How addictive drugs influence learning and memory

Washington, Sep 10 (ANI): In a new study on mice, researchers have found why and how the use of addictive drugs take control of reward signals and influence neural processes associated with learning and memory.

The study could help explain how drug-associated memories, such as the place of drug use, drive and perpetuate the addiction.

It is known that the neurochemical dopamine, a key player in the brain’s reward system, is involved in the process of addiction.

Research has indicated that dopamine participates in neural processes associated with learning, such as the strengthening of neuronal connections, called synaptic potentiation.

Evidence has also implicated the hippocampus, a deep-brain structure that is critical for formation of new memories, in the development of drug addiction.

“Although addictive drugs like nicotine have been shown to influence the induction of synaptic potentiation, there has been little or no research in freely moving animals that monitors ongoing induction of synaptic potentiation by a biologically relevant drug dose,” explains senior author Dr. John Dani from the Department of Neuroscience at the Baylor College of Medicine in Houston, Texas.

The researchers recorded from the brains of freely moving mice while applying physiologically relevant concentrations of nicotine, the addictive component in tobacco.

The researchers found that nicotine induced synaptic potentiation correlated with the mice learning to prefer a place associated with the nicotine dose.

Importantly, these effects required a local dopamine signal within the hippocampus.

The finding reinforces the view that dopamine enables memory for specific events.

Overall, the results point to some intriguing possibilities about how drug-associated memories might contribute to behaviors associated with addiction.

“An animal’s memories or feelings about the environment are updated when the dopamine signal labels a particular event as important, new, and salient. Normally these memories help us to perform successful behaviors, but in our study, those memories were linked to the addictive drug.

When specific environmental events occur, such as the place or people associated with drug use, they are capable of cuing drug-associated memories or feelings that motivate continued drug use or relapse,” concluded Dani.

The study has been published in the latest issue of the journal Neuron. (ANI)

Same neural networks in brain process familiar and newly learnt words

Washington, August 29 (ANI): A series of experiments conducted as part of the Academy of Finland’s Neuroscience Research Programme (NEURO) have shown that the brain uses the same neural networks to process both familiar and newly learnt words.

In one experiment, participants learnt the name and/or purpose of 150 ancient tools. They had never heard those words before.

Their brain function was measured by means of magnetoencelography during the naming of the tools, both before and after the learning period.

It was observed that their brains used the same neural networks to process both familiar and newly learned words.

Academy Professor Riitta Salmelin, HUT Low Temperature Laboratory, who is in charge of the research, revealed that the names of objects were processed in the left temporal and frontal lobe within half a second of showing the image of the tool to the subject.

“If the subject had only recently learned the name of the tool, the naming process induced an activation that was just as strong or stronger than the activation induced by the image of a familiar object,” the researcher said.

Salmelin added that the learning of the meaning of ancient tools did not cause corresponding clear differences in the function of the brain.

According to the researcher, it seems that the processing of meanings in the brain differs essentially from the processing of names.

On the other hand, said Salmelin, the performance results indicated that new definitions were learnt even faster than new names.

The research team are now working on a follow-up study to explore the retention of learned words.

“We are also conducting a separate series of experiments to find out how our brain learns phonetic structures and, on the other hand, how the brain learns to identify letter combinations that are typical of a certain language,” Salmelin said.

Another area of interest in the ongoing study is the role of grammar in language learning.

The researchers say that they will try to explore how the brain learns to use the vocabulary and grammatical structure of an experimental miniature language. (ANI)

Novel method to make safer human stem cells uses just one gene

London, Aug 29 (ANI): Inching closer to curing diseases like Parkinson’s using cells generated from a patient’s own body, researchers have successfully reprogrammed human nerve cells back to an embryo-like state by using just a single gene.

It is known that embryonic stem cells are pluripotent – they can develop into any of the body’s cell types.

But such cells are not available in large numbers, as they can only be harvested from a donated egg or embryo, and, for ethical reasons, most countries have laws restricting their use.

In 2006, Shinya Yamanaka and his colleagues at Kyoto University in Japan successfully made mouse cells pluripotent by reprogramming skin cells into a state like embryo cells.

They did so by using retroviruses to insert four genes – known as “factors” – into the cells’ DNA.

They repeated the trick a year later with human cells.

However, using genes and retroviruses in this way increases the risk of the cell becoming cancerous, not just because tinkering with DNA has that effect, but also because two of the four factors are known to cause cancer.

In a bid to make these promising cells in a safe way, Hans Scholer’s team at the Max Planck Institute for Molecular Biomedicine in Münster, Germany, has been working to achieve pluripotency using fewer factors.

Last year, they did this with the two factors that do not cause cancer, and now they have simplified the recipe further, doing it with just one.

“Remarkably, it turns out that three of these four essential factors are already expressed in human neural stem cells – although not in skin cells – so we only needed to add one factor, OCT4,” New Scientist quoted Boris Greber, a member of the team, as saying.

He said that the cells from neural tissue are much easier to reprogram than skin cells, and are less prone to mutations.

It is much harder to get a sample of neural stem cells than skin cells, as it can be done via extracting the cells from the dental pulp of teeth, said Greber.

Inserting even one gene into the chromosome of a cell still permanently modifies its DNA, which is why the new method will remain a lab tool instead of being allowed in the clinic.

However, the researchers are hoping that it will help them improve methods for producing embryonic stem cells.

“Ideally, we will be able to find a chemical that does the same job of expressing the factor without the need for a gene,” said Greber.

Earlier this year, researchers in California managed just that when they reprogrammed mouse fibroblasts using a cocktail of proteins.

That technique did not involve inserting genes, and, thus, shouldn’t raise the cancer risk. But that was far less efficient.

“Without stable intervention using viruses, the frequency of reprogramming goes down and you have to wait a long time. We don’t have the perfect method yet,” said Greber.

The study has been published in the journal Nature. (ANI)

Nighttime alertness probed

Washington, Aug 27 (ANI): A new study, conducted by researchers in the U.S., has shown that the circadian system is not the only pathway involved in determining alertness at night – red light, which does not stimulate the circadian system, is just as effective at increasing nighttime alertness as blue light, which does.

Mariana Figueiro from Rensselaer Polytechnic Institute, New York, and colleagues examined the effects of the different lighting conditions.

“It is now well accepted that the circadian system is maximally sensitive to short-wavelength (blue) light and is quite insensitive to long-wavelength (red) light. We’ve shown that a moderate level of red light impacts alertness, an effect that must occur via a pathway other than the circadian system,” she said.

Circadian rhythms are roughly 24-hour cycles in various biological processes, such as core body temperature, melatonin synthesis and sleep-wake behavior, that repeat approximately every 24 hours and are synchronized most strongly by the light-dark cycle in the environment.

Bright light is known to increase alertness at night, but it has never been completely clear whether this light-induced alertness can arise from neural pathways other than those involved in the circadian system.

“There is previous compelling evidence that light-induced stimulation of the circadian system increases alertness at night, but our results suggest that this effect is mediated not only by the circadian system, but also through other mechanisms,” Figueiro added.

The research has been described in the open access journal BMC Neuroscience. (ANI)

Why we sleep – ‘science-wise’

London, Aug 21 (ANI): From animals to humans, everybody requires a good night sleep. However, the function of sleep still remains one of the greatest unsolved mysteries of science, say researchers.

While many theories suggest that sleep helps in brain “maintenance” – including memory consolidation and pruning- reverse damage from oxidative stress suffered while awake and promote longevity, none of them are well established.

Now, researchers from University of California, Los Angeles have come up with a new theory that sleep’s primary function is to increase animals’ efficiency and minimize their risk by regulating the duration and timing of their behaviour.

“Sleep has normally been viewed as something negative for survival because sleeping animals may be vulnerable to predation and they can’t perform the behaviors that ensure survival,” Nature quoted Jerome Siegel, professor of psychiatry and director of the Centre for Sleep Research at the Semel Institute for Neuroscience and Human Behaviour at UCLA as saying,iegel said.

“These behaviours include eating, procreating, caring for family members, monitoring the environment for danger and scouting for prey.

“So it’s been thought that sleep must serve some as-yet unidentified physiological or neural function that can’t be accomplished when animals are awake,” he added.

In the study conducted using platypus, walrus, and echidna – a small, burrowing, egg-laying mammal covered in spines, the researchers showed that sleep itself is highly adaptive, much like the inactive states seen in a wide range of species, starting with plants and simple microorganisms; these species have dormant states – as opposed to sleep – even though in many cases they do not have nervous systems.

That challenges the idea that sleep is for the brain, said Siegel.

“We see sleep as lying on a continuum that ranges from these dormant states like torpor and hibernation, on to periods of continuous activity without any sleep, such as during migration, where birds can fly for days on end without stopping,” he said.

In humans, the most notable thing about sleep is that it reduces body and brain metabolism while still allowing high level of responsiveness to the environment, such as parent arousing at a baby’s whimper but sleeping through a thunderstorm.

“This Darwinian perspective can explain age-related changes in human sleep patterns as well,” said Siegel.

“We sleep more deeply when we are young, because we have a high metabolic rate that is greatly reduced during sleep, but also because there are people to protect us.

“Our sleep patterns change when we are older, though, because that metabolic rate reduces and we are now the ones doing the alerting and protecting from dangers,” the expert added.

The study appears in journal Nature Reviews Neuroscience. (ANI)

Tone-deaf people lack an important neural pathway

Washington, Aug 19 (ANI): Researchers have found that the nerve fibres that link perception and motor regions of the brain are disconnected in tone-deaf people.

According to experts’ estimates, at least 10 percent of the population may be tone deaf – unable to sing in tune.

The new finding has pinpointed a particular brain circuit that is believed to be absent in these individuals.

“The anomaly suggests that tone-deafness may be a previously undetected neurological syndrome similar to other speech and language disorders, in which connections between perceptual and motor regions are impaired,” said Dr. Psyche Loui, of Beth Israel Deaconess Medical Center and Harvard Medical School, one of the study’s authors.

For the study, the researchers used an MRI-based technique called diffusion tensor imaging to examine connections between the right temporal and frontal lobes.

It is known that this region, a neural “highway” called the arcuate fasciculus, is involved in linking music and language perception with vocal production.

They took brain images of 20 people, half of whom had been identified as tone-deaf through listening tests.

The arcuate fasciculus was smaller in volume, and had a lower fibre count in the tone-deaf individuals.

Particularly, the superior branch of the arcuate fasciculus in the right hemisphere could not be detected in the tone-deaf individuals.

Thus, the researchers speculated that this could mean the branch is missing entirely, or is so abnormally deformed that it appears invisible to even the most advanced neuroimaging methods.

“The findings are clear. They show that the arcuate fasciculus, a structure long-known to join perceptual and motor areas, has reduced connectivity in individuals with tone deafness. Beyond improving our understanding of the anatomical underpinnings of tone-deafness, this study provides new insight into a person’s ability to detect pitch,” said Dr. Nina Kraus, at Northwestern University.

The findings add to previous work by the same researchers demonstrating that tone-deaf people could not consciously hear their own singing, and work by other researchers indicating abnormalities in brain regions that affect sound perception and production.

The study has been published in the latest issue of The Journal of Neuroscience. (ANI)

Younger teens really do care what others think about them

Washington, July 16 (ANI): They might be fond of chanting ‘I don’t care’ slogans every now and then, but deep down inside younger adolescents or “tweens” care a lot about what others think about them, a new study has found.

The study confirmed this using brain-mapping techniques that shed new light on this complex period of social development.

The study, authored by researchers at the University of Oregon and the University of California Los Angeles, has been published in the July/August 2009 issue of the journal Child Development.

Previous research into this area has relied on reports by teenagers themselves. However, the latest study eliminated the potential bias of self-reports by using brain scans to look at the neural systems that support individuals’ perceptions of themselves.

During the brain scans, 12 early adolescents (11- to 13-year-olds) and 12 young adults (22- to 30-year-olds) responded to researchers’ questions about whether short phrases (such as “I am popular”) described them, and whether they believed others (mothers, best friends, classmates) thought these phrases described them, too.

The researchers then examined activity in the brain that occurred when the participants gave their responses.

In comparison to the young adults, the tweens see themselves in ways that may depend more on what they believe others think about their abilities and attributes. And these others-including parents and friends-may have more influence in some areas than in other areas, with moms having more sway over how the tweens view their academic abilities but best friends exerting influence over how they see their social skills, the study found.

“These findings provide a novel form of evidence confirming the sensitivity of adolescents to what they believe others think of them, especially parents and peers,” suggests Jennifer H. Pfeifer, assistant professor of psychology at the University of Oregon and the lead author.

“More importantly, they suggest that being able to see others’ perspectives on oneself may be particularly critical to development in adolescence. As a result, individuals who lack this social cognitive skill (including those with autism spectrum disorders) may face significant obstacles,” she added. (ANI)

Brain scans can tell ‘honest’ person from ‘dishonest’ one even when both tell the truth

Washington, July 14 (ANI): Researching into the cognitive process involved with honesty, Harvard University psychologists have come to the conclusion that truthfulness depends more on absence of temptation than active resistance to temptation.

Assistant Professor Joshua Greene and graduate student Joe Paxton, the duo that led the study, have revealed that they used neuroimaging to look at the brain activity of people given the chance to gain money dishonestly by lying, and found that honest people showed no additional neural activity when telling the truth.

The researchers say that that observation implied that extra cognitive processes were not necessary to choose honesty.

However, the researchers also found that individuals who behaved dishonestly, even when telling the truth, showed additional activity in brain regions that involve control and attention.

“Being honest is not so much a matter of exercising willpower as it is being disposed to behave honestly in a more effortless kind of way. This may not be true for all situations, but it seems to be true for at least this situation,” says Greene.

The researchers say that they carried out the study to test two theories about the nature of honesty – the “Will” theory, in which honesty results from the active resistance of temptation, and the “Grace” theory in which honesty is a product of lack of temptation.

Writing about their findings in the journal Proceedings of the National Academy of Sciences, they have suggested that the “Grace” theory is true, because the honest participants did not show any additional neural activity when telling the truth.

To prompt participants to lie, the researchers created a cover story about the focus of their study. The research was presented as a study of paranormal ability to predict the future.

The researchers asked those participating in the study to predict the outcomes of a series of coin tosses.

The subjects were told that the research team believed predicting the future was more likely when given a monetary incentive, and when the prediction was not shared in advance of the outcome. That gave the participants the opportunity to lie and say that they had correctly predicted the coin toss to win the money.

The subjects’ honesty was assessed based on whether their number of correct responses was statistically feasible.

According to the researchers, the participants who reported improbably high levels of accuracy were classified as dishonest, and those reporting statistically feasible levels of accuracy were classified as honest.

With the aid of fMRI technique, Greene found that the honest individuals displayed little to no additional brain activity when reporting their prediction of the coin toss. However, the dishonest participants’ brains were most active in control-related brain regions when they chose not to lie.

Greene notes that there was an important distinction between the brain activity when the honest participants told the truth, and when the dishonest participants told the truth.

“When the honest people leave money on the table, you don’t see anything special or extra going on in their brains at all. Whereas, when the dishonest people leave money on the table, that’s when you saw the most robust control network activation,” says the researcher.

The researchers hope that their findings may pave the way for a technique to detect lies by looking at someone’s brain activity, but they also concede that a lot more work must be done before this becomes possible. (ANI)

Coimbatore experts bring perfect pictures closer to reality

Washington, July 9 (ANI): Coimbatore-based experts have turned to neural networks to help photographers clean up blur’s noise and distortion in images.

S. Uma of the Coimbatore Institute of Technology and S. Annadurai of the Government College of Technology say that their approach can significantly reduce information loss while reversing blurring caused by lens aberrations and faults and reducing noise that distorts the appearance of an image.

They suggest that distortions in an image due to atmospheric disturbances between camera and distant subjects could be unravelled and a photo taken on a hot, hazy day made acceptable.

The researchers point out that earlier attempts at this kind of inverse filtering of an image rely on the image having a high signal-to-noise (SNR) ratio.

According to them, other approaches require huge amounts of computing power and are generally untenable.

They say that this is especially true in the fledgling field of artificial vision, whether robotic or prosthetic.

However, they add, some success with neural networks has been achieved.

Uma and Annadurai have developed a modified recurrent Hopfield neural network that builds and extends the work of others to allow them to quickly process an image, and reduce distortion, noise and blurring.

When they tested their approach on square grayscale images just 256 pixels across, they were able to reverse severe blurring and noise deliberately added to the original photographic sample to much more acceptable levels in a short time using limited computing resources than was possible with previous neural network approaches or any other inverse filtering techniques.

An analysis of the before and after quality shows that quality is improved by between 39 and 67 per cent using the team’s approach, and results take half the time of other methods that produce lesser improvements.

The success bodes well for image processing, in various fields including vision research, art, homeland security, and science.

A research article describing the new approach has been published in the journal International Journal of Signal and Imaging Systems Engineering. (ANI)

Why minor neuromuscular damage can affect one’s ability to complete everyday tasks

Washington, July 9 (ANI): In what may help understand why minor damage to the neuromuscular system can at times profoundly affect one’s ability to complete everyday tasks, scientists have found that activities combining movement and force tax the brain to capacity, countering a long-held belief that difficulty with dexterous tasks results from the limits of the muscles themselves.

“Our results show how much the mechanics of the body, and a given task, affect what the brain can or can’t do,” said Francisco Valero-Cuevas of the Brain-Body Dynamics Lab at the University of Southern California, who led the research.

“The so-called ‘problem’ of muscle redundancy-having too many muscles and joints to control-may not be the only challenge the brain faces when controlling our bodies. Rather, we seem to have about as many muscles as we need, and not too many, as others have proposed in the past.

“The scientific world and the clinical world have long been arriving at conflicting conclusions, and this work begins to resolve the paradox.

“While neuroscience and biomechanics studies have suggested that muscles and joints are, in theory, redundant and provide numerous alternative solutions to simple tasks, clinicians routinely see people seeking treatment for hand disability resulting from relatively minor conditions such as aging,” added Valero-Cuevas.

The study followed previous experiments that suggested the brain and complex musculature can barely keep up with requirements posed by our anatomy and the mechanics of even ordinary, real-world, finger tasks like rubbing a surface.

The conclusions begin to explain why even minor damage to the neuromuscular system seems to produce real deficits in manipulation.

The research focused on simultaneous force and motion-specifically from fingers either pushing or rubbing a surface-with volunteers conducting the experiment at defined, yet varying, speeds.

Knowing the force-producing properties of muscle, the researchers expected the rubbing motion would show reduced downward force as the speed of motion increased.

Surprisingly, whether rubbing slowly or at a pace 36-times faster, speed had little affect on the downward force the volunteers could produce.

The researchers interpret the results to mean the brain is sufficiently occupied by the physical demands of combining motions and forces, so the muscle properties are not the limiting factors for how much force the fingers can create.

“This begins to explain the clinical reality that when something in the system is damaged, either in the brain or body, we can see losses of function. We are not as ‘redundant’ as we thought,” said Valero-Cuevas.

The research team is conducting additional research to determine what exact neural and anatomical mechanisms are producing these results.

The current study has been published in the Journal of Neuroscience. (ANI)

Soon, face recognition computers that can see through disguises

Washington, July 8 (ANI): Florida Atlantic University engineers in Boca Raton are working on a superior new face recognition technique that can see through disguises.

Lin Huang, from the university’s Department of Engineering, says that every face has special features that define people, yet faces can also be very similar.

The researcher adds that this is what makes computerized face recognition for security and other applications an interesting, but difficult, task.

Face recognition software has been in development for many years, but the main technical limitation is, although the systems are accurate, they require a lot of computer power.

Early face recognition systems simply marked major facial features – eyes, nose mouth – on a photograph, and computed the distances from these features to a common reference point.

In the new study, Huang and colleagues Hanqi Zhuang and Salvatore Morgera have applied a one-dimensional filter to the two-dimensional data from conventional analyses, such as the Gabor method (which is based on neural networks).

This allows them to reduce significantly the amount of computer power required without compromising accuracy.

The team tested the performance of their new algorithm on a standard database of 400 images of 40 subjects. Images are grey scale and just 92 x 112 pixels in size.

They found that their technique was not only faster and worked with low resolution images, such as those produced by standard CCTV cameras, but it also solved the variation problems caused by different light levels and shadows, viewing direction, pose, and facial expressions.

It could even see through certain types of disguises, such as facial hair and glasses.

The findings have been published in International Journal of Intelligent Systems Technologies and Applications. (ANI)

Scientists identify alcohol-binding site in the brain

London, June 29 (ANI): Scientists at the Salk Institute for Biological Studies have a step closer to understanding how alcohol alters the way brain cells work.

The researchers say that they have identified a binding site for alcohol in an ion channel that plays a key role in several brain functions associated with drugs of abuse and seizures.

They believe that their results could lead to the development of novel treatments for alcoholism, drug addiction, and epilepsy.

Ethanol, the alcohol in intoxicating beverages, is known to alter the communication between brain cells.

“There’s been a lot of interest in the field to find out how alcohol acts in the brain,” Nature magazine quoted Dr. Paul A. Slesinger, an associate professor in the Peptide Biology Laboratory at the Salk Institute, as saying.

“One of several views held that ethanol works by interacting directly with ion channel proteins, but there were no studies that visualized the site of association,” added the lead researcher.

He says that his study has shown that alcohols directly interact with a specific nook contained within a channel protein.

According to him, this ion channel plays a key role in several brain functions associated with drugs of abuse and seizures.

In their previous research, Slesinger’s team focused on the neural function of these ion channels, called GIRK channels, which open up during periods of chemical communication between neurons and dampen the signal, creating the equivalent of a short circuit.

“When GIRKs open in response to neurotransmitter activation, potassium ions leak out of the neuron, decreasing neuronal activity,” says UCSD Biology graduate student and first author Prafulla Aryal.

While alcohols have been previously shown to open up GIRK channels, no study ever determined whether this was a direct effect or whether this was the by-product of other molecular changes in the cell.

The researchers say that the identification of the location of a physical alcohol-binding site important for GIRK channel activation could point to new strategies for treating related brain diseases.

They believe that this protein structure may be used to develop a drug that antagonizes the actions of alcohol for the treatment of alcohol dependence.

“(Alternatively) If we could find a novel drug that fits the alcohol-binding site and then activate GIRK channels, this would dampen overall neuronal excitability in the brain and perhaps provide a new tool for treating epilepsy,” says Slesinger.

A research article describing the study has been published in the journal Nature Neuroscience. (ANI)

Ability to imagine oneself in someone else’s shoes ‘tied to empathy’

Washington, June 24 (ANI): The way our brain handles how we move through space-including being able to imagine literally stepping into someone else’s shoes-may be related to how and why we experience empathy toward others, say researchers.

The new study from Vanderbilt University has been published in the online scientific journal PLoS ONE.

Empathy, partly, involves the ability to simulate the internal states of others.

The authors hypothesized that humans’ ability to manipulate, rotate and simulate mental representations of the physical world, including their own bodies, would contribute significantly to their ability to empathize.

“Our language is full of spatial metaphors, particularly when we attempt to explain or understand how other people think or feel. We often talk about putting ourselves in others’ shoes, seeing something from someone else’s point of view, or figuratively looking over someone’s shoulder,” Sohee Park, report co-author and professor of psychology, said.

“Although future work is needed to elucidate the nature of the relationship between empathy, spatial abilities and their potentially overlapping neural underpinnings, this work provides initial evidence that empathy might be, in part, spatially represented,” the expert said.

“We use spatial manipulations of mental representations all the time as we move through the physical world. As a result, we have readily available cognitive resources to deploy in our attempts to understand what we see. This may extend to our understanding of others’ mental states,” Katharine N. Thakkar, a psychology graduate student at Vanderbilt and the report’s lead author, said.

“Separate lines of neuroimaging research have noted involvement of the same brain area, the parietal cortex, during tasks involving visuo-spatial processes and empathy,” she added.

To test their hypothesis that empathy and spatial processes are linked, the researchers designed an experiment in which subjects had to imagine themselves in the position of another person and make a judgment about where this other person’s arm was pointing. The task required the subject to mentally transform their body position to that of the other person.

“We expected that the efficiency with which people could imagine these transformations would be associated with empathy. Because we were interested in linking spatial ability with empathy, we also included a very simple task of spatial attention called the line bisection task.

This test involves looking at a horizontal line and marking the midpoint. Although this task is very simple, it appears to be a powerful way to assess subtle biases in spatial attention,” Thakkar said.

The researchers compared performance on the test with how empathetic the subjects reported themselves to be. They found that higher self-reported empathy was associated with paying more attention to the right side of space.

Boffins also found that in the female subjects only, the more empathetic people rated themselves, the longer they took to imagine themselves in the position of the person on the screen. (ANI)

Ability to imagine oneself in someone else’s shoes ‘tied to empathy’

Washington, June 24 (ANI): The way our brain handles how we move through space-including being able to imagine literally stepping into someone else’s shoes-may be related to how and why we experience empathy toward others, say researchers.

The new study from Vanderbilt University has been published in the online scientific journal PLoS ONE.

Empathy, partly, involves the ability to simulate the internal states of others.

The authors hypothesized that humans’ ability to manipulate, rotate and simulate mental representations of the physical world, including their own bodies, would contribute significantly to their ability to empathize.

“Our language is full of spatial metaphors, particularly when we attempt to explain or understand how other people think or feel. We often talk about putting ourselves in others’ shoes, seeing something from someone else’s point of view, or figuratively looking over someone’s shoulder,” Sohee Park, report co-author and professor of psychology, said.

“Although future work is needed to elucidate the nature of the relationship between empathy, spatial abilities and their potentially overlapping neural underpinnings, this work provides initial evidence that empathy might be, in part, spatially represented,” the expert said.

“We use spatial manipulations of mental representations all the time as we move through the physical world. As a result, we have readily available cognitive resources to deploy in our attempts to understand what we see. This may extend to our understanding of others’ mental states,” Katharine N. Thakkar, a psychology graduate student at Vanderbilt and the report’s lead author, said.

“Separate lines of neuroimaging research have noted involvement of the same brain area, the parietal cortex, during tasks involving visuo-spatial processes and empathy,” she added.

To test their hypothesis that empathy and spatial processes are linked, the researchers designed an experiment in which subjects had to imagine themselves in the position of another person and make a judgment about where this other person’s arm was pointing. The task required the subject to mentally transform their body position to that of the other person.

“We expected that the efficiency with which people could imagine these transformations would be associated with empathy. Because we were interested in linking spatial ability with empathy, we also included a very simple task of spatial attention called the line bisection task.

This test involves looking at a horizontal line and marking the midpoint. Although this task is very simple, it appears to be a powerful way to assess subtle biases in spatial attention,” Thakkar said.

The researchers compared performance on the test with how empathetic the subjects reported themselves to be. They found that higher self-reported empathy was associated with paying more attention to the right side of space.

Boffins also found that in the female subjects only, the more empathetic people rated themselves, the longer they took to imagine themselves in the position of the person on the screen. (ANI)

How brain waves fire in unison while paying attention

Washington, May 29 (ANI): While the neurons in human brains are known to start firing in unison when a person pays attention, scientists have now found the brain centre that controls this neural chorus.

MIT neuroscientists have found that neurons in the prefrontal cortex – the brain’s planning centre – fire in unison and send signals to the visual cortex to do the same, generating high-frequency waves that oscillate between these distant brain regions like a vibrating spring.

The waves, also known as gamma oscillations, have long been associated with cognitive states like attention, learning, and consciousness.

“We are especially interested in gamma oscillations in the prefrontal cortex because it provides top-down influences over other parts of the brain. We know that the prefrontal cortex is affected in people with schizophrenia, ADHD and many other brain disorders, and that gamma oscillations are also altered in these conditions.

Our results suggest that altered neural synchrony in the prefrontal cortex could disrupt communication between this region and other areas of the brain, leading to altered perceptions, thoughts, and emotions,” said senior author Robert Desimone.

The researchers explained this neural synchrony by using the analogy of a crowded party with people talking in different rooms-if individuals raise their voices at random, the noise just becomes louder.

But if a group of individuals in one room chant together in unison, the next room is more likely to hear the message, and if the people in the other room respond in the same way, the two rooms can communicate.

In the study, the researchers looked for patterns of neural synchrony in two “rooms” of the brain associated with attention – the frontal eye field (FEF) within the prefrontal cortex and the V4 region of the visual cortex.

By training two macaque monkeys to watch a monitor displaying multiple objects, and to concentrate on one of the objects, the researchers monitored neural activity in both the above regions of the brain.

They analysed the timing of the neural activity and found that the prefrontal cortex became engaged by attention first, followed by the visual cortex-as if the prefrontal cortex commanded the visual region to snap to attention.

The delay between neural activity in these areas during each wave cycle revealed the speed at which signals travel from one region to the other, which indicated that the two brain regions were talking to one another.

The study has been published in the journal Science. (ANI)

How the brain processes speech

London, May 27 (ANI): A review of human and non-human primate studies suggests that scientists are very close to forming a conclusive theory about the brain processes speech and language.

Dr. Josef Rauschecker of Georgetown University and his co-author Sophie Scott, a neuroscientist at University College, London, say that both human and animal studies have confirmed that speech is processed in the brain along two parallel pathways, each of which run from lower- to higher-functioning neural regions.

The authors describe these pathways as the “what” and “where” streams, which are similar to how the brain processes sight, but are located in different regions.

Both pathways begin with the processing of signals in the auditory cortex, located inside a deep fissure on the side of the brain underneath the temples – the so-called “temporal lobe”.

Information processed by the “what” pathway then flows forward along the outside of the temporal lobe, and the job of that pathway is to recognize complex auditory signals, which include communication sounds and their meaning (semantics).

The “where” pathway is mostly in the parietal lobe, above the temporal lobe, and it processes spatial aspects of a sound – its location and its motion in space – but is also involved in providing feedback during the act of speaking.

Rauschecker says that auditory perception – the processing and interpretation of sound information – is tied to anatomical structures.

“Sound as a whole enters the ear canal and is first broken down into single tone frequencies, then higher-up neurons respond only to more complex sounds, including those used in the recognition of speech, as the neural representation of the sound moves through the various brain regions,” he says.

“In both species, we are using species-specific communication sounds for stimulation, such as speech in humans and rhesus-specific calls in rhesus monkeys. We find that the structure of these communication sounds is similar across species,” he adds.

Rauschecker believes that the findings of this research may ultimately yield some valuable insights into disorders that involve problems in comprehending auditory signals, such as autism and schizophrenia.

“Understanding speech is one of the major problems seen in autism, and a person with schizophrenia hears sounds that are just hallucinations. Eventually, this area of research will lead us to better treatment for these issues,” Rauschecker says.

The study is published in the June issue of Nature Neuroscience. (ANI)

‘Creativity chemical’ in the brain biased towards smarter people

London, May 21 (ANI): High levels of a so-called “creativity chemical” in a certain part of the brain is what boosts creativity in smart people, revealed a study.

People with average intelligence, on the other hand, are less ingenious because of low levels of the same chemical.

N-acetyl-aspartate, which is found in neurons, is apparently linked with neural health and metabolism.

Already, Rex Jung at the University of New Mexico in Albuquerque and his colleagues knew that high levels of NAA in the left parieto-occipital lobe, which coordinates sensory and visual information, were linked with intelligence.

In order to know whether NAA also plays a role in creativity, the researchers recruited 56 men and women aged 18 to 39, and measured the NAA levels in various regions of their brains.

The researchers also tested the volunteers’ general intelligence and, more specifically, their capacity for divergent thinking-a factor in creativity that includes coming up with novel ideas, such as new uses for everyday objects.

On the whole, volunteers’ creativity scores were concurrent with levels of NAA in a brain region called the anterior cingulate gyrus (ACG), which regulates the activity of the frontal cortex – implicated in higher mental functions.

However, while low levels of NAA in the ACG correlated with high creativity in people of average intelligence, the reverse was found to be true in people with IQs of above 120.

Jung predicted that if there is less NAA to regulate frontal cortex activity in “average” brains, they are freer to roam and find new ideas.

However, in highly intelligent people, tighter control over the frontal cortex could apparently enhance creativity.

This could be because they are more likely to come up with new ideas anyway, and the tighter control allows them to “fine-tune” that ability.

“People say you have to let your mind wonder freely to be creative. For people of average intelligence, perhaps it’s true that you need to utilise more areas of your [frontal cortex] for something truly novel and creative to emerge, but in more intelligent folks, there’s something different going on,” New Scientist magazine quoted Jung as saying.

In his opinion, the findings could shed new light on what made the brains of creative geniuses like Einstein tick. (ANI)

Folic acid ‘prevents congenital heart defects’

London, May 15 (ANI): While fortifying grain products with folic acid has been found to be effective in preventing neural tube defects in Canada, scientists have now found that this form of vitamin B also prevents congenital heart defects.

McGill University researchers in Montreal have found in a study that folic acid decreases the incidence of congenital heart defects by more than 6 percent.

Since December 1998, all grain products sold in Canada have been fortified with folic acid with 0.15 mg of folate per 100 g of flour.

With the help of provincial databases, the researchers showed that the rate of congenital heart defects between 1999 and 2005 was 1.47 per 1000 births compared to 1.64 per 1000 births between 1990 and 1999 for a decrease of 6.2 percent per year after 1999.

Despite the success of this initiative, prevention efforts are still necessary to encourage future mothers to take folic acid supplements.

“The level of fortification was established to avoid negative side effects in the general population,” said Raluca Ionescu-Ittu, a PhD candidate on the team.

“However, this level is not quite sufficient for women planning a pregnancy, who should start taking folic acid supplements at least three months before becoming pregnant,” Ionescu-Ittu added.

The study has been published in the British Medical Journal. (ANI)

How the brain handles words

Washington, Apr 30 (ANI): How the brain gives meaning to letters on a page has been a mystery for scientists. Now, a new study has tried to solve the puzzle.

Neuroscientists at Georgetown University Medical Center have found that an area known to be important for reading in the left visual cortex contains neurons that are specialized to process written words as whole word units.

Although some theories of reading as well as neuropsychological and experimental data have argued for the existence of a neural representation for whole written real words (an “orthographic lexicon”), evidence for this has been elusive.

“Reading relies on neural representations that are experience dependent,” says senior author Maximilian Riesenhuber, PhD, of the GUMC Laboratory for Computational Cognitive Neuroscience.

“Evolution did not provide each of us with a little dictionary in our heads,” the expert added.

Because the findings, published in the April 30 issue of Neuron, shed light on how written words are processed in the brain, they also provide clues as to how reading disorders such as dyslexia could arise, Riesenhuber says.

“Previous studies have shown that this brain area is affected in reading disorders such as dyslexia, but it is unclear what the mechanisms involved are. Our data suggest that looking at the neuronal selectivity in this area might provide new insight. For instance, we would expect reading difficulties if neurons never become well tuned to words, making reading a slow, arduous process, just like it would be if reading all nonwords,” the expert added.

The GUMC researchers – Riesenhuber, first author Laurie S. Glezer, MA, and Xiong Jiang, PhD – set up a series of experiments with the participation of volunteers. They showed the participants pairings of words, and used functional Magnetic Resonance Imaging (fMRI) to measure brain blood flow in an area in the left visual cortex called the “visual word form area” while the participants performed a reading task.

Most other studies using fMRI to examine the “visual word form area” have used the averaged neuronal response in which many word stimuli are presented and the change in activity is measured, but this approach does not tease out the response neurons have to individual words, Riesenhuber says. However, by using the technique of fMRI rapid adaptation, in which the stimuli are shown in pairs, it is possible to measure the selectivity of neurons for individual words.

In their experiments, the researchers looked at the response between two visually similar normal words that shared all letters but one (i.e. ‘boat’ and ‘coat’) and found that the neural response to this condition “looked just like when participants saw two words that shared no letters, for example ‘coat’ and ‘fish’,” says Glezer.

“This shows that the neurons in this area of the brain are very selective for individual words. Even though the two words shared all letters but one, there is no overlap in the neural representation, just like when the two words are completely different,” the expert said.

The researchers then looked at the brain’s response to sets of nonwords in which the stimuli look like real words but have never been seen before (i.e. tarm). They found that the response to nonwords was not selective, with similar nonwords appearing to have overlapping neural representations. (ANI)

Secrets of unconditional love unraveled

London, Apr 12 (ANI): The reason why you immeasurably care for a person without any thought of reward is one of science’s biggest mystery. Now, researchers at Montreal University claim that they have unravelled the secret behind unconditional love.

The research team, led by Professor Mario Beauregard, of Montreal University’s centre for research into neurophysiology and cognition, found that the emotion emerges from a complex interplay between seven separate areas of the brain.

Such brain activity has only limited overlap with the cerebral impulses seen in romantic or sexual love, suggesting it should be seen as an entirely separate emotion.

“Unconditional love, extended to others without exception, is considered to be one of the highest expressions of spirituality. However, nothing has been known regarding its neural underpinnings until now,” The Times quoted Mario, as saying.
To reach the conclusion, the volunteers were recruited on the basis that they had a proven ability to feel strong unconditional love: low-paid assistants looking after people with learning difficulties.

In the study, Mario asked them to evoke feelings of unconditional love and hold them in their minds while they had a magnetic resonance imaging (MRI) scan.

Of the seven brain areas that became active, three were similar to those of romantic love. The others were different, suggesting a separate kind of love.

The findings showed that some of the areas activated when experiencing unconditional love were also involved in releasing dopamine – a chemical deeply involved in sensing pleasure, with rising levels strongly linked to feelings of reward and even euphoria.

In a research paper in an academic journal, Mario said: “The rewarding nature of unconditional love facilitates the creation of strong emotional links. Such robust bonds may critically contribute to the survival of the human species.” (ANI)