Weekly Neuroscience Update

May 14, 2017May 14, 2017Leave a comment

A new generation of prosthetic limbs which will allow the wearer to reach for objects automatically, without thinking – just like a real hand – are to be trialled for the first time.

Researchers have discovered both the structure of specific brain areas and memory are linked to genetic activity that also play important roles in immune system function.

Understanding the structure of our brain is as important as understanding its size when it comes to evolution, a new report suggests.

Scientists have published ground-breaking scans of newborn babies’ brains which researchers from all over the world can download and use to study how the human brain develops.

A new study reports that contrary behaviour of blood vessels in the retrotrapezoid nucleus help keep us breathing.

Researchers have developed a non-invasive means to measure whether infants are in pain, which could prevent babies from undergoing excessive discomfort during medical treatments.

A landmark study has identified the first genetic locus for anorexia nervosa and has revealed that there may also be metabolic underpinnings to this potentially deadly illness.

Finally this week, researchers have identified how two distinct areas of the developing brain communicate and report REM sleep is key to this communication.

How Your Brain Sees Things You Don’t

March 3, 2014March 3, 20141 Comment

What do you see in this image? (Credit: Jay Sanguinetti)

A new study indicates that our brains perceive objects in everyday life that we may not be consciously aware of.

The finding by University of Arizona doctoral student Jay Sanguinetti challenges currently accepted models, in place for a century, about how the brain processes visual information.

Sanguinetti showed study participants a series of black silhouettes, some of which contained meaningful, real-world objects hidden in the white spaces on the outsides. He monitored subjects’ brainwaves with an electroencephalogram, or EEG, while they viewed the objects.

Study participants’ brainwaves indicated that even if a person never consciously recognized the shapes on the outside of the image, their brains still processed those shapes to the level of understanding their meaning.

A brainwave that indicates recognition of an object

“There’s a brain signature for meaningful processing,” Sanguinetti said. A peak in the averaged brainwaves called N400 indicates that the brain has recognized an object and associated it with a particular meaning.

“It happens about 400 milliseconds after the image is shown, less than a half a second,” said Peterson. “As one looks at brainwaves, they’re undulating above a baseline axis and below that axis.

The negative ones below the axis are called N and positive ones above the axis are called P, so N400 means it’s a negative waveform that happens approximately 400 milliseconds after the image is shown.”

The presence of the N400 negative peak indicates that subjects’ brains recognize the meaning of the shapes on the outside of the figure.

“The participants in our experiments [in some cases] don’t see those shapes on the outside; nonetheless, the brain signature tells us that they have processed the meaning of those shapes,” said said Sanguinetti adviser Mary Peterson, a professor of psychology and director of the UA’s Cognitive Science Program.

“But the brain rejects them as interpretations, and if it rejects the shapes from conscious perception, then you won’t have any awareness of them.”

“We also have novel silhouettes as experimental controls,” Sanguinetti said. “These are novel black shapes in the middle and nothing meaningful on the outside.”

The N400 waveform does not appear on the EEG of subjects when they are seeing these truly novel silhouettes, without images of any real-world objects, indicating that the brain does not recognize a meaningful object in the image.

“This is huge,” Peterson said. “We have neural evidence that the brain is processing the shape and its meaning of the hidden images in the silhouettes we showed to participants in our study.”

So why does the brain process images that are not perceived?

The finding leads to the question: why would the brain process the meaning of a shape when a person is ultimately not going to perceive it?

“Many, many theorists assume that because it takes a lot of energy for brain processing, that the brain is only going to spend time processing what you’re ultimately going to perceive,” said Peterson.

“But in fact the brain is deciding what you’re going to perceive, and it’s processing all of the information and then it’s determining what’s the best interpretation.

“This is a window into what the brain is doing all the time. It’s always sifting through a variety of possibilities and finding the best interpretation for what’s out there. And the best interpretation may vary with the situation.”

Our brains may have evolved to sift through the barrage of visual input in our eyes and identify those things that are most important for us to consciously perceive, such as a threat or resources such as food, Peterson suggested.

Finding where the processing of meaning occurs

In the future, Peterson and Sanguinetti plan to look for the specific regions in the brain where the processing of meaning occurs to understand where and how this meaning is processed,” said Peterson.

Images were shown to Sanguinetti’s study participants for only 170 milliseconds, yet their brains were able to complete the complex processes necessary to interpret the meaning of the hidden objects.

“There are a lot of processes that happen in the brain to help us interpret all the complexity that hits our eyeballs,” Sanguinetti said. “The brain is able to process and interpret this information very quickly.”

How this relates to the real world

Sanguinetti’s study indicates that in our everyday life, as we walk down the street, for example, our brains may recognize many meaningful objects in the visual scene, but ultimately we are aware of only a handful of those objects, said Sanguinetti.

The brain is working to provide us with the best, most useful possible interpretation of the visual world — an interpretation that does not necessarily include all the information in the visual input.

“The findings in the research also show that our brains are processing potential objects in a visual scene to much higher levels of processing than once thought,” he explained to KurzweilAI. “Our models assume that potential objects compete for visual representation. The one that wins the competition is perceived as the object, the loser is perceived as the shapeless background.

“Since we’ve shown that shapeless backgrounds are processed to the level of semantics (meaning), there might be a way to bias this processing such that hidden objects in a scene might be perceived, by tweaking the image in ways to enunciate certain objects over others. This could be useful in many applications like radiology, product design, and even art.”

Notes:

Silhouette Image: Sanguinetti showed study participants images of what appeared to be an abstract black object. Sometimes, however, there were real-world objects hidden at the borders of the black silhouette. In this image, the outlines of two seahorses can be seen in the white spaces surrounding the black object.

Original source of article http://www.kurzweilai.net/does-your-brain-see-things-you-dont

REFERENCES:

Joseph L. Sanguinetti, John J. B. Allen, and Mary A. Peterson, The Ground Side of an Object: Perceived as Shapeless yet Processed for Semantics, Psychological Science, 2013, doi: 10.1177/0956797613502814

Speech processing requires both sides of our brain

February 3, 2014Leave a comment

A new study by Cogan et al proposes that speech processes occur on both sides of the brain and are distinct from language, which occurs on one side, typically on the left. This suggests a revision to the standard model of how speech is linked to language with some processes going through a “bilateral sensory-motor interface”. Credit: Greg Cogan and Bijan Pesaran

A new study has found that we use both sides of our brain for speech, a finding that alters previous conceptions about neurological activity. The results, which appear in the journal Nature, also offer insights into addressing speech-related inhibitions caused by stroke or injury and lay the groundwork for better rehabilitation methods.

The study’s senior author, Bijan Pesaran, an associate professor in New York University’s Center for Neural Science, said:

Our findings upend what has been universally accepted in the scientific community—that we use only one side of our brains for speech. With this greater understanding of the speech process, we can retool rehabilitation methods in ways that isolate speech recovery and that don’t involve language.

Weekly Neuroscience Update

November 9, 2012November 9, 2012

Scientists have located a specific set of neurons that indicate how time passes, confirming that the brain plays an essential role in how we experience the passage of time.

Neuroscientists have found that by training on attention tests, people young and old can improve brain performance and multitasking skills.

A gene that is associated with regeneration of injured nerve cells has been identified by scientists at Penn State University and Duke University.

When given early treatment, children with autism spectrum disorders (ASD) made significant improvements in behavior, communication, and most strikingly, brain function, Yale School of Medicine researchers report in a new study.

Researchers have found some of the earliest signs of Alzheimer’s disease, more than two decades before the first symptoms usually appear.

Weekly Neuroscience Update

September 28, 2012September 28, 2012

Newly formed emotional memories can be erased from the human brain. This is shown by researchers from Uppsala University in a new study now being published by the academic journal Science. The findings may represent a breakthrough in research on memory and fear.

A growing body of research shows that children who suffer severe neglect and social isolation have cognitive and social impairments as adults. A study from Boston Children’s Hospital shows, for the first time, how these functional impairments arise: Social isolation during early life prevents the cells that make up the brain’s white matter from maturing and producing the right amount of myelin, the fatty “insulation” on nerve fibers that helps them transmit long-distance messages within the brain.

People with psychopathic tendencies have an impaired sense of smell, which points to inefficient processing in the front part of the brain [orbitofrontal cortex]. These findings by Mehmet Mahmut and Richard Stevenson, from Macquarie University in Australia, are published online in Springer’s journal Chemosensory Perception.

According to new research of MRI scans of children’s appetite and pleasure centers in their brains, the logos of such fast-food giants as McDonald’s, Pizza Hut, and Burger King causes those areas to “light up”.

New signs of future Alzheimer’s disease have been identified by researchers at Lund University and Skane University in Sweden. Dr. Peder Buchhave and his team explain that disease-modifying treatments are more beneficial if started early, so it is essential identify Alzheimer’s disease patients as quickly as possible.

A new study from MIT neuroscientists sheds light on a neural circuit that makes us likelier to remember what we’re seeing when our brains are in a more attentive state.

Weekly Neuroscience Update

July 13, 2012

UC Santa Barbara scientists turned to the simple sponge to find clues about the evolution of the complex nervous system and found that, but for a mechanism that coordinates the expression of genes that lead to the formation of neural synapses, sponges and the rest of the animal world may not be so distant after all.

Scientists have discovered a mechanism which stops the process of forgetting anxiety after a stress event. In experiments they showed that feelings of anxiety don’t subside if too little dynorphin is released into the brain. The results can help open up new paths in the treatment of trauma patients. The study has been published in the current edition of the Journal of Neuroscience.

The biological role of a gene variant implicated in multiple sclerosis (MS) has been determined by researchers at Oxford University. The finding explains why MS patients do badly on a set of drugs used successfully in other autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease – something that has been a puzzle for over 10 years.

A clinical trial of an Alzheimer’s disease treatment developed at MIT has found that the nutrient cocktail can improve memory in patients with early Alzheimer’s. The results confirm and expand the findings of an earlier trial of the nutritional supplement, which is designed to promote new connections between brain cells.

An international consortium, has taken cells from Huntington’s Disease patients and generated human brain cells that develop aspects of the disease in the laboratory. The cells and the new technology will speed up research into understanding the disease and also accelerate drug discovery programs aimed at treating this terminal, genetic disorder.

Stem cells that come from a specific part of the developing brain help fuel the growth of brain tumors caused by an inherited condition, researchers at Washington University School of Medicine in St. Louis report.

Findings from the first study directly examining gamma-aminobutyric acid (GABA) concentrations in the brains of children with ADHD were published last week in the Archives of General Psychiatry. In this new article researchers report finding significantly lower concentrations of GABA in the cerebral cortexes of children diagnosed with ADHD, compared with typically developing children. GABA is the brain’s main inhibitory neurotransmitter. The differences were detected in the region of the brain that controls voluntary movement.

People who are born deaf process the sense of touch differently than people who are born with normal hearing, according to research funded by the National Institutes of Health. The finding reveals how the early loss of a sense— in this case hearing—affects brain development. It adds to a growing list of discoveries that confirm the impact of experiences and outside influences in molding the developing brain. The study is published in the July 11 online issue of The Journal of Neuroscience.

Neuronal abnormalities in the brains of children with obstructive sleep apnea are reversible with treatment, a prospective study has shown.

Although many areas of the human brain are devoted to social tasks like detecting another person nearby, a new study has found that one small region carries information only for decisions during social interactions. Specifically, the area is active when we encounter a worthy opponent and decide whether to deceive them. A brain imaging study conducted by researchers at the Duke Center for Interdisciplinary Decision Science (D-CIDES) put human subjects through a functional MRI brain scan while playing a simplified game of poker against a computer and human opponents. Using computer algorithms to sort out what amount of information each area of the brain was processing, the team found only one brain region — the temporal-parietal junction, or TPJ — carried information that was unique to decisions against the human opponent.

Weekly Neuroscience Update

July 6, 2012July 6, 2012

Scientists have discovered that older honey bees effectively reverse brain aging when they take on nest responsibilities typically handled by much younger bees. While current research on human age-related dementia focuses on potential new drug treatments, researchers say these findings suggest that social interventions may be used to slow or treat age-related dementia.

Scientists tracked brain activity in 40 people with new back injuries and found a pattern of activity that could predict — with 85% accuracy — which patients were destined to develop chronic pain and which weren’t.

Research published in Neuron reveals that underdevelopment of an impulse control center in the brain is, at least in part, the reason children who fully understand the concept of fairness fail to act accordingly.

Researchers are developing a robotic system with ability to predict the specific action or movement that they should perform when handling an object.

The widely used diabetes drug metformin comes with a rather unexpected and side effect: it encourages the growth of new neurons in the brain.

Researchers have long been interested in discovering the ways that human brains represent thoughts through a complex interplay of electrical signals. Recent improvements in brain recording and statistical methods have given researchers unprecedented insight into the physical processes under-lying thoughts. For example, researchers have begun to show that it is possible to use brain recordings to reconstruct aspects of an image or movie clip someone is viewing, a sound someone is hearing or even the text someone is reading.

A new brain scanner has been developed to help people who are completely paralysed speak by enabling them to spell words using their thoughts.

Volunteers Wanted For Depression Research

July 4, 2012

The Department of Psychiatry, St. Patrick’s University Hospital, Dublin, is looking for volunteers for a research study investigating differences in memory function between people who have experienced depression at some point in their lives and those who have not. It involves completing some straightforward depression assessments and memory tasks. The aim of this study is to examine individuals’ memory function after an episode of major depression and compare it to people who have never experienced depression.

What does it involve?

Completing some depression questionnaires and memory tasks on a one-off basis. These assessments will investigate the participants’ depression history and their cognitive functioning in areas such as memory, attention, and language. The assessments are straightforward and should take no more than 2 hours to complete.

Am I eligible to take part?

If you have recently recovered from an episode of major depression, have experienced depression at any point in your life, or have no history of depression but are simply interested in the areas of depression and memory, you are eligible to participate in this study.

How do I take part?

All enquiries are treated wholly confidentially, as is any information collected as part of this research. If you would like to volunteer two hours of your time, please contact our research team through our website www.depression-research.ie, by email at volunteer@depression-research.ie, or telephone (01) 2493537.

Your Weekly Neuroscience Update

June 8, 2012June 8, 2012

Drinking three cups of coffee daily could help keep Alzheimer’s disease at bay, according to the results of a new study.

People who frequently use tanning beds experience changes in brain activity during their tanning sessions that mimic the patterns of drug addiction, new research shows.

A research team at Aalto University and Turku PET Centre has revealed how experiencing strong emotions synchronizes brain activity across individuals.

A new study has begun to unravel one long-observed enigma in major depressive disorder: why, for most patients, it continues to come back, even after it seems to have been cured or gone away on its own.

A recent placebo-controlled study showed evidence of trans-cranial bright light’s effect to brain functions when administered through the ear. Bright light stimulation was found to increase activity in brain areas related to processing of visual sensory information and tactile stimuli. The findings are the first ever published scientific article about functional modulation of the brain with bright light delivered to the brain through the ears. Researchers from the Max Planck Florida Institute (MPFI) and New York’s Columbia University have discovered that the rewiring involves fibers that provide primary input to the cerebral cortex, which is involved in cognition, sensory perception and motor control.

When people close their eyes, they can form mental images of things that exist only in their minds. Neuroscientists studying this phenomenon at medical schools in the Texas Medical Center believe that there may be a way to use these mental images to help some of the estimated 39 million people worldwide who are blind.

A Canadian doctor has found a promising way to detect concussions using a simple blood test that can tell within the first hour after a blow to the head how severe the injury may be.

Know Your Neurons

June 4, 2012

Different Types of Neurons A. Purkinje cell B. Granule cell C. Motor neuron D. Tripolar neuron E. Pyramidal Cell F. Chandelier cell G. Spindle neuron H. Stellate cell (Credit: Ferris Jabr; based on reconstructions and drawings by Cajal)

The Know Your Neurons series on the Scientific American website features some great information on the discovery and naming of neurons, alongside some terrific historical images.