1. New brain mapping technique highlights relationship between connectivity and IQ

    January 17, 2018 by Ashley

    From the University of Cambridge press release:

    A new and relatively simple technique for mapping the wiring of the brain has shown a correlation between how well connected an individual’s brain regions are and their intelligence, say researchers at the University of Cambridge.

    In recent years, there has been a concerted effort among scientists to map the connections in the brain — the so-called ‘connectome‘ — and to understand how this relates to human behaviours, such as intelligence and mental health disorders.

    Now, in research published in the journal Neuron, an international team led by scientists at the University of Cambridge and the National Institutes of Health (NIH), USA, has shown that it is possible to build up a map of the connectome by analysing conventional brain scans taken using a magnetic resonance imaging (MRI) scanner.

    The team compared the brains of 296 typically-developing adolescent volunteers. Their results were then validated in a cohort of a further 124 volunteers. The team used a conventional 3T MRI scanner, where 3T represents the strength of the magnetic field; however, Cambridge has recently installed a much more powerful Siemens 7T Terra MRI scanner, which should allow this technique to give an even more precise mapping of the human brain.

    A typical MRI scan will provide a single image of the brain, from which it is possible to calculate multiple structural features of the brain. This means that every region of the brain can be described using as many as ten different characteristics. The researchers showed that if two regions have similar profiles, then they are described as having ‘morphometric similarity’ and it can be assumed that they are a connected network. They verified this assumption using publically-available MRI data on a cohort of 31 juvenile rhesus macaque monkeys to compare to ‘gold-standard’ connectivity estimates in that species.

    Using these morphometric similarity networks (MSNs), the researchers were able to build up a map showing how well connected the ‘hubs’ — the major connection points between different regions of the brain network — were. They found a link between the connectivity in the MSNs in brain regions linked to higher order functions — such as problem solving and language — and intelligence.

    “We saw a clear link between the ‘hubbiness’ of higher-order brain regions — in other words, how densely connected they were to the rest of the network — and an individual’s IQ,” explains PhD candidate Jakob Seidlitz at the University of Cambridge and NIH. “This makes sense if you think of the hubs as enabling the flow of information around the brain — the stronger the connections, the better the brain is at processing information.”

    While IQ varied across the participants, the MSNs accounted for around 40% of this variation — it is possible that higher-resolution multi-modal data provided by a 7T scanner may be able to account for an even greater proportion of the individual variation, says the researchers.

    “What this doesn’t tell us, though, is where exactly this variation comes from,” adds Seidlitz. “What makes some brains more connected than others — is it down to their genetics or their educational upbringing, for example? And how do these connections strengthen or weaken across development?”

    “This could take us closer to being able to get an idea of intelligence from brain scans, rather than having to rely on IQ tests,” says Professor Ed Bullmore, Head of Psychiatry at Cambridge. “Our new mapping technique could also help us understand how the symptoms of mental health disorders such as anxiety and depression or even schizophrenia arise from differences in connectivity within the brain.”

     


  2. Danger changes how rat brain stores information

    January 15, 2018 by Ashley

    From the Society for Neuroscience press release:

    The male rat brain changes how it stores information depending on whether the environment in which it learns is safe or dangerous, according to new research published in eNeuro.

    Emotionally charged information, such as danger, is processed by the amygdala. Although this brain region is typically not involved in the acquisition of harmless information, Nathan Holmes and colleagues previously showed that the amygdala is sensitive to the context in which rats learn an association between two neutral stimuli, a sound and a light. This learning was revealed when one stimulus was subsequently paired with a mild foot shock: rats exhibited freezing when finally tested with both stimuli, indicating that they had associated the stimulus that was not paired with a shock with the stimulus that was.

    Using a similar approach in this study, the researchers demonstrate that the perirhinal cortex — a region in the medial temporal lobe — was involved in consolidating the association between the two stimuli when the rats were trained in a safe and familiar environment. On the other hand, the basolateral complex of the amygdala was involved in consolidating the same association when it was learned in a context where the rats had been previously shocked, thereby rendering the environment dangerous at the time of learning. This same region was also required for consolidation when the environment was safe at the time of learning, but rendered dangerous immediately after training.


  3. Study suggests mirror neuron activity predicts people’s decision-making in moral dilemmas

    January 13, 2018 by Ashley

    From the University of California – Los Angeles press release:

    It is wartime. You and your fellow refugees are hiding from enemy soldiers, when a baby begins to cry. You cover her mouth to block the sound. If you remove your hand, her crying will draw the attention of the soldiers, who will kill everyone. If you smother the child, you’ll save yourself and the others.

    If you were in that situation, which was dramatized in the final episode of the ’70s and ’80s TV series “M.A.S.H.,” what would you do?

    The results of a new UCLA study suggest that scientists could make a good guess based on how the brain responds when people watch someone else experience pain. The study found that those responses predict whether people will be inclined to avoid causing harm to others when facing moral dilemmas.

    “The findings give us a glimpse into what is the nature of morality,” said Dr. Marco Iacoboni, director of the Neuromodulation Lab at UCLA’s Ahmanson-Lovelace Brain Mapping Center and the study’s senior author. “This is a foundational question to understand ourselves, and to understand how the brain shapes our own nature.”

    In the study, which was published in Frontiers in Integrative Neuroscience, Iacoboni and colleagues analyzed mirror neurons, brain cells that respond equally when someone performs an action or simply watches someone else perform the same action. Mirror neurons play a vital role in how people learn through mimicry and feel empathy for others.

    When you wince while seeing someone experience pain — a phenomenon called “neural resonance” — mirror neurons are responsible.

    Iacoboni wondered if neural resonance might play a role in how people navigate complicated problems that require both conscious deliberation and consideration of another’s feelings.

    To find out, researchers showed 19 volunteers two videos: one of a hypodermic needle piercing a hand, and another of a hand being gently touched by a cotton swab. During both, the scientists used a functional MRI machine to measure activity in the volunteers’ brains.

    Researchers later asked the participants how they would behave in a variety of moral dilemmas, including the scenario involving the crying baby during wartime, the prospect of torturing another person to prevent a bomb from killing several other people and whether to harm research animals in order to cure AIDS.

    Participants also responded to scenarios in which causing harm would make the world worse — inflicting harm on another person in order to avoid two weeks of hard labor, for example — to gauge their willingness to cause harm for moral reasons and for less-noble motives.

    Iacoboni and his colleagues hypothesized that people who had greater neural resonance than the other participants while watching the hand-piercing video would also be less likely to choose to silence the baby in the hypothetical dilemma, and that proved to be true. Indeed, people with stronger activity in the inferior frontal cortex, a part of the brain essential for empathy and imitation, were less willing to cause direct harm, such as silencing the baby.

    But the researchers found no correlation between people’s brain activity and their willingness to hypothetically harm one person in the interest of the greater good — such as silencing the baby to save more lives. Those decisions are thought to stem from more cognitive, deliberative processes.

    The study confirms that genuine concern for others’ pain plays a causal role in moral dilemma judgments, Iacoboni said. In other words, a person’s refusal to silence the baby is due to concern for the baby, not just the person’s own discomfort in taking that action.

    Iacoboni’s next project will explore whether a person’s decision-making in moral dilemmas can be influenced by decreasing or enhancing activity in the areas of the brain that were targeted in the current study.

    “It would be fascinating to see if we can use brain stimulation to change complex moral decisions through impacting the amount of concern people experience for others’ pain,” Iacoboni said. “It could provide a new method for increasing concern for others’ well-being.”

    The research could point to a way to help people with mental disorders such as schizophrenia that make interpersonal communication difficult, Iacoboni said.

    The study’s first author is Leo Moore, a UCLA postdoctoral scholar in psychiatry and biobehavioral sciences. Paul Conway of Florida State University and the University of Cologne, Germany, is the paper’s other co-author.

    The study was supported by the National Institute of Mental Health, the Brain Mapping Medical Research Organization, the Brain Mapping Support Foundation, the Pierson-Lovelace Foundation, the Ahmanson Foundation, the William M. and Linda R. Dietel Philanthropic Fund at the Northern Piedmont Community Foundation, the Tamkin Foundation, the Jennifer Jones-Simon Foundation, the Capital Group Companies Charitable Foundation, the Robson family, and the Northstar Fund.


  4. Study suggests adolescent brain makes learning easier

    January 9, 2018 by Ashley

    From the Leiden Universiteit press release:

    The brains of adolescents react more responsively to receiving rewards. This can lead to risky behaviour, but, according to Leiden University research, it also has a positive function: it makes learning easier. This work has been published in Nature Communications.

    Alcohol abuse, reckless behaviour and poor choice in friends: all these are inextricably linked to puberty and adolescence. In the late teens, young people test their limits, and in many cases, push beyond their limits. This is due in part to increased activity in the corpus striatum, a small area deeply hidden away inside the brain. According to previous research, that part of the brain in young people is more responsive to receiving rewards.

    Sensitive

    Leiden University scientists are now able to show that this increased activity in the corpus striatum does not have only negative consequences. ‘The adolescent brain is very sensitive to feedback,’ says Sabine Peters, assistant professor of developmental and educational psychology and lead author of the article. ‘That makes adolescence the ideal time to acquire and retain new information.’

    Peters used a large data set for her research with MRI scans. Over a period of five years, no fewer than 736 brain scans were made of a total of 300 subjects between the ages of 8 and 29. According to Peters, the data set is about ten times larger than that of most comparable studies. In the MRI scanner, participants had to solve a memory game. During that game, the researchers gave feedback on the participants’ performance.

    Instructional feedback

    ‘It showed that adolescents responded keenly to educational feedback’, says Peters. ‘If the adolescent received useful feedback, then you saw the corpus striatum being activated. This was not the case with less pertinent feedback, for example, if the test person already knew the answer. The stronger your brain recognises that difference, the better the performance in the learning task. Brain activation could even predict learning performance two years into the future.’

    It has been known for some time that adolescent brains become more ‘successful’ when they receive the same reward as small children or adults. For example, it has already been proven that the use of drugs and/or alcohol in the teenage years is linked to powerful activation in the brain’s reward system. Peters: ‘It explains why adolescents and young adults go on a voyage of discovery, with all the positive and negative consequences that entails. You see the same behaviour in many animal species, including rats and mice.’


  5. Blueberry vinegar improves memory in mice with amnesia

    by Ashley

    From the American Chemical Society press release:

    Dementia affects millions of people worldwide, robbing them of their ability to think, remember and live as they once did. In the search for new ways to fight cognitive decline, scientists report in ACS’ Journal of Agricultural and Food Chemistry that blueberry vinegar might offer some help. They found that the fermented product could restore cognitive function in mice.

    Recent studies have shown that the brains of people with Alzheimer’s disease, the most common form of dementia, have lower levels of the signaling compound acetylcholine and its receptors. Research has also demonstrated that blocking acetylcholine receptors disrupts learning and memory. Drugs to stop the breakdown of acetylcholine have been developed to fight dementia, but they often don’t last long in the body and can be toxic to the liver. Natural extracts could be a safer treatment option, and some animal studies suggest that these extracts can improve cognition. Additionally, fermentation can boost the bioactivity of some natural products. So Beong-Ou Lim and colleagues wanted to test whether vinegar made from blueberries, which are packed with a wide range of active compounds, might help prevent cognitive decline.

    To carry out their experiment, the researchers administered blueberry vinegar to mice with induced amnesia. Measurements of molecules in their brains showed that the vinegar reduced the breakdown of acetylcholine and boosted levels of brain-derived neurotrophic factor, a protein associated with maintaining and creating healthy neurons. To test how the treatment affected cognition, the researchers analyzed the animals’ performance in mazes and an avoidance test, in which the mice would receive a low-intensity shock in one of two chambers. The treated rodents showed improved performance in both of these tests, suggesting that the fermented product improved short-term memory. Thus, although further testing is needed, the researchers say that blueberry vinegar could potentially be a promising food to help treat amnesia and cognitive decline related to aging.


  6. Study examines how odours are turned into long-term memories

    January 8, 2018 by Ashley

    From the Ruhr-Universität-Bochum press release:

    The neuroscientists Dr Christina Strauch and Prof Dr Denise Manahan-Vaughan from the Ruhr-Universität Bochum have investigated which brain area is responsible for storing odours as long-term memories. Some odours can trigger memories of experiences from years back. The current study shows that the piriform cortex, a part of the olfactory brain, is involved in the process of saving those memories; the mechanism, however, only works in interaction with other brain areas. The findings have been published in the journal Cerebral Cortex.

    “It is known that the piriform cortex is able to temporarily store olfactory memories. We wanted to know, if that applies to long-term memories as well,” says Christina Strauch.

    Artificial sensation through stimulation

    Synaptic plasticity is responsible for the storing of memories in the memory structures of the brain: During that process the communication between neurons is altered by means of a process called synaptic plasticity, so that a memory is created. Strauch and Manahan-Vaughan examined if the piriform cortex of rats is capable of expressing synaptic plasticity and if this change lasts for more than four hours; indicating that long-term memory may have been established.

    The scientists used electrical impulses in the brain to emulate processes that trigger the encoding of an olfactory sensation as a memory. They used different stimulation protocols which varied in the frequency and intensity of the pulses. It is known that these protocols can induce long-term effects in another brain area that is responsible for long term memories: the hippocampus. Strikingly, the same protocols did not induce long-term information storage in the form of synaptic plasticity in the piriform cortex.

    Signal from a higher brain area needed

    The scientists wondered whether the piriform cortex needs to be instructed to create a long-term memory. They then stimulated a higher brain area called the orbitofrontal cortex, which is responsible for the discrimination of sensory experiences. This time the stimulation of the brain area generated the desired change in the piriform cortex. “Our study shows that the piriform cortex is indeed able to serve as an archive for long-term memories. But it needs instruction from the orbitofrontal cortex — a higher brain area — indicating that an event is to be stored as a long-term memory,” says Strauch.


  7. Study looks at how the unconscious mind picks out faces in a crowd

    January 7, 2018 by Ashley

    From the Hebrew University of Jerusalem press release:

    Imagine you’re walking down a busy street like Times Square in New York. There are tons of people around. As you make your way through the crowd, your brain notices several faces but ignores the rest. Why is that? What are the processes that determine which faces our brain “chooses” to see and those it allows to fade into the background?

    Today, a new study published in the journal Nature Human Behavior by Professor Ran Hassin, the Hebrew University of Jerusalem (HUJI)’s James Marshall Chair in Social Psychology and member of its Federmann Center for the Study of Rationality, along with HUJI graduate student Yaniv Abir and colleagues Professor Alexander Todorov of Princeton University and Professor Ron Dotsch, formerly of Utrecht University in the Netherlands, describes how the unconscious mind processes human faces and the two types of faces it chooses to consciously see, namely: those associated with dominance and threat and, to a lesser degree, with trustworthiness.

    Hassin and his research team conducted six experiments with 174 participants. In these experiments, researchers exposed participants to 300 sets of rapidly-changing images. In one eye, participants were exposed to images of human faces, and in the other eye they were exposed to geometric shapes. The participants were then asked to press a computer key as soon as they saw a human face.

    With the onslaught of stimuli — images and rapid flashing — it took the brain a few seconds to understand that it was seeing a face and then to “transfer” these images to the conscious brain for processing. The researchers observed that the facial dimensions that were most quickly registered by participants were ones that indicated power and dominance.

    “Walking around the world our unconscious minds are faced with a tremendous task: decide which stimuli ‘deserve’ conscious noticing and which do not,” explained Hassin. “The mental algorithm we discovered deeply prioritizes dominance and potential threat,” he noted. “We literally saw the speed with which these images broke through the unconscious mind and registered on a conscious-level with each key press.”

    For the past decade, Hassin has focused his research on the human unconscious, specifically decision making, memory, motivation and how opinions are formed. “This study gives insight into the unconscious processes that shape our consciousness,” Hassin shared. “These processes are dynamic and often based on personal motivation. Hypothetically, if you’re looking for a romantic partner, your brain will ‘see’ people differently than if you’re already in a relationship. Unconsciously, your brain will ‘prioritize’ faces of potential partners and deemphasize other faces. Likewise, the same might be true for other motivations, such as avoiding danger. Your eyes might pick out certain ‘menacing’ faces from a crowd and avoid them.”

    Looking ahead, Hassin hopes these findings can pave the way towards a better understanding of autism, PTSD and other mental disorders. “It might be possible to train and untrain people from perceiving certain facial dimensions as threatening. This could be helpful for those suffering from PTSD or depression. Likewise, we could train people with autism to be more sensitive to social cues.”

    This work is not only groundbreaking in revealing how our unconscious minds work but in providing scientists with a new set of tools to approach behavioral and mental disorders, as well.


  8. Study finds heightened attention to surprise in veterans with PTSD

    January 5, 2018 by Ashley

    From the Virginia Tech press release:

    Fireworks on nights other than the fourth of July or New Year’s Eve might be nothing more than inconsiderate neighbors, but for veterans with Post Traumatic Stress Disorder (PTSD), the shock of noise and light may trigger a deeply learned expectation of danger.

    Scientists at the Virginia Tech Carilion Research Institute (VTCRI) have found that people with PTSD have an increased learning response to surprising events. While most everyone reacts to surprise, people with PTSD tend to pay even more attention to the unexpected.

    The study was published this week in eLife, an open-access journal published by the Howard Hughes Medical Institute, the Max Planck Society, and the Wellcome Trust.

    “Disproportionate reactions to unexpected stimuli in the environment are a core symptom of PTSD,” said Pearl Chiu, an associate professor at the VTCRI and the lead author on the study. “These results point to a specific disruption in learning that helps to explain why these reactions occur.”

    Chiu and her team used functional MRI to scan the brains of 74 veterans, all of whom had experienced trauma while serving at least one combat tour in Afghanistan or Iraq. Some of the study participants were diagnosed with PTSD, while others were not. In the functional MRI, participants played a gambling game, in which they learned to associate certain choices with monetary gains or losses.

    “Computer science and mathematics have given us new tools to understand how the brain learns. We used these tools to study whether and how learning might play a role in PTSD,” said Chiu, who is also an associate professor of psychology in Virginia Tech’s College of Science. “These results suggest that people with PTSD don’t necessarily have a disrupted response to unexpected outcomes, rather they pay more attention to these surprises,” Chiu said.

    The researchers found that people with PTSD had significantly more activity in the parts of their brains associated with how much attention they paid to surprising events when the learning task threw an unexpected curve ball their way.

    “Fireworks unexpectedly going off after a person has exchanged fire in the field can trigger an over-estimation of danger,” said Brooks King-Casas, an associate professor at the VTCRI who co-led the study. “Particularly for individuals with PTSD, unexpected surprising events — noise or otherwise — could be a matter of life or death. The study shows that while everyone is affected by unexpected events, in PTSD extra attention is given to these surprises.”

    King-Casas is also an associate professor of psychology in Virginia Tech’s College of Science and an associate professor in the Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences.

    Earlier studies have connected greater attention to perceived threats and unexpected events in PTSD, but the mechanistic underpinning of this hypersensitivity to unexpected outcomes have been unclear until now.

    “The work by Brown and colleagues is an important step forward to be able to differentiate the brain and behavioral processes that are affected as a consequence of post-traumatic stress,” said Martin Paulus, a medical doctor and the scientific director and president of the Laureate Institute for Brain Research in Tulsa, Oklahoma. He was not involved in this study. “The finding that individuals with PTSD have difficulty appropriately allocating attention to their environment when it changes has clear implications for the development of novel behavioral interventions.”

    Vanessa Brown, first author on the paper and a graduate student in the department of psychology in Virginia Tech’s College of Science, said that both the behavioral and neural findings show that people with PTSD pay more attention to surprise while learning.

    “This disrupted learning increases with more severe PTSD,” said Brown, who is conducting her dissertation research in Chiu’s laboratory at the VTCRI. “Now that we understand how attention to surprise plays a role in PTSD, we may be able to refine our assessment tools or develop new interventions that target specific learning disruptions in people with PTSD or other psychiatric disorders.”

     


  9. Study suggests journaling inspires altruism through an attitude of gratitude

    January 4, 2018 by Ashley

    From the University of Oregon press release:

    Gratitude does more than help maintain good health. New research at the University of Oregon finds that regularly noting feelings of gratitude in a journal leads to increased altruism.


  10. Study challenges notion that images are appropriate substitute for real objects

    by Ashley

    From the University of Nevada, Reno press release:

    Does having the potential to act upon an object have a unique influence on behavior and brain responses to the object? That is the question Jacqueline Snow, assistant professor of psychology at the University of Nevada, Reno, has set out to answer.

    Her lab examines how and why real tangible objects are processed and represented differently in the human brain compared to representations of objects, such as two-dimensional (2-D) computerized images, three-dimensional (3-D) stereo images, and immersive ‘virtual’ reality displays. Her work investigates real-world cognition using convergent experimental approaches that include behavioral psychophysics, neuropsychology, fMRI, EEG, eye-tracking and augmented reality (AR).

    Snow, with the University’s College of Liberal Arts, and her graduate students, Michael Gomez and Rafal Skiba, recently submitted a paper on the findings of their research study, “Graspable objects grab attention more than images do” which will be published in an upcoming issue of Psychological Science, a top-tier psychology journal.

    Their study looked at whether having the potential to act upon objects influences how humans allocate attention to different objects in a scene. They examined whether real objects compete more strongly for attention and manual responses compared to matched computerized 2-D and 3-D images of the same objects.

    To answer this question, the authors used a ‘flanker’ paradigm, in which healthy human observers were asked to make quick responses to a central target stimulus, while ignoring irrelevant objects that flanked the target from above and below. We typically take longer to respond to a central target (e.g., a spoon with a rightward-oriented handle) when it is flanked by distractors that would elicit a different manual response to that of the target (e.g., spoons with leftward-oriented handles). Slower reaction times to the target reflect the extent to which the irrelevant flankers have captured attention.

    The authors hypothesized that because real objects afford genuine actions (i.e., grasping) they should be more powerful competitors for attention than 2-D or 3-D images of the same objects (which do not allow grasping). In line with this idea, the study found the irrelevant real object flankers slowed response times to the central target more than the 2-D or 3D image flankers. Critically, however, this effect disappeared when the stimuli were placed out of reach of the observer, as well as when the stimuli were presented within reach, but behind a large transparent barrier that prevented the opportunity for manual interaction with the stimuli.

    Together, the results demonstrate, for the first time, that real objects exert a more powerful influence on attention and manual responses than do computerized images of objects, because images are not relevant for action.

    “These results challenge the long-held notion that images are appropriate proxies for real objects in the study of human brain function,” Snow said. “These findings suggest a number of exciting avenues for future research, such as whether similar effects are found when observers look at more immersive 3-D stimuli presented using augmented reality (AR) displays. AR stimuli are particularly interesting to us because the observer can grasp and move the (virtual) objects.”

    Other findings from the Snow lab include discovering that the human brain responds differently to real objects versus 2-D photos of objects and that real objects are more memorable than 2-D images. Snow, together with her students Carissa Romero and Michael Compton, have also discovered recently that snack foods presented as real objects are valued more than snacks presented as 2-D images — a study soon to be published in the journal Cortex.

    Snow went on to explain that the study raises important questions in the field of psychology.

    “These findings are important because much of what we know about the human brain and cognition is based on studies that have relied on relatively impoverished 2D images presented on a computer screen,” Snow explained. “In my lab, we are investigating how, and why, the brain processes real, tangible objects differently to images. Humans appear to be very sensitive to whether or not they are looking at an image, or a real object, and whether the object itself is within reach.”