which is a process of heat production. The other technique, concentrative visualisation, involves focusing on a mental imagery of flames along the spinal cord in order to prevent heat losses. Both techniques work in conjunction leading to elevated temperatures up to the moderate fever zone.
Assoc Prof Kozhevnikov explained, “Practicing vase breathing alone is a safe technique to regulate core body temperature in a normal range. The participants whom I taught this technique to were able to elevate their body temperature, within limits, and reported feeling more energised and focused. With further research, non-Tibetan meditators could use vase breathing to improve their health and regulate cognitive performance.”
Further research into controlling body temperature
Assoc Prof Kozhevnikov will continue to explore the effects of guided imagery on neurocognitive and physiological aspects. She is currently training a group of people to regulate their body temperature using vase breathing, which has potential applications in the field of medicine. Furthermore, the use of guided mental imagery in conjunction with vase breathing may lead to higher body temperature increases and better health.
Easing Brain Fatigue With a Walk in the Park
Scientists have known for some time that the human brain’s ability to stay calm and focused is limited and can be overwhelmed by the constant noise and hectic, jangling demands of city living, sometimes resulting in a condition informally known as brain fatigue.
With brain fatigue, you are easily distracted, forgetful and mentally flighty — or, in other words, me.
But an innovative new study from Scotland suggests that you can ease brain fatigue simply by strolling through a leafy park.
The idea that visiting green spaces like parks or tree-filled plazas lessens stress and improves concentration is not new. Researchers have long theorized that green spaces are calming, requiring less of our so-called directed mental attention than busy, urban streets do. Instead, natural settings invoke “soft fascination,” a beguiling term for quiet contemplation, during which directed attention is barely called upon and the brain can reset those overstretched resources and reduce mental fatigue.
But this theory, while agreeable, has been difficult to put to the test. Previous studies have found that people who live near trees and parks have lower levels of cortisol, a stress hormone, in their saliva than those who live primarily amid concrete, and that children with attention deficits tend to concentrate and perform better on cognitive tests after walking through parks or arboretums. More directly, scientists have brought volunteers into a lab, attached electrodes to their heads and shown them photographs of natural or urban scenes, and found that the brain wave readouts show that the volunteers are more calm and meditative when they view the natural scenes.
But it had not been possible to study the brains of people while they were actually outside, moving through the city and the parks. Or it wasn’t, until the recent development of a lightweight, portable version of the electroencephalogram, a technology that studies brain wave patterns.
For the new study, published this month in The British Journal of Sports Medicine, researchers at Heriot-Watt University in Edinburgh and the University of Edinburgh attached these new, portable EEGs to the scalps of 12 healthy young adults. The electrodes, hidden unobtrusively beneath an ordinary looking fabric cap, sent brain wave readings wirelessly to a laptop carried in a backpack by each volunteer.
The researchers, who had been studying the cognitive impacts of green spaces for some time, then sent each volunteer out on a short walk of about a mile and half that wound through three different sections of Edinburgh.
The first half mile or so took walkers through an older, historic shopping district, with fine, old buildings and plenty of pedestrians on the sidewalk, but only light vehicle traffic.
The walkers then moved onto a path that led through a park-like setting for another half mile.
Finally, they ended their walk strolling through a busy, commercial district, with heavy automobile traffic and concrete buildings.
The walkers had been told to move at their own speed, not to rush or dawdle. Most finished the walk in about 25 minutes.
Throughout that time, the portable EEGs on their heads continued to feed information about brain wave patterns to the laptops they carried.
Afterward, the researchers compared the read-outs, looking for wave patterns that they felt were related to measures of frustration, directed attention (which they called “engagement”), mental arousal and meditativeness or calm.
What they found confirmed the idea that green spaces lessen brain fatigue.
When the volunteers made their way through the urbanized, busy areas, particularly the heavily trafficked commercial district at the end of their walk, their brain wave patterns consistently showed that they were more aroused, attentive and frustrated than when they walked through the parkland, where brain-wave readings became more meditative.
While traveling through the park, the walkers were mentally quieter.
Which is not to say that they weren’t paying attention, said Jenny Roe, a professor in the School of the Built Environment at Heriot-Watt University, who oversaw the study. “Natural environments still engage” the brain, she said, but the attention demanded “is effortless. It’s called involuntary attention in psychology. It holds our attention while at the same time allowing scope for reflection,” and providing a palliative to the nonstop attentional demands of typical, city streets.
Of course, her study was small, more of a pilot study of the nifty new, portable EEG technology than a definitive examination of the cognitive effects of seeing green.
But even so, she said, the findings were consistent and strong and, from the viewpoint of those of us over-engaged in attention-hogging urban lives, valuable. The study suggests that, right about now, you should consider “taking a break from work,” Dr. Roe said, and “going for a walk in a green space or just sitting, or even viewing green spaces from your office window.” This is not unproductive lollygagging, Dr. Roe helpfully assured us. “It is likely to have a restorative effect and help with attention fatigue and stress recovery.”
-by Gretchen Reynolds, The New York Times
EEG Identifies Seizures in Hospital Patients
Electroencephalogram (EEG), which measures and records electrical activity in the brain, is a quick and efficient way of determining whether seizures are the cause of altered mental status (AMS) and spells, according to a study by scientists at the UC San Francisco.
The research, which focused on patients who had been given an EEG after being admitted to the hospital for symptoms such as AMS and spells, appears on March 27 in Mayo Clinic Proceedings.
“We have demonstrated a surprisingly high frequency of seizures – more than 7 percent – in a general inpatient population,” said senior investigator John Betjemann, MD, a UCSF assistant professor of neurology. “This tells us that EEG is an underutilized diagnostic tool, and that seizures may be an underappreciated cause of spells and AMS.”
The results are important, he said, because EEG can identify treatable causes of AMS or spells, and because “it can prompt the physician to look for an underlying reason for seizures in persons who did previously have them.”
Seizures are treatable with a number of FDA-approved anticonvulsants, he said, “so patients who are quickly diagnosed can be treated more rapidly and effectively. This may translate to shorter lengths of stay and improved patient outcomes.”
In one of the first studies of its kind, Betjemann and his team analyzed the medical records of 1,048 adults who were admitted to a regular inpatient unit of a tertiary care hospital and who underwent an EEG. They found that 7.4 percent of the patients had a seizure of some kind while being monitored.
“As I tell my patients, seizures come in all different flavors, from a dramatic convulsion to a subtle twitching of the face or hand or finger,” said Betjemann. “There might be no outward manifestation at all, other than that the person seems a little spacey. It’s easily missed by family members and physicians alike, but can be picked up by EEG.”
Another 13.4 percent of patients had epileptiform discharges, which are abnormal patterns that indicate patients are at an increased risk of seizures.
Almost 65 percent of patients had their first seizure within one hour of EEG recording, and 89 percent within six hours.
“This is good news for smaller hospitals that don’t have 24 hour EEG coverage, but that do have a technician on duty during the day,” Betjemann said.
He speculated that lack of 24-hour coverage is a major reason that EEG is not used as an inpatient diagnostic tool as often as it might be. “This paper shows that, fortunately, it’s not necessary. Almost two thirds of patients with seizures can be identified in the first hour, and almost 90 percent in the course of a shift.”
EEGs are easy to obtain, painless and noninvasive, said Betjemann. “The technician applies some paste and electrodes and hooks up the machine. All the patient has to do is rest in bed.”
Betjemann said that the next logical research step would be a prospective study. “We have to start at the beginning, see if patients are altered when they are admitted, and do an EEG in a formal standardized setting. Then we’d want to see how often EEG is changing the management of patients – either starting or stopping medications,” he said. “A patient may be having spells, and an EEG might tell you this is not a seizure, and that it’s important not to treat it with anti-epileptic medications.”
(Image: Rex Features)
Meet London’s Babylab, where scientists experiment on babies’ brains
In the laboratories of the Henry Wellcome Building at Birkbeck, University of London, children’s squeaky toys lie scattered on the floor. Brightly coloured posters of animals are pasted on the walls and picture books are stacked on the low tables. This is the Babylab — a research centre that experiments on children aged one month to three years, to understand how they learn, develop and think. “The way babies’ brains change is an amazing and mysterious process,” says the lab director, psychologist Mark Johnson. “The brain increases in size by three- to four-fold between birth and teenage years, but we don’t understand how that relates to its function.”
The Birkbeck neuroscientists are interested in finding out how babies recognise faces, how they learn to pay attention to some things and not others, how they perceive emotion and how their language develops. Studies published by the lab have shown that babies prefer to look at faces over objects. They have also found that differences in the dopamine-producing gene can affect babies’ attention span and that at six to eight months of age, there are detectable differences in the brain patterns of babies who were later diagnosed with autism.
The biggest obstacle is designing the right kinds of experiment. “There aren’t many methods for getting inside the mind of an infant or a toddler,” Johnson explains. Graduate students at the Babylab have teamed up with technology companies, using a €1.9 million (£1.7 million) grant from the European Union, to develop tools such as EEG head nets that record electrical brain activity, helmets that use light to measure blood flow in different parts of the brain, and eye-trackers that help study attention. Eventually, they want to create wireless systems so babies can react and play naturally during experiments. But despite the wires, “all our studies are geared towards making sure our babies are contented,” says Johnson. “If we want data, we need happy babies.”
‘Brain waves’ challenge area-specific view of brain activity
Our understanding of brain activity has traditionally been linked to brain areas – when we speak, the speech area of the brain is active. New research by an international team of psychologists led by David Alexander and Cees van Leeuwen (Laboratory for Perceptual Dynamics) shows that this view may be overly rigid. The entire cortex, not just the area responsible for a certain function, is activated when a given task is initiated. Furthermore, activity occurs in a pattern: waves of activity roll from one side of the brain to the other.
The brain can be studied on various scales, researcher David Alexander explains: “You have the neurons, the circuits between the neurons, the Brodmann areas – brain areas that correspond to a certain function – and the entire cortex. Traditionally, scientists looked at local activity when studying brain activity, for example, activity in the Brodmann areas. To do this, you take EEG’s (electroencephalograms) to measure the brain’s electrical activity while a subject performs a task and then you try to trace that activity back to one or more brain areas.”
Activity waves
In this study, the psychologists explore uncharted territory: “We are examining the activity in the cerebral cortex as a whole. The brain is a non-stop, always-active system. When we perceive something, the information does not end up in a specific part of our brain. Rather, it is added to the brain’s existing activity. If we measure the electrochemical activity of the whole cortex, we find wave-like patterns. This shows that brain activity is not local but rather that activity constantly moves from one part of the brain to another. The local activity in the Brodmann areas only appears when you average over many such waves.”
Each activity wave in the cerebral cortex is unique. “When someone repeats the same action, such as drumming their fingers, the motor centre in the brain is stimulated. But with each individual action, you still get a different wave across the cortex as a whole. Perhaps the person was more engaged in the action the first time than he was the second time, or perhaps he had something else on his mind or had a different intention for the action. The direction of the waves is also meaningful. It is already clear, for example, that activity waves related to orienting move differently in children – more prominently from back to front – than in adults. With further research, we hope to unravel what these different wave trajectories mean.”