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brain activity
Scientists discovered that a surge of electrical activity in the brain could be responsible for the vivid experiences described by near-death survivors.
A study carried out on dying rats found high levels of brainwaves at the point of the animals’ demise.
US researchers said that in humans this could give rise to a heightened state of consciousness.
The research is published in the Proceedings of the National Academy of Sciences.
The lead author of the study, Dr. Jimo Borjigin, of the University of Michigan, said: “A lot of people thought that the brain after clinical death was inactive or hypoactive, with less activity than the waking state, and we show that is definitely not the case.
“If anything, it is much more active during the dying process than even the waking state.”
A surge of electrical activity in the brain could be responsible for the vivid experiences described by near-death survivors
From bright white lights to out-of-body sensations and feelings of life flashing before their eyes, the experiences reported by people who have come close to death but survived are common the world over.
However, studying this in humans is a challenge, and these visions are little understood.
To find out more, scientists at the University of Michigan monitored nine rats as they were dying.
In the 30-second period after the animal’s hearts stopped beating, they measured a sharp increase in high-frequency brainwaves called gamma oscillations.
These pulses are one of the neuronal features that are thought to underpin consciousness in humans, especially when they help to “link” information from different parts of the brain.
In the rats, these electrical pulses were found at even higher levels just after the cardiac arrest than when animals were awake and well.
Dr. Jimo Borjigin said it was feasible that the same thing would happen in the human brain, and that an elevated level of brain activity and consciousness could give rise to near-death visions.
“This can give us a framework to begin to explain these. The fact they see light perhaps indicates the visual cortex in the brain is highly activated – and we have evidence to suggest this might be the case, because we have seen increased gamma in area of the brain that is right on top of the visual cortex,” she said.
“We have seen increased coupling between the lower-frequency waves and the gamma that has been shown to be a feature of visual awareness and visual sensation.”
However, Dr. Jimo Borjigin said that to confirm the findings a study would have to be carried out on humans who have experienced clinical death and have been revived
Two leading doctors at an European meeting of anaesthetists urged for an international agreement on when and how death is diagnosed.
They said improvements in technology mean the line between life and death is less clear.
They also called for precise guidelines and more research to prevent the rare occasions when people are pronounced dead but are later found to be alive.
The World Health Organization (WHO) has begun work to develop a global consensus.
In the majority of cases in hospitals, people are pronounced dead only after doctors have examined their heart, lungs and responsiveness, determining there are no longer any heart and breath sounds and no obvious reaction to the outside world.
But Dr. Alex Manara, a consultant anaesthetist at Frenchay Hospital in Bristol, said more than 30 reports in medical literature, describing people who had been determined dead but later found to be alive, had driven scientists to question whether the diagnosis of death can be improved.
At a meeting of the European Society for Anaesthesiology he said that on some occasions doctors do not observe the body for long enough before someone is declared dead.
Two leading doctors at an European meeting of anaesthetists urged for an international agreement on when and how death is diagnosed
Dr. Alex Manara called for internationally agreed guidelines to ensure doctors observe the body for five minutes, in order not to miss anyone whose heart and lungs spontaneously recover.
Many institutions in the US and Australia have adopted two minutes as the minimum observation period, while the UK and Canada recommend five minutes. Germany currently has no guidelines and Italy proposes that physicians wait 20 minutes before declaring death, particularly when organ donation is being considered.
At the conference, Ricard Valero, professor of anaesthesia at the University of Barcelona, considered the rarer scenario of patients in intensive care units whose hearts and lungs are kept functioning by machines.
In such scenarios, doctors use the concept of brain death – often conducting neurological tests to monitor any brain activity in the patient.
But the criteria used to establish brain death have slight variations across the globe.
In Canada, for example, one doctor is needed to diagnose brain death; in the UK, two doctors are recommended; and in Spain three doctors are required. The number of neurological tests that have to be performed vary too, as does the time the body is observed before death is declared.
“These variations in practice just do not seem logical,” Prof. Ricard Valero said.
He proposed further research to support a global consensus on the most appropriate criteria to diagnose brain death.
Brain scans have allowed researchers to know exactly what a person was imagining after scientists used them to decode images directly from the brain.
Researchers have been able to put together what numbers people have seen, the memory a person is recalling, and even reconstruct videos of what a person has watched.
“We are trying to understand the physical mechanisms that allow us to have an inner world, and a part of that is how we represent other people in our mind,” said Cornell University cognitive neuroscientist Nathan Spreng.
Nathan Spreng’s team gave 19 volunteers descriptions of four imaginary people.
These characters had different personalities half being agreeable and cooperative and half being cold and aloof.
Half were described as outgoing and social and half were depicted as shy and inhibited.
Scientists matched the genders of these characters to each volunteer giving them names like Mike, Chris, Dave, or Nick, or Ashely, Sarah, Nicole, or Jenny for the women.
The volunteer’s brains were then scanned using functional magnetic resonance imaging. The technology measures brain activity by changes in blood flow.
Volunteers were then asked to picture how the characters might react in different scenarios, such as if they saw a homeless veteran asking for change or if they were at a bar and someone else spilled a drink.
“Humans are social creatures, and the social world is a complex place,” Nathan Spreng told Business Insider.
“A key aspect to navigating the social world is how we represent others.”
Brain scans allow researchers to know exactly what a person is imagining
Brain activity in picturing each personality was linked to a unique pattern of brain activity in the medial prefrontal cortex.
“This is the first study to show that we can decode what people are imagining,” Nathan Spreng said.
That area of the brain helps people deduce traits about others and the findings suggest it’s also the region where personality models are encoded, assembled, and updated.
“The scope of this is incredible when you think of all the people you meet over the course of your life and are able to remember. Each one probably has its own unique representation in the brain,” Nathan Spreng said.
“This representation can be modified as we share experiences and learn more about each other, and plays into how we imagine future events with others unfolding.”
The area is also linked to autism and disorders that inhibit people in social interactions.
People with these disorders may not be able to build accurate personality models of other people.
These advances could someday help treat these disorders.
Former Israeli PM Ariel Sharon, who has been in a coma for seven years, has shown significant signs of brain activity, doctors say.
A team of Israeli and American scientists say new tests showed Ariel Sharon, 84, responded to external stimuli.
The activity increased when he was being shown pictures of his family and played a recording of his son’s voice.
Ariel Sharon has been in a coma since 2006, when he suffered a massive stroke.
Since then, he has been in a vegetative state, connected to a respirator.
The doctors at Soroka Hospital in Beersheba said that during tests, “significant brain activity was observed… indicating appropriate processing of these stimulations.”
While the responses did not mean Ariel Sharon was likely to fully regain consciousness, doctors said they were “encouraging”.
Alon Friedman, a neurological director at Israel’s Soroka Medical Centre in Beersheba, said the findings suggested that even in Ariel Sharon’s comatose state, “he might be listening, and some important information goes into his brain and is being processed”.
Former Israeli PM Ariel Sharon, who has been in a coma for seven years, has shown significant signs of brain activity
Ariel Sharon was a storied military officer who fought in three wars before entering politics.
He was admired by many Israelis as a great military leader, but reviled by Palestinians.
Ariel Sharon was elected prime minister in 2001, pledging to achieve “security and true peace”, and served until his stroke in 2006.
In 2005, he unilaterally withdrew Israeli troops and settlers from Gaza.
Ariel Sharon was a keen promoter of the expansion of the building and expansion of settlements in the occupied territories. He also initiated the construction of the separation barrier along the border and inside the West Bank.
But late in his career, despite fierce opposition in Israel, he ordered Jewish settlers to leave Gaza and four settlements in the West Bank.
As defence minister, Ariel Sharon masterminded Israel’s invasion of Lebanon in 1982. During the invasion, Lebanese Christian militiamen allied to Israel massacred hundreds of Palestinians in two refugee camps under Israeli control.
Scott Routley, a Canadian man who was believed to have been in a vegetative state for more than a decade, has been able to tell scientists that he is not in any pain.
It’s the first time an uncommunicative, severely brain-injured patient has been able to give answers clinically relevant to their care.
Scott Routley, 39, was asked questions while having his brain activity scanned in an fMRI machine.
His doctor says the discovery means medical textbooks will need rewriting.
Vegetative patients emerge from a coma into a condition where they have periods awake, with their eyes open, but have no perception of themselves or the outside world.
Scott Routley suffered a severe brain injury in a car accident 12 years ago.
None of his physical assessments since then have shown any sign of awareness, or ability to communicate.
But the British neuroscientist Prof. Adrian Owen – who led the team at the Brain and Mind Institute, University of Western Ontario – said Scott Routley was clearly not vegetative.
“Scott has been able to show he has a conscious, thinking mind. We have scanned him several times and his pattern of brain activity shows he is clearly choosing to answer our questions. We believe he knows who and where he is.”
Scott Routley, a Canadian man who was believed to have been in a vegetative state for more than a decade, has been able to tell scientists that he is not in any pain
Prof. Adrian Owen said it was a groundbreaking moment.
“Asking a patient something important to them has been our aim for many years. In future we could ask what we could do to improve their quality of life. It could be simple things like the entertainment we provide or the times of day they are washed and fed.”
Scott Routley’s parents say they always thought he was conscious and could communicate by lifting a thumb or moving his eyes. But this has never been accepted by medical staff.
Prof. Bryan Young at University Hospital, London – Scott Routley’s neurologist for a decade – said the scan results overturned all the behavioral assessments that had been made over the years.
“I was impressed and amazed that he was able to show these cognitive responses. He had the clinical picture of a typical vegetative patient and showed no spontaneous movements that looked meaningful.”
Observational assessments of Scott Routley since he responded in the scanner have continued to suggest he is vegetative. Prof. Bryan Young said medical textbooks would need to be updated to include Prof. Adrian Owen’s techniques.
Another Canadian patient, Steven Graham, was able to demonstrate that he had laid down new memories since his brain injury. Steven Graham answers yes when asked whether his sister has a daughter. His niece was born after his car accident five years ago.
The Panorama team also followed three patients at the Royal Hospital for Neuro-disability (RHN) in Putney, which specializes in the rehabilitation of brain-injured patients.
It collaborates with a team of Cambridge University neuroscientists at the Wolfson Brain Imaging Centre at Addenbrooke’s hospital, Cambridge.
One of the patients is diagnosed as vegetative by the RHN, and he is also unable to show awareness in an fMRI machine.
A second patient, who was not able to be fully assessed by the RHN because of repeated sickness, is later shown to have some limited awareness in brain scans.
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A scientific research paper claims to have discovered that your body can predict the future.
Scientist believe that during tests they have found proof that people can anticipate events, or realize that something about to happen, without any cues.
The paper, in the Frontiers of Perception Science journal, says that after studying people’s reactions in 26 different tests, they found that subjects could “predict” that something out of the ordinary was about to happen.
Julia Mossbridge, from Northwestern University in Illinois, Patrizio Tressoldi, from the Università di Padova, Italy and Jessica Utts, from the University of California, compiled the test.
They showed random images, some which were neutral and some designed to stimulate.
They discovered a “presentiment” effect, which measures physiological excitement that change seconds before an event.
A scientific research paper claims to have discovered that your body can predict the future
People’s reactions happened up to ten seconds before the event occurred, suggesting people can predict the future.
The finding suggests that people’s bodies subconsciously sense the future when something important is about to happen, even if the people don’t know it, Live Science reported.
They measured excitement by studying pupils dilating, heart rates quickening, blood volume and brain activity.
Scientists Julia Mossbridge, from Northwestern University in Illinois, Patrizio Tressoldi, from the Università di Padova, Italy and Jessica Utts, from the University of California, compiled the test.
Julia Mossbridge said that they do not believe it is supernatural phenomena, rather scientific laws that nobody understands as of yet.
However, other scientists are skeptical of the findings, Live Science reported.
One scientist said that the findings showed scientists were looking for evidence of “presentiment” and did not actually prove that it existed.
Another researcher said it could be that the examinations were unintentionally biased which researchers had failed to spot.
Scientists from Finland have located a certain area of the brain that could be responsible for weight gain and obesity.
The central nervous system helps to control food intake and it has long been known that the brain influences how and what we eat.
However, the latest finding suggest overweight individuals’ brains could be wired in such a way that they “constantly generate signals that promote eating” even when they don’t require food.
Participants to the study were exposed to images of food while their brain activity was monitored using functional MRI scans.
The results showed that morbidly obese subjects had a significantly higher glucose metabolism in the striatal region of the brain than lean participants.
This region is responsible for rewarding emotions and desires.
Scientists from Finland have located a certain area of the brain that could be responsible for weight gain and obesity
These findings are yet another step towards understanding how brain responses vary in people with weight problems.
Lead researcher Professor Lauri Nummenmaa from the University of Turku said: “The results suggest that obese individuals’ brains might constantly generate signals that promote eating even when the body would not require additional energy uptake.”
It is now hoped that the discovery will help develop more effective obesity intervention strategies.
Prof. Lauri Nummenmaa, who worked with a team from Aalto University, added: “The results have major implications on the current models of obesity, but also on development of pharmacological and psychological treatments of obesity.”
A previous study from Cambridge University found leptin, one of the key hormones responsible for reducing hunger and increasing the feeling of fullness, also controls fondness for food.
Patients with a rare genetic disorder resulting in a complete lack of leptin receptors in the brain were found to eat excessively and develop severe obesity.
When they were treated with the hormone, scientists found their hunger was reduced, and they gradually lost weight.
Although obesity typically results simply from excessive calorie intake, it is still unclear why some people are prone to overeating and gaining weight.
The results of the recent study appeared in the journal PLoS ONE.
Obesity is when a person is carrying too much body fat for their height and gender and a person is considered obese if they have a body mass index (BMI) of 30 or more.
An international team of researchers says it may be possible to detect autism at a much earlier age than previously thought.
The team’ study findings, published in Current Biology, identified differences in infants’ brainwaves from as early as six months.
Behavioral symptoms of autism typically develop between a child’s first and second birthdays.
Autism charities said identifying the disorder at an earlier stage could help with treatment.
It is thought that one in every 100 children has an autism spectrum disorder in the UK. The disorder affects more boys than girls. While there is no “cure”, education and behavioral programmes can help. The overall effect of these programs is greatly increased when autism is detected at a young age. One of the first things the parent of an autistic child may notice is that they have problems in social situations. Difficulty with conversation, trouble making friends, and obsessive-compulsive behavior are all early signs of autism. It should also be noted that these signs are not guarantees that one is in the early stages of the disorder, but if the problems are persistent then it would be wise to take the child to a specialist.
One of the researchers, Prof. Mark Johnson from Birkbeck College, University of London, said:
“The prevailing view is that if we are able to intervene before the onset of full symptoms, such as a training programme, at least in some cases we can maybe alleviate full symptoms.”
An international team of researchers says it may be possible to detect autism at a much earlier age than previously thought
Prof. Mark Johnson’s team looked for the earliest signs of autism in 104 children aged between six and 10 months. Half were known to be at risk of the disorder because they had on older sibling who had been diagnosed with autism. The rest were low risk.
Older children with autism can show a lack of eye contact, so the babies were shown pictures of people’s faces that switched between looking at or away from the baby.
Sensors attached to the scalp looked for differences in brain activity.
In low-risk babies, or high-risk babies that did not develop autism, there was a large difference in the brainwaves when looking at each type of image.
There was a much smaller difference in the brainwaves of babies who developed autism.
Prof. Mark Johnson said: “It is important to note it is not a 100% predictor. We had babies who flagged up warning signs who did not develop autism.”
There were also babies who did develop autism who had low-risk brainwaves. The test would need to be more accurate before it was used routinely.
Prof. Tony Charman, Centre for Research in Autism and Education at the Institute of Education, said: “Differences in the use of eye gaze to regulate social interaction are already a well-recognized early feature in many children with autism from the second year of life.
“Future studies will be required to determine whether measurements of brain function such as those used in our study might one day play a role in helping to identify children at an even earlier age.”
Christine Swabey from the charity Autistica said: “The hope is that this important research will lead to improved identification and access to services for future generations.
“Ultimately, the earlier we can identify autism and provide early intervention, the better the outcomes will be.”
Dr. Georgina Gomez-de-la-Cuesta from the National Autistic Society said: “Further research to investigate these differences will eventually lead to earlier recognition of the condition.
“Early intervention is very effective in supporting those with autism, so recognition in infancy can only be beneficial in helping individuals with autism reach their full potential.
“However, this important research is still in its early stages, and larger studies looking at several early markers of autism will be necessary before a robust clinical diagnosis could be possible at such a young age.”
