Posts tagged neuroscience
Articles and news from the latest research reports.
Bad decisions arise from faulty information, not faulty brain circuits
Making decisions involves a gradual accumulation of facts that support one choice or another. A person choosing a college might weigh factors such as course selection, institutional reputation and the quality of future job prospects.
But if the wrong choice is made, Princeton University researchers have found that it might be the information rather than the brain’s decision-making process that is to blame. The researchers report in the journal Science that erroneous decisions tend to arise from errors, or “noise,” in the information coming into the brain rather than errors in how the brain accumulates information.
These findings address a fundamental question among neuroscientists about whether bad decisions result from noise in the external information — or sensory input — or because the brain made mistakes when tallying that information. In the example of choosing a college, the question might be whether a person made a poor choice because of misleading or confusing course descriptions, or because the brain failed to remember which college had the best ratings.
Previous measurements of brain neurons have indicated that brain functions are inherently noisy. The Princeton research, however, separated sensory inputs from the internal mental process to show that the former can be noisy while the latter is remarkably reliable, said senior investigator Carlos Brody, a Princeton associate professor of molecular biology and the Princeton Neuroscience Institute (PNI), and a Howard Hughes Medical Institute Investigator.
"To our great surprise, the internal mental process was perfectly noiseless. All of the imperfections came from noise in the sensory processes," Brody said. Brody worked with first author Bingni Brunton, now a postdoctoral research associate in the departments of biology and applied mathematics at the University of Washington; and Matthew Botvinick, a Princeton associate professor of psychology and PNI.
The research subjects — four college-age volunteers and 19 laboratory rats — listened to streams of randomly timed clicks coming into both the left ear and the right ear. After listening to a stream, the subjects had to choose the side from which more clicks originated. The rats had been trained to turn their noses in the direction from which more clicks originated.
The test subjects mostly chose the correct side but occasionally made errors. By comparing various patterns of clicks with the volunteers’ responses, researchers found that all of the errors arose when two clicks overlapped, and not from any observable noise in the brain system that tallied the clicks. This was true in experiment after experiment utilizing different click patterns, in humans and rats.
The researchers used the timing of the clicks and the decision-making behavior of the test subjects to create computer models that can be used to indicate what happens in the brain during decision-making. The models provide a clear window into the brain during the “mulling over” period of decision-making, the time when a person is accumulating information but has yet to choose, Brody said.
"Before we conducted this study, we did not have a way of looking at this process without inserting electrodes into the brain," Brody said. "Now thanks to our model, we have an estimation of what is going on at each moment in time during the formation of the decision."
The study suggests that information represented and processed in the brain’s neurons must be robust to noise, Brody said. “In other words, the ‘neural code’ may have a mechanism for inherent error correction,” he said.
"The new work from the Brody lab is important for a few reasons," said Anne Churchland, an assistant professor of biological sciences at Cold Spring Harbor Laboratory who studies decision-making and was not involved in the study. "First, the work was very innovative because the researchers were able to study carefully controlled decision-making behavior in rodents. This is surprising in that one might have guessed rodents were incapable of producing stable, reliable decisions that are based on complex sensory stimuli.
"This work exposed some unexpected features of why animals, including humans, sometimes make incorrect decisions," Churchland said. "Specifically, the researchers found that errors are mostly driven by the inability to accurately encode sensory information. Alternative possibilities, which the authors ruled out, included noise associated with holding the stimulus in mind, or memory noise, and noise associated with a bias toward one alternative or the other."
(Source: princeton.edu)
Taste of beer, without effect from alcohol, triggers dopamine release in the brain
The taste of beer, without any effect from alcohol itself, can trigger dopamine release in the brain, which is associated with drinking and other drugs of abuse, according to Indiana University School of Medicine researchers.
Using positron emission tomography (PET), the researchers tested 49 men with two scans, one in which they tasted beer, and the second in which they tasted Gatorade, looking for evidence of increased levels of dopamine, a brain neurotransmitter long associated with alcohol and other drugs of abuse. The scans showed significantly more dopamine activity following the taste of beer than the sports drink. Moreover, the effect was significantly greater among participants with a family history of alcoholism.
Results of the study were published online Monday by the journal Neuropsychopharmacology.
"We believe this is the first experiment in humans to show that the taste of an alcoholic drink alone, without any intoxicating effect from the alcohol, can elicit this dopamine activity in the brain’s reward centers," said David A. Kareken, Ph.D., professor of neurology at the IU School of Medicine and the deputy director of the Indiana Alcohol Research Center.
The stronger effect in participants with close alcoholic relatives suggests that the release of dopamine in response to such alcohol-related cues may be an inherited risk factor for alcoholism, said Dr. Kareken.
Research for several decades has linked dopamine to the consumption of various drugs of abuse, although researchers have differing interpretations of the neurotransmitter’s role. Sensory cues that are closely associated with drug intoxication (ranging from tastes and smells to the sight of a tavern) have long been known to spark cravings and induce treatment relapse in recovering alcoholics. Many neuroscientists believe that dopamine plays a critical role in such cravings.
The study participants received a very small amount of their preferred beer — 15 milliliters — over a 15-minute time period, enabling them to taste the beer without resulting in any detectable blood alcohol level or intoxicating effect.
Using a PET scanning compound that targets dopamine receptors in the brain, the researchers were able to assess changes in dopamine levels occurring after the participants tasted the liquids.
In addition to the PET scan results, participants reported an increased beer craving after tasting beer, without similar responses after tasting the sports drink — even though many thought the Gatorade actually tasted better, said Brandon G. Oberlin, Ph.D., post-doctoral fellow and first author of the paper.
(Image: iStockphoto)
Ordinary Skin Cells Morphed into Functional Brain Cells
Scientists at CWRU School of Medicine Discover New Technique that Holds Promise for the Treatment of Multiple Sclerosis and Cerebral Palsy
Researchers at Case Western Reserve School of Medicine have discovered a technique that directly converts skin cells to the type of brain cells destroyed in patients with multiple sclerosis, cerebral palsy and other so-called myelin disorders.
This discovery appears today in the journal Nature Biotechnology.
This breakthrough now enables “on demand” production of myelinating cells, which provide a vital sheath of insulation that protects neurons and enables the delivery of brain impulses to the rest of the body. In patients with multiple sclerosis (MS), cerebral palsy (CP), and rare genetic disorders called leukodystrophies, myelinating cells are destroyed and cannot be replaced.
The new technique involves directly converting fibroblasts - an abundant structural cell present in the skin and most organs - into oligodendrocytes, the type of cell responsible for myelinating the neurons of the brain.
“Its ‘cellular alchemy,’” explained Paul Tesar, PhD, assistant professor of genetics and genome sciences at Case Western Reserve School of Medicine and senior author of the study. “We are taking a readily accessible and abundant cell and completely switching its identity to become a highly valuable cell for therapy.”
In a process termed “cellular reprogramming,” researchers manipulated the levels of three naturally occurring proteins to induce fibroblast cells to become precursors to oligodendrocytes (called oligodendrocyte progenitor cells, or OPCs).
Tesar’s team, led by Case Western Reserve researchers and co-first authors Fadi Najm and Angela Lager, rapidly generated billions of these induced OPCs (called iOPCs). Even more important, they showed that iOPCs could regenerate new myelin coatings around nerves after being transplanted to mice—a result that offers hope the technique might be used to treat human myelin disorders.
When oligodendrocytes are damaged or become dysfunctional in myelinating diseases, the insulating myelin coating that normally coats nerves is lost. A cure requires the myelin coating to be regenerated by replacement oligodendrocytes.
Until now, OPCs and oligodendrocytes could only be obtained from fetal tissue or pluripotent stem cells. These techniques have been valuable, but with limitations.
“The myelin repair field has been hampered by an inability to rapidly generate safe and effective sources of functional oligodendrocytes,” explained co-author and myelin expert Robert Miller, PhD, professor of neurosciences at the Case Western Reserve School of Medicine and the university’s vice president for research. “The new technique may overcome all of these issues by providing a rapid and streamlined way to directly generate functional myelin producing cells.”
This initial study used mouse cells. The critical next step is to demonstrate feasibility and safety using human cells in a lab setting. If successful, the technique could have widespread therapeutic application to human myelin disorders.
“The progression of stem cell biology is providing opportunities for clinical translation that a decade ago would not have been possible,” said Stanton Gerson, MD, professor of Medicine-Hematology/Oncology at the School of Medicine and director of the National Center for Regenerative Medicine and the UH Case Medical Center Seidman Cancer Center. “It is a real breakthrough.”
(Source: newswise.com)
Tapeworm-Linked Seizures May Be Rising in U.S.
Tapeworm infection in the brain that can trigger seizures is a growing health concern, doctors say.
But the infection, which leads to swelling in the brain, is usually treatable with medication, according to a leading association of neurologists.
Estimated cases of neurocysticercosis, as the tapeworm infection is called, range from 40,000 to 160,000 each year in the United States, said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston. “It’s been around a long time, affecting people living in severe poverty, but the disease is not well-studied or understood,” Hotez said.
Texas is one area of the country with many cases. “The disease has now become a leading cause of epilepsy in Houston,” Hotez said. “Every [week], we have patients come into our tropical medicine clinic with it.”
Concerns about an apparent increase of neurocysticercosis within the United States led the American Academy of Neurology to issue treatment guidelines for doctors and patients in the April 9 issue of the journal Neurology.
The recommendations are based on a review of 10 studies published between 1980 and 2010 that evaluated so-called cysticidal drugs for treatment of tapeworm infections. The infection involves infestation of the brain with the larvae of the Taenia solium tapeworm. In severe cases, it can cause death.
Tapeworm infection is common in Third World countries because of inadequate sanitation and hygiene, and an estimated 2 million people worldwide have epilepsy as a result. The good news is that good hygiene and food preparation can prevent it.
People develop the tapeworm infection when they consume improperly cooked meat, such as pork, or any food or drink that contains the tapeworm eggs or larvae (also known as cysts). Touching the fecal matter of an infected person is another means of transmission. The larvae then transform into full-sized tapeworms, which can grow to several feet, Hotez said.
In pigs, tapeworm larvae travel to the brain and await transmission to another animal (a human, for instance) when the pigs are eaten, he said. The parasites do the same thing in humans, but there’s nowhere to go from the human brain. Ultimately, the larvae die, and that’s when the trouble begins.
As the larvae die, they lose the ability to hide from the body’s immune system. The immune system responds by causing inflammation, which leads to epileptic seizures and brain swelling, Hotez said.
The guidelines for children and adults recommend using the medication albendazole to kill the cysts if they’re alive and treating brain swelling with corticosteroid drugs that dampen the immune system. The study found that albendazole (Albenza), used with or without the corticosteroids, reduced seizure frequency and the number of brain lesions seen in imaging scans. Not enough data was available to evaluate another drug, praziquantel, the researchers said.
Only limited evidence exists to support specific treatment approaches, however, and the treatments may produce side effects, such as abdominal complaints, according to the guidelines. It’s also unclear whether anti-epileptic medications may help prevent the seizures caused by the inflammation.
For now, the key is physician awareness, said Dr. Karen Roos, a professor of neurology at the Indiana University School of Medicine and lead author of the guidelines. “Physicians from areas of the world where this infection is endemic are very knowledgeable about this infection,” she said. “They know more than U.S. physicians.”
Infection with the tapeworm is preventable through proper sanitation, good hygiene and thorough cooking of meat.
(Source: nlm.nih.gov)
Babies’ brains to be mapped in the womb and after birth
UK scientists have embarked on a six-year project to map how nerve connections develop in babies’ brains while still in the womb and after birth.
By the time a baby takes its first breath many of the key pathways between nerves have already been made. And some of these will help determine how a baby thinks or sees the world, and may have a role to play in the development of conditions such as autism, scientists say.
But how this rich neural network assembles in the baby before birth is relatively unchartered territory.
Researchers from Guy’s and St Thomas’ Hospital, King’s College London, Imperial College and Oxford University aim to produce a dynamic wiring diagram of how the brain grows, at a level of detail that they say has been impossible until now.
They hope that by charting the journeys of bundles of nerves in the final three months of pregnancy, doctors will be able to understand more about how they can help in situations when this process goes wrong.
Prof David Edwards, director of the Centre for the Developing Brain, who is leading the research, says: “There is a distressing number of children in our society who grow up with problems because of things that happen to them around the time of birth or just before birth.
"It is very important to be able to scan babies before they are born, because we can capture a period when an awful lot is changing inside the brain, and it is a time when a great many of the things that might be going wrong do seem to be going wrong."
'Neural networks'
The study - known as the Developing Human Connectome Project - hopes to look at more than 1,500 babies, studying many aspects of their neurological development.
By examining the brains of babies while they are still growing in the womb, as well as those born prematurely and at full term, the scientists will try to define baselines of normal development and investigate how these may be affected by problems around birth.
And they plan to share their map with the wider research community.
Central to this project are advanced MRI scanning techniques, which the scientists say are able to pick up on details of the growing brain that have been difficult to capture until now.
While in the womb, foetuses are free to somersault in their amniotic sacs, and this constant movement has so far hindered clear images of growing brains.
But researchers at the Centre for the Developing Brain have found ways to counter the effects of these movements, building up full three-dimensional pictures while the foetus is in motion.
And by placing the MRI machine in the neonatal intensive care unit at Evelina Children’s Hospital in London they are one of the few centres in the world to have a scanner in such close proximity to the babies who often need it most, Prof Edwards says.
This means the same scanning system can be used to find out more about the brains of the sickest and smallest newborn babies, he says.
'Macro level'
Daniel Rueckert, professor of visual information processing at Imperial College London, who is also involved in the research, says: “We are trying to look at brain connectivity in two ways: firstly, from a structural perspective, to find out which parts of the brain are wired to other parts. And secondly we are looking at functional connectivity - how strongly two brain regions are linked across time and activity.”
But Prof Partha Mitra, a neuroscientist at Cold Spring Harbor Laboratory, New York state, says we need to be aware of the limitations of the technology in use.
"It would obviously be a very good thing to know more about the circuits in the developing human brain. Much of what we know hasn’t changed in a hundred years and has come from dissection studies.
"But we need to keep in mind the imaging techniques we have are indirect - we can’t open up a human brain and look at the connections while someone is alive so we rely on these non-invasive methods. But there is a big gap between the real circuits in the brain and what images can show us."
Prof Rueckert acknowledges that this map will provide a “macro-level” view of the developing brain and not be the “final answer”.
But he points to early results from the adult version of this project - the Human Connectome Project, based in the US: “There is so much evidence already from the adult project that there are significant changes in the brain that can be mapped with the technology we have now.
"It will be incredibly useful to be able to do this with the still growing and developing brain - perhaps giving us more time to intervene when things go wrong."
Children of Blind Mothers Learn New Modes of Communication
A loving gaze helps firm up the bond between parent and child, building social skills that last a lifetime. But what happens when mom is blind? A new study shows that the children of sightless mothers develop healthy communication skills and can even outstrip the children of parents with normal vision.
Eye contact is one of the most important aspects of communication, according to Atsushi Senju, a developmental cognitive neuroscientist at Birkbeck, University of London. Autistic people don’t naturally make eye contact, however, and they can become anxious when urged to do so. Children for whom face-to-face contact is drastically reduced—babies severely neglected in orphanages or children who are born blind—are more likely to have traits of autism, such as the inability to form attachments, hyperactivity, and cognitive impairment.
To determine whether eye contact is essential for developing normal communication skills, Senju and colleagues chose a less extreme example: babies whose primary caregivers (their mothers) were blind. These children had other forms of loving interaction, such as touching and talking. But the mothers were unable to follow the babies’ gaze or teach the babies to follow theirs, which normally helps children learn the importance of the eyes in communication.
Apparently, the children don’t need the help. Senju and colleagues studied five babies born to blind mothers, checking the children’s proficiency at 6 to 10 months, 12 to 15 months, and 24 to 47 months on several measures of age-appropriate communications skills. At the first two visits, babies watched videos in which a woman shifted her gaze or moved different parts of her face while corresponding changes in the baby’s face were recorded. Babies also followed the gaze of a woman sitting at a table and looking at various objects.
The babies also played with unfamiliar adults in a test that checked for autistic traits, such as the inability to maintain eye contact, not smiling in response to the adult’s smile, and being unable to switch attention from one toy to a new one. At each age, the researchers assessed the children’s visual, motor, and language skills.
When the results were compared to scores of children of “sighted” parents, the five children of blind mothers did just as well on the tests, the researchers report today in the Proceedings of the Royal Society B. Learning to communicate with their blind mothers also seemed to give the babies some advantages. For example, even at the youngest age tested, the babies directed fewer gazes toward their mothers than to adults with normal vision, suggesting that they were already learning that strangers would communicate differently than would their mothers. When they were between 12 and 15 months old, the babies of blind mothers were also more verbal than were other children of the same age. And the youngest babies of blind mothers outscored their peers in developmental tests—especially visual tasks such as remembering the location of a hidden toy or switching their attention from one toy to a new one presented by the experimenter.
Senju likens their skills to those of children who grow up bilingual; the need to shift between modes of communication may boost the development of their social skills, he says. “Our results suggest that the babies aren’t passively copying the expressions of adults, but that they are actively learning and changing the way to best communicate with others.”
"The use of sighted babies of blind mothers is a clever and important idea," says developmental scientist Andrew Meltzoff of the University of Washington’s Institute for Learning and Brain Sciences in Seattle. "The mother’s blindness may teach a child at an early age that certain people turn to look at things and others don’t. Apparently these little babies can learn that not everyone reacts the same way."
Meltzoff adds that there are many ways to pay attention to a child. “Doubtless, the blind mothers use touch, sounds, tugs on the arm, and tender pats on the back. Our babies want communication, love, and attention. The fact that these can come through any route is a remarkable demonstration of the adaptability of the human child.”
Reliability of neuroscience research questioned
New research has questioned the reliability of neuroscience studies, saying that conclusions could be misleading due to small sample sizes.
A team led by academics from the University of Bristol reviewed 48 articles on neuroscience meta-analysis which were published in 2011 and concluded that most had an average power of around 20 per cent – a finding which means the chance of the average study discovering the effect being investigated is only one in five.
The paper, being published in Nature Reviews Neuroscience, reveals that small, low-powered studies are ‘endemic’ in neuroscience, producing unreliable research which is inefficient and wasteful.
It focuses on how low statistical power – caused by low sample size of studies, small effects being investigated, or both – can be misleading and produce more false scientific claims than high-powered studies.
It also illustrates how low power reduces a study’s ability to detect any effects and shows that when discoveries are claimed, they are more likely to be false or misleading.
The paper claims there is substantial evidence that a large proportion of research published in scientific literature may be unreliable as a consequence.
Another consequence is that the findings are overestimated because smaller studies consistently give more positive results than larger studies. This was found to be the case for studies using a diverse range of methods, including brain imaging, genetics and animal studies.
Kate Button, from the School of Social and Community Medicine, and Marcus Munafò, from the School of Experimental Psychology, led a team of researchers from Stanford University, the University of Virginia and the University of Oxford.
She said: “There’s a lot of interest at the moment in improving the reliability of science. We looked at neuroscience literature and found that, on average, studies had only around a 20 per cent chance of detecting the effects they were investigating, even if the effects are real. This has two important implications - many studies lack the ability to give definitive answers to the questions they are testing, and many claimed findings are likely to be incorrect or unreliable.”
The study concludes that improving the standard of results in neuroscience, and enabling them to be more easily reproduced, is a key priority and requires attention to well-established methodological principles.
It recommends that existing scientific practices can be improved with small changes or additions to methodologies, such as acknowledging any limitations in the interpretation of results; disclosing methods and findings transparently; and working collaboratively to increase the total sample size and power.
(Source: bristol.ac.uk)
‘Seeing’ the flavor of foods
The eyes sometimes have it, beating out the tongue, nose and brain in the emotional and biochemical balloting that determines the taste and allure of food, a scientist said here today. Speaking at the 245th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society, he described how people sometimes “see” flavors in foods and beverages before actually tasting them.
“There have been important new insights into how people perceive food flavors,” said Terry E. Acree, Ph.D. “Years ago, taste was a table with two legs — taste and odor. Now we are beginning to understand that flavor depends on parts of the brain that involve taste, odor, touch and vision. The sum total of these signals, plus our emotions and past experiences, result in perception of flavors, and determine whether we like or dislike specific foods.”
Acree said that people actually can see the flavor of foods, and the eyes have such a powerful role that they can trump the tongue and the nose. The popular Sauvignon Blanc white wine, for instance, gets its flavor from scores of natural chemicals, including chemicals with the flavor of banana, passion fruit, bell pepper and boxwood. But when served a glass of Sauvignon Blanc tinted to the deep red of merlot or cabernet, people taste the natural chemicals that give rise to the flavors of those wines.
The sense of smell likewise can trump the taste buds in determining how things taste, said Acree, who is with Cornell University. In a test that people can do at home, psychologists have asked volunteers to smell caramel, strawberry or other sweet foods and then take a sip of plain water; the water will taste sweet. But smell bread, meat, fish or other non-sweet foods, and water will not taste sweet.
While the appearance of foods probably is important, other factors can override it. Acree pointed out that hashes, chilies, stews and cooked sausages have an unpleasant look, like vomit or feces. However, people savor these dishes based on the memory of eating and enjoying them in the past. The human desire for novelty and new experiences also is a factor in the human tendency to ignore what the eyes may be tasting and listening to the tongue and nose, he added.
Acree said understanding the effects of interactions between smell and vision and taste, as well as other odorants, will open the door to developing healthful foods that look and smell more appealing to finicky kids or adults.
(Source: portal.acs.org)
New therapy device enables stroke victims to recover further
Scientists from Nanyang Technological University (NTU) have developed a new stroke rehabilitation device which greatly improves recovery in stroke patients.
Thanks to this invention, stroke patients who had undergone conventional rehabilitation for a year or more and had hit a plateau in their recovery, managed to make significant progress in their ability to carry out everyday tasks.
Some of these long-term stroke sufferers have recovered up to 70 per cent of motor function clinical scores in just a month during the trial.
The new stroke therapy system, known as Synergistic Physio-Neuro Platform (SynPhNe), is currently undergoing thorough clinical investigations and more feasibility trials at local hospitals.
In use for 150 therapy hours, it has not had any side effects so far. Patients who tried SynPhNe also said they experienced little fatigue while using this easy-to-use system.
Developed by Dr John Heng, a senior research fellow at NTU’s School of Mechanical and Aerospace Engineering and his PhD student, Mr Banerji Subhasis, this system gives hope to frustrated patients who want to see more progress after completing conventional rehabilitation therapies.
The NTU research team of four has published over 11 scientific papers since 2008 on the principles of the system, its effectiveness and ease of use.
“While current rehabilitation systems do benefit many patients, there are also other patients who still have difficulties performing everyday activities like holding a fork or drinking from a cup, despite the usual rehab sessions,” said Dr Heng.
“SynPhNe works by giving real-time feedback to the patients on what is happening in their mind and in their muscles. Patients using SynPhNe know where their problems lie and can slowly work towards overcoming each problem, instead of feeling frustrated and going through a painful, expensive and prolonged trial-and-error process when their improvements are not visible.”
How it works
SynPhNe consists of patented computer software connected to a specially designed headset with neural sensors and a sensor arm glove. The device is designed to be worn easily by stroke patients who usually have control of only one arm.
These sensors provide feedback on the stress, attention, and relaxation levels of the mind and which muscles are being activated or inhibited by the patient. The software contains instructional videos for limb movements which the patient can mimic to improve his/her performance of various tasks.
Sensor information is displayed in real time via the computer screen so that the patient is aware of what is happening in his mind and body while undergoing the rehabilitation exercises.
Dr Heng said that while multi-model associative learning is known to be useful in the development of babies and in education, it is the first time that their research team is adapting it for stroke therapy. Tested on 10 patients so far, it has shown to be very effective in accelerating the recovery in stroke patients.
In associative learning, a patient will find out the link between cause and effect, or intent and physical result. The patient learns what he/she wants to do and what is actually happening with their limbs. This helps the patient to self-correct movements to match intended actions.
“For example, if a patient wants to move his wrist, but his wrist is not moving, SynPhNe will be able to show him that his mind had sent out a signal, his muscles have received it, but because supporting and opposing muscles are clenched, he will need to relax the opposing muscle in order to move his wrist,” Mr Subhasis explained.
“Another common problem is that the patient may feel stressed while undergoing therapy, which affects his muscle control. So by showing the stress level on the screen, SynPhNe will teach the patient how to control his breathing and posture to regain his balance and composure so that he can continue with the exercises.
“In short, SynPhNe makes patients aware of what is happening with their bodies so they learn how to relax their mind and muscles. This helps them to re-learn simple actions like holding a pen or a cup which may be arduous tasks for stroke victims.”
Ramping up patient trials
Patient trials are still on-going and 10 patients have undergone the trial for 12 sessions, each lasting 90 minutes. Over a four-week period, they have all shown some improvement on the clinical scales. It was found that patients with hand control and hand weakness problems improved the most, in several cases, up to 70 per cent.
The scientists started the patient trials in October 2012 at Tan Tock Seng Hospital and are embarking on another similar trial at the National University Hospital. Talks are underway to start another trial at Singapore General Hospital and in India.
SynPhNe, which took over five years to develop, have also won successive grants from the National Medical Research Council, the National Research Foundation’s Proof-of-Concept grant and Singapore-MIT Alliance for Research and Technology (SMART)’s Innovation Grant.
Start-up to look into commercialisation
Apart from conducting further trials involving 50 more patients, the next step for the scientists is to form a start-up company to turn the SynPhNe prototype into a portable stroke therapy kit for home use. This kit is expected to be cheaper than most robotic rehabilitation systems in the market which may cost over tens of thousands of dollars.
“This reduction in cost will allow for perhaps a rental or subsidy scheme for patients who wish to practise in the convenience of their own home instead of having to go to rehabilitation centres. It has the added advantage of providing constant updates of instructional videos and exercises to match the patient’s improvement and can even send their reports to their therapists via the device’s Wi-Fi capabilities,” Prof Heng added.
The idea to develop SynPhNe was inspired by the mind-and-body-as-one philosophy preached in traditional practices such as Taichi, Aikido and Yoga, and the health benefits they bring.
Mr Subhasis, a martial arts and yoga practitioner for more than 30 years had sought to bring this health benefit to people through modern yet simple, affordable technology. In the latest study, the patients who synergised their minds and bodies best (based on the brain and muscles signals recorded by SynPhNe) made the most dramatic improvements.
“Training the patients to self-regulate their mind and body increases their confidence to make positive changes in their lives. It also helps therapists better customize rehabilitation routines based on the individual patient’s capabilities and perceptions,” Mr Subhasis added.
The Singapore-MIT Alliance (SMART) and Technology Transfer Office at NTU (NIEO) are assisting the research group with the commercialisation process.
Reactivating memories during sleep
Why do some memories last a lifetime while others disappear quickly?
(Image: Tim Vernon, LTH NHS TRUST/SCIENCE PHOTO LIBRARY)
A new study suggests that memories rehearsed, during either sleep or waking, can have an impact on memory consolidation and on what is remembered later.
The new Northwestern University study shows that when the information that makes up a memory has a high value (associated with, for example, making more money), the memory is more likely to be rehearsed and consolidated during sleep and, thus, be remembered later.
Also, through the use of a direct manipulation of sleep, the research demonstrated a way to encourage the reactivation of low-value memories so they too were remembered later.
Delphine Oudiette, a postdoctoral fellow in the department of psychology at Northwestern and lead author of the study, designed the experiment to study how participants remembered locations of objects on a computer screen. A value assigned to each object informed participants how much money they could make if they remembered it later on the test.
"The pay-off was much higher for some of the objects than for others," explained Ken Paller, professor of psychology at Northwestern and co-author of the study. "In other words, we manipulated the value of the memories — some were valuable memories and others not so much, just as the things we experience each day vary in the extent to which we’d like to be able to remember them later."
When each object was shown, it was accompanied by a characteristic sound. For example, a tea kettle would appear with a whistling sound. During both states of wakefulness and sleep, some of the sounds were played alone, quite softly, essentially reminding participants of the low-value items.
Participants remembered the low-value associations better when the sound presentations occurred during sleep.
"We think that what’s happening during sleep is basically the reactivation of that information," Oudiette said. "We can provoke the reactivation by presenting those sounds, therefore energizing the low-value memories so they get stored better."
The research poses provocative implications about the role memory reactivation during sleep could play in improving memory storage,” said Paller, director of the Cognitive Neuroscience Program at Northwestern. “Whatever makes you rehearse during sleep is going to determine what you remember later, and conversely, what you’re going to forget.”
Many memories that are stored during the day are not remembered.
"We think one of the reasons for that is that we have to rehearse memories in order to keep them. When you practice and rehearse, you increase the likelihood of later remembering," Oudiette said. "And a lot of our rehearsal happens when we don’t even realize it — while we’re asleep."
Paller said selectivity of memory consolidation is not well understood. Most efforts in memory research have focused on what happens when you first form a memory and on what happens when you retrieve a memory.
"The in-between time is what we want to learn more about, because a fascinating aspect of memory storage is that it is not static," Paller said. "Memories in our brain are changing all of the time. Sometimes you improve memory storage by rehearsing all the details, so maybe later you remember better — or maybe worse if you’ve embellished too much.
"The fact that this critical memory reactivation transpires during sleep has mostly been hidden from us, from humanity, because we don’t realize so much of what’s happening while we’re asleep," he said.
(Source: eurekalert.org)