Posts tagged brain scans
Articles and news from the latest research reports.
The Quantified Brain of a Self-Tracking Neuroscientist
A neuroscientist is getting a brain scan twice every week for a year to try to see how neural networks behave over time
Russell Poldrack, a neuroscientist at the University of Texas at Austin, is undertaking some intense introspection. Every day, he tracks his mood and mental state, what he ate, and how much time he spent outdoors. Twice a week, he gets his brain scanned in an MRI machine. And once a week, he has his blood drawn so that it can be analyzed for hormones and gene activity levels. Poldrack plans to gather a year’s worth of brain and body data to answer an unexplored question in the neuroscience community: how do brain networks behave and change over a year?
Can Brain Scans Really Tell Us What Makes Something Beautiful?
When art meets neuroscience, strange things happen.
Consider the Museum of Scientifically Accurate Fabric Brain Art in Oregon which features rugs and knitting based on a brain scan motif. Or the neuroscientist at the University of Nevada-Reno who scanned the brain of a portrait artist while he drew a picture of a face.
And then there’s the ongoing war of words between scientists who think it’s possible to use analysis of brain activity to define beauty–or even art–and their critics who argue that it’s absurd to try to make sense of something so interpretive and contextual by tying it to biology and the behavior of neurons.
Beauty and the brain
On one side you have the likes of Semir Zeki, who heads a research center called the Institute of Neuroesthetics at London’s University College. A few years ago he started studying what happens in a person’s brain when they look at a painting or listen to a piece of music they find beautiful. He looked at the flip side, too–what goes on in there when something strikes us as ugly.
What he found is that when his study’s subjects experienced a piece of art or music they described as beautiful, their medial orbito-frontal cortex–the part of the brain just behind the eyes–”lit up” in brain scans. Art they found ugly stimulated their motor cortex instead. Zeki also discovered that whether the beauty came through their ears, in music, or their eyes, in art, the brain’s response was the same–it had increased blood flow to what’s known as its pleasure center. Beauty gave the brains a dopamine reward.
Zeki doesn’t go so far as to suggest that the essence of art can be captured in a brain scan. He insists his research really isn’t about explaining what art is, but rather what our neurons’ response to it can tell us about how brains work. But if, in the process, we learn about common characteristics in things our brains find beautiful, his thinking goes, what harm is there in that?
Beware of brain rules?
Plenty, potentially, responds the critics’ chorus. Writing recently in the journal Nature, Philip Ball makes the point that this line of research ultimately could lead to rule-making about beauty, to “creating criteria of right or wrong, either in the art itself or in individual reactions to it.” It conceivably could devolve to “scientific” formulas for beauty, guidelines for what, in music or art or literature, gets the dopamine flowing.
Adds Ball:
Although it is worth knowing that musical ‘chills’ are neurologically akin to the responses invoked by sex or drugs, an approach that cannot distinguish Bach from barbiturates is surely limited.
Others, such as University of California philosophy professor Alva Noe, suggest that to this point at least, brain science is too limiting in what it can reveal, that it focuses more on beauty as shaped by people’s preferences, as opposed to addressing the big questions, such as “Why does art move us?” and “Why does art matter?”
And he wonders if a science built around analyzing events in an individual’s brain can ever answer them. As he wrote in the New York Times:
…there can be nothing like a settled, once-and-for-all account of what art is, just as there can be no all-purpose account of what happens when people communicate or when they laugh together. Art, even for those who make it and love it, is always a question, a problem for itself. What is art? The question must arise, but it allows no definitive answer.
Fad or fortune?
So what of neuroaesthetics? Is it just another part of the “neuro” wave, where brain scans are being billed as neurological Rosetta Stones that proponents claim can explain or even predict behavior–from who’s likely to commit crimes to why people make financial decisions to who’s going to gain weight in the next six months.
More jaded souls have suggested that neuroaesthetics and its bulky cousin, neurohumanities, are attempts to capture enough scientific sheen to attract research money back to liberal arts. Alissa Quart, writing in The Nation earlier this month, cut to the chase:
Neurohumanities offers a way to tap the popular enthusiasm for science and, in part, gin up more funding for humanities. It may also be a bid to give more authority to disciplines that are more qualitative and thus are construed, in today’s scientized and digitalized world, as less desirable or powerful.
Samir Zeki, of course, believes this is about much more than research grants. He really isn’t sure where neuroaesthetics will lead, but he’s convinced that only by “understanding the neural laws,” as he puts it, can we begin to make sense of morality, religion and yes, art.
Women’s, men’s brains respond differently to hungry infant’s cries
Researchers at the National Institutes of Health have uncovered firm evidence for what many mothers have long suspected: women’s brains appear to be hard-wired to respond to the cries of a hungry infant.
Researchers asked men and women to let their minds wander, then played a recording of white noise interspersed with the sounds of an infant crying. Brain scans showed that, in the women, patterns of brain activity abruptly switched to an attentive mode when they heard the infant cries, whereas the men’s brains remained in the resting state.
“Previous studies have shown that, on an emotional level, men and women respond differently to the sound of an infant crying,” said study co-author Marc H. Bornstein, Ph.D., head of the Child and Family Research Section of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the institute that conducted the study. “Our findings indicate that men and women show marked differences in terms of attention as well.”
The earlier studies showed that women are more likely than men to feel sympathy when they hear an infant cry, and are more likely to want to care for the infant.
Dr. Bornstein collaborated with Nicola De Pisapia, Ph.D., Paola Rigo, Simona DeFalco, Ph.D., and Paola Venuti, Ph.D., all of the Observation, Diagnosis and Education Lab at the University of Trento, Italy, and Gianluca Esposito, Ph.D., of RIKEN Brain Science Institute, Japan.
Their findings appear in NeuroReport.
Previous studies have shown differences in patterns of brain activity between when an individual’s attention is focused and when the mind wanders. The pattern of unfocused activity is referred to as default mode, Dr. Bornstein explained. When individuals focus on something in particular, their brains disengage from the default mode and activate other brain networks.
For about 15 minutes, participants listened to white noise interspersed with short periods of silence and with the sounds of a hungry infant crying. The patterns of their brain activity were recorded by a technique known as functional magnetic resonance imaging.
The researchers analyzed brain images from 18 adults, parents and nonparents. The researchers found that when participants listened to the typical infant cries, the brain activity of men and women differed. When hearing a hungry infant cry, women’s brains were more likely to disengage from the default mode, indicating that they focused their attention on the crying. In contrast, the men’s brains tended to remain in default mode during the infant crying sounds. The brain patterns did not vary between parents and nonparents.
Infants cry because they are distressed, hungry, or in need of physical closeness. To determine if adults respond differently to different types of cries, the researchers also played the cries of infants who were later diagnosed with autism. An earlier study of Dr. Bornstein and the same Italian group found that the cries of infants who develop ASD tend to be higher pitched than those of other infants and that the pauses between cries are shorter. In this other study, both men and women tended to interrupt their mind wandering when they heard these cries.
“Adults have many-layered responses to the things infants do,” said Dr. Bornstein. “Determining whether these responses differ between men and women, by age, and by parental status, helps us understand instincts for caring for the very young.”
In an earlier study, Dr. Bornstein and his colleagues found that patterns of brain activity in men and women also changed when they viewed an image of an infant face and that the patterns were indicative of a predisposition to relate to and care for the infant.
Such studies documenting the brain activity patterns of adults represent first stages of research in neuroscience understanding how adults relate to and care for infants, Dr. Bornstein explained. It is possible that not all adults exhibit the brain patterns seen in these studies.
Size, wiring of brain structures in kids predict benefit from math tutoring
Why do some children learn math more easily than others? Research from the Stanford University School of Medicine has yielded an unexpected new answer.
In a study of third-graders’ responses to math tutoring, Stanford scientists found that the size and wiring of specific brain structures predicted how much an individual child would benefit from math tutoring. However, traditional intelligence measures, such as children’s IQs and their scores on tests of mathematical ability, did not predict improvements from tutoring.
The research is the first to use brain scans to look for a link between math-learning abilities and brain structure or function, and also the first to compare neural and cognitive predictors of kids’ responses to tutoring. In addition, it provides information on the differences between how children and adults learn math, and could help researchers understand the origins of math-learning disabilities.
The study was published online April 29 in Proceedings of the National Academy of Sciences.
"What was really surprising was that intrinsic brain measures can predict change - we can actually predict how much a child is going to learn during eight weeks of math tutoring based on measures of brain structure and connectivity," said Vinod Menon, PhD, the study’s senior author and a professor of psychiatry and behavioral sciences. Menon is also a member of the Child Health Research Institute at Lucile Packard Children’s Hospital.
"The results are a significant step toward the development of targeted learning programs based on a child’s current as well as predicted learning trajectory," said the study’s lead author, Kaustubh Supekar, PhD, postdoctoral scholar in psychiatry and behavioral sciences.
Menon’s team focused on third-grade students ages 8 and 9 because these children are at a critical stage for acquiring basic arithmetic skills. The study included 24 third-graders who participated in a well-validated program of 15 to 20 hours of individualized math tutoring over eight weeks. The tutors explained new concepts to children and also got them to practice math skills with an emphasis on speed, and the sessions were tailored to each child’s level of understanding.
Before tutoring began, the children were given several standard neuropsychological assessments, including tests of IQ, working memory, reading and math-problem-solving abilities. Both before and after the eight-week tutoring period, children’s arithmetic performance was tested, and all children had structural and functional magnetic resonance imaging scans performed on their brains. To control for the effects of math instruction the children received at school (rather than during tutoring), a comparison group of 16 third-grade children who did not receive tutoring, but who had the same testing and brain scans before and after an eight-week interval, was also included in the study.
All 24 children receiving tutoring improved their arithmetic performance. Their performance efficiency, a composite measure of accuracy and speed of problem solving, improved an average of 67 percent after tutoring. But individual gains varied widely, ranging from 8 percent to 198 percent improvement. The children who did not receive tutoring did not show any change in arithmetic performance during the study.
When the researchers analyzed the children’s structural brain scans, they found that larger gray matter volume in three brain structures predicted greater ability to benefit from math tutoring. (The predictions were generated with a machine learning algorithm, the same type of data-analysis tool used to create movie recommendations for users of websites like Netflix, for example.) Of the three structures, the best predictor of improvement with tutoring was a larger hippocampus, a structure traditionally considered one of the brain’s most important memory centers. Functional connections between the hippocampus and several other brain regions, especially the prefrontal cortex and basal ganglia, also predicted ability to benefit from tutoring. These regions are important for forming long-term memories.
"The part of the brain that is recruited in memories for places and events also plays a pivotal role in determining how much and how well a child learns math," Supekar said.
None of the neuropsychological assessment scores, such as IQ or tests of working memory, could predict how much an individual child would benefit from tutoring.
The brain systems highlighted by this study - including the hippocampus, basal ganglia and prefrontal cortex - are different from those previously implicated for math learning in adults, the researchers noted. When solving math problems, adults rely on brain regions that are specialized for representing complex visual objects and processing spatial information.
And the findings suggest that the tutoring approach used, which was tailored to each child’s level of understanding and included lots of repetitive, high-speed arithmetic practice to help cement facts in children’s heads, works because it is compatible with the way their brains encode facts. “Memory resources provided by the hippocampal system create a scaffold for learning math in the developing brain,” Menon said. “Our findings suggest that, while conceptual knowledge about numbers is necessary for math learning, repeated, speeded practice and testing of simple number combinations is also needed to encode facts and encourage children’s reliance on retrieval - the most efficient strategy for answering simple arithmetic problems.” Once kids are able to pull up answers to basic arithmetic problems automatically from memory, their brains can tackle more complex problems.
The researchers’ next steps will include comparing brain structure and wiring in children with and without math learning disabilities, analyzing how the wiring of the brain changes in response to tutoring and examining whether lower-performing children’s brains can be exercised to help them learn math. “We’re pushing a very ecologically relevant model of learning,” Menon said. “Academic instruction should rely on validated instructional principles while incorporating individualized training to provide feedback on whether students are right or wrong, how they’re wrong and how they can improve their math skills.”
(Source: med.stanford.edu)
Brain Scans Reveal That Humans Definitely Feel Empathy For Robots
While creating an empathetic robot is a long-held dream, understanding whether humans genuinely empathise with robots should — in theory — be easier. Now, a team of scientists have analysed fMRI brain scans to reveal that humans have similar brain function when shown affection and violence being inflicted on both humans and robots.
The experiments, conducted at the University of Duisburg, Essen, had 40 participants sit and watch videos of a small dinosaur-shaped robot. It was either treated in an affectionate or violent way, and then researchers measured physiological arousal — finding overwhelmingly strong reaction to the scenes of violence. A second study used functional magnetic-resonance imaging, and shows that affectionate interaction towards both robots and humans resulted in similar neural activation patterns in the brain.
That suggests that those actions elicit similar reactions for interactions with both humans and robots. The problem with most experiments on this subject is that participants generally choose not to report emotional reaction to robots — an fMRI scan gets around that problem. Rosenthal-von der Pütten, one of the researchers, explains the implications of the findings:
“One goal of current robotics research is to develop robotic companions that establish a long-term relationship with a human user, because robot companions can be useful and beneficial tools. They could assist elderly people in daily tasks and enable them to live longer autonomously in their homes, help disabled people in their environments, or keep patients engaged during the rehabilitation process. A common problem is that a new technology is exciting at the beginning, but this effect wears off especially when it comes to tasks like boring and repetitive exercise in rehabilitation. The development and implementation of uniquely humanlike abilities in robots like theory of mind, emotion and empathy is considered to have the potential to solve this dilemma.”
The scientists present their findings at the 63rd Annual International Communication Association conference in London in June.
Memory, the Adolescent Brain, and Lying: Understanding the Limits of Neuroscientific Evidence in the Law
Brain scans are increasingly able to reveal whether or not you believe you remember some person or event in your life. In a new study presented at a cognitive neuroscience meeting today, researchers used fMRI brain scans to detect whether a person recognized scenes from their own lives, as captured in some 45,000 images by digital cameras. The study is seeking to test the capabilities and limits of brain-based technology for detecting memories, a technique being considered for use in legal settings.
“The advancement and falling costs of fMRI, EEG, and other techniques will one day make it more practical for this type of evidence to show up in court,” says Francis Shen of the University of Minnesota Law School, who is chairing a session on neuroscience and the law at a meeting of the Cognitive Neuroscience Society (CNS) in San Francisco this week. “But technological advancement on its own doesn’t necessarily lead to use in the law.” But as the technology has advanced and as the legal system desires to use more empirical evidence, neuroscience and the law are intersecting more often than in previous decades.
In U.S. courts, neuroscientific evidence has been used largely in cases involving brain injury litigation or questions of impaired ability. In some cases outside the United States, however, courts have used brain-based evidence to check whether a person has memories of legally relevant events, such as a crime. New companies also are claiming to use brain scans to detect lies – although judges have not yet admitted this evidence in U.S. courts. These developments have rallied some in the neuroscience community to take a critical look at the promise and perils of such technology in addressing legal questions – working in partnership with legal scholars through efforts such as the MacArthur Foundation Research Network on Law and Neuroscience.
Recognizing your own memories
What inspired Anthony Wagner, a cognitive neuroscientist at Stanford University, to test fMRI uses for memory detection was a case in June 2008 in Mumbai, India, in which a judge cited EEG evidence as indicating that a murder suspect held knowledge about the crime that only the killer could possess. “It appeared that the brain data held considerable sway,” says Wagner, who points out that the methods used in that case have not been subject to extensive peer review.
Since then, Wagner and colleagues have conducted a number of experiments to test whether brain scans can be used to discriminate between stimuli that people perceive as old or new, as well as more objectively, whether or not they have previously encountered a particular person, place, or thing. To date, Wagner and colleagues have had success in the lab using fMRI-based analyses to determine whether someone recognizes a person or perceives them as unfamiliar, but not in determining whether in fact they have actually seen them before.
In a new study presented today, his team sought to take the experiments out of the lab and into the real world by outfitting participants with digital cameras around their necks that automatically took photos of the participants’ everyday experiences. Over a multi-week period, the cameras yielded 45,000 photos per participant.
Wagner’s team then took brief photo sequences of individual events from the participants’ lives and showed them to the participants in the fMRI scanner, along with photo sequences from other subjects as the control stimuli. The researchers analyzed their brain patterns to determine whether or not the participants were recognizing the sequences as their own. “We did quite well with most subjects, with a mean accuracy of 91% in discriminating between event sequences that the participant recognized as old and those that the participant perceived as unfamiliar, ” Wagner says. “These findings indicate that distributed patterns of brain activity, as measured with fMRI, carry considerable information about an individual’s subjective memory experience – that is, whether or not they are remembering the event.”
In another new study, Wagner and colleagues tested whether people can “beat the technology” by using countermeasures to alter their brain patterns. Back in the lab, the researchers showed participants individual faces and later asked them whether the faces were old or new. “Halfway through the memory test, we stopped and told them ‘What we are actually trying to do is read out from your brain patterns whether or not you are recognizing the face or perceiving it as novel, and we’ve been successful with other subjects in doing this in the past. Now we want you to try to beat the system by altering your neural responses.’” The researchers instructed the participants to think about a familiar person or experience when presented with a new face, and to focus on a novel feature of the face when presented a previously encountered face.
“In the first half of the test, during which participants were just making memory decisions, we were well above chance in decoding from brain patterns whether they recognized face or perceived it as novel. However, in the second half of the test, we were unable to classify whether or not they recognized the face nor whether the face was objectively old or new,” Wagner says. Within a forensic setting, Wagner says, it is conceivable that a suspect could use such measures to try to mask the brain patterns associated with memory.
Wagner says that his work to date suggests that the technology may have some utility in reading out brain patterns in cooperative individuals but that the uses are much more uncertain with uncooperative individuals. However, Wagner stresses that the method currently does not distinguish well between whether a person’s memory reflects true or false recognition. He says that it is premature to consider such evidence in the courts because many additional factors await future testing, including the effects of stress, practice, and time between the experience and the memory test.
Overgeneralizing the adolescent brain
A general challenge to the use of neuroscientific evidence in legal settings, Wagner says, is that most studies are at the group rather than the individual level. “The law cares about a particular individual in a particular situation right in front of them,” he says, and the science often cannot speak to that specificity.
Shen cites the challenge of making individualized inference from group-based data as one of the major ones facing use of neuroscience evidence in the court. “This issue has come up in the context of juvenile justice, where the adolescent brain development data confirms behavioral data that on average 17-year-olds are more impulsive than adults, but does not tell us whether a particular 17-year-old, namely the one on trial, was less able to control his/her actions on the day and in the manner in question,” he says.
Indeed, B.J. Casey of the Weill Medical College of Cornell University says that too often we overgeneralize the lack of self control among adolescents. Although adolescents do show poor self control as a group, some situations and individuals are more prone to this breakdown than others.
“It is not that teens can’t make decisions, they can and they can do so efficiently,” Casey says. “It is when they must make decisions in the heat of the moment – in presence of potential or perceived threats, among peers – that the court should consider diminished responsibility of teens while still holding them accountable for their behavior.” Research suggests that this diminished ability is due to the immature development of circuitry involved in processing of negative or positive cues in the environment in the subcortical limbic regions and then in regulating responses to those cues in the prefrontal cortex.
The body of research to date is at the group-level, however, and is not yet able to comment on the neurobiological maturity of an individual adolescent. To help provide more guidance on this issue in legal settings, Casey and colleagues are working alongside legal scholars on a developmental imaging study, funded by the MacArthur Foundation, that is examining behaviors relevant to juvenile criminal behavior, including impulsivity and peer influence.
Making real-world connections
The same type of work – to connect brain imaging to particular behaviors in the real-world – is ongoing in a number of other areas, including fMRI-based lie detection and linking negligence to specific mental states. “It’s a big leap to go from a laboratory setting, in which impulse control may be measured by one’s ability to not press a button in response to a stimulus, to the real-world, where the question is whether someone had requisite self-control not to tie up an innocent person and throw them off a bridge.” Shen says. “I don’t see neuroscience solving these big problems anytime soon, and so the question for law becomes: What do we do with this uncertainty? I think this is where we’re at right now, and where we’ll be for some time.”
“With a few notable exceptions such as death penalty cases, cases where a juvenile is facing a very stiff sentence, and litigating brain injury claims, ‘law and neuroscience’ is not familiar to most lawyers,” Shen says. “But this might change – and soon.” The ongoing work is vital, he says, for laying a foundation for a future that’s yet to come, and he hopes that more neuroscientists will increasingly collaborate with legal scholars.
System Provides Clear Brain Scans of Awake, Unrestrained Mice
Setting a mouse free to roam might alarm most people, but not so for nuclear imaging researchers from the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility, Oak Ridge National Laboratory, Johns Hopkins Medical School and the University of Maryland who have developed a new imaging system for mouse brain studies.
Scientists use dynamic imaging of mice to follow changes in brain chemistry caused by the progression of disease or the application of a drug as an effective research tool for developing better ways to diagnose disease and formulate better treatments. In most nuclear imaging studies, laboratory mice are typically drugged or bound in place so that their brains can be studied. However, the results of such research can be tainted by subjecting the mice to such chemical or physical restraints, complicating studies of Alzheimer’s, dementia and Parkinson’s disease.
But for their nuclear medicine imaging studies, the researchers from Jefferson Lab, Oak Ridge, Johns Hopkins and Maryland used a new system they developed to acquire functional images of the brains of conscious, unrestrained and un-anesthetized mice. The so-called AwakeSPECT system was then used to document for the first time the effects of anesthesia on the action of a dopamine transporter imaging compound in the mouse brain. Such dopamine transporter imaging compounds are used for Alzheimer’s, dementia and Parkinson’s disease studies.
SPECT is Single-Photon Emission Computed Tomography. In this technique, a radionuclide is injected, where it collects in specific areas of the brain by function. The radionuclide emits gamma rays (single photons) that are collected by a detector in separate scans from many different angles. The scans are combined in an algorithm to produce a three-dimensional image.
"The AwakeSPECT system does regular SPECT imaging of mice. SPECT is a nuclear medicine imaging technique that’s used in humans for various types of diagnostic studies. It’s also used in animal studies to facilitate the development and understanding of disease physiology," says Jefferson Lab’s Drew Weisenberger, who led the multi-institutional collaboration and directed the SPECT system development effort.
Weisenberger says the AwakeSPECT system uses two Jefferson Lab custom-built gamma cameras to image the radionuclide, as well as a system that processes the data to produce the three-dimensional images. An infrared camera system developed at Oak Ridge National Laboratory tracks movement of the mouse. Finally, a commercially available CT system provides additional anatomical information.
Researchers at Johns Hopkins Medical School, led by Martin Pomper, conducted the first mouse imaging studies with the new system. To prepare a mouse for imaging with AwakeSPECT, it is first tagged with three markers that are glued to its head for the infrared system to track. Once the radionuclide is injected, the mouse can then be imaged as it rests in a homey, burrow-like, clear tube. The beauty of the system is that it doesn’t require that the mouse (or potentially people, at a later stage) remain motionless. Two patents have been awarded to Jefferson Lab for the innovative technology associated with this system.
"We developed this system that, while acquiring SPECT images, uses infrared cameras that track the location and pose of the head. We use that information to then computationally remove motion artifacts from our SPECT imaging," he says.
In this recent study published online in The Journal of Nuclear Medicine, the researchers showed that AwakeSPECT can obtain detailed, functional images of the brain of a conscious mouse, as the mouse moves around freely in an enclosure.
Researchers also imaged the action of a drug often used to image dopamine transport in the brain, 123I-ioflupane, in awake and anesthetized mice. They found that the drug was absorbed less than half as well in awake mice, showing that the use of anesthetic could potentially confound drug uptake studies.
"We’ve shown the technology works. Now, you just have to make it a tool that more people will readily use" Weisenberger says.
Weisenberger says the next step is to improve the AwakeSPECT imager by upgrading the infrared tracking system, using newer technology for the SPECT imager, and by making the system more intuitive for animal researchers to operate.
Brain-imaging tool and stroke risk test help identify cognitive decline early
UCLA researchers have used a brain-imaging tool and stroke risk assessment to identify signs of cognitive decline early on in individuals who don’t yet show symptoms of dementia.
The connection between stroke risk and cognitive decline has been well established by previous research. Individuals with higher stroke risk, as measured by factors like high blood pressure, have traditionally performed worse on tests of memory, attention and abstract reasoning.
The current small study demonstrated that not only stroke risk, but also the burden of plaques and tangles, as measured by a UCLA brain scan, may influence cognitive decline.
The imaging tool used in the study was developed at UCLA and reveals early evidence of amyloid beta “plaques” and neurofibrillary tau “tangles” in the brain — the hallmarks of Alzheimer’s disease.
The study, published in the April issue of the Journal of Alzheimer’s Disease, demonstrates that taking both stroke risk and the burden of plaques and tangles into accout may offer a more powerful assessment of factors determining how people are doing now and will do in the future.
"The findings reinforce the importance of managing stroke risk factors to prevent cognitive decline even before clinical symptoms of dementia appear," said first author Dr. David Merrill, an assistant clinical professor of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior at UCLA.
This is one of the first studies to examine both stroke risk and plaque and tangle levels in the brain in relation to cognitive decline before dementia has even set in, Merrill said.
According to the researchers, the UCLA brain-imaging tool could prove useful in tracking cognitive decline over time and offer additional insight when used with other assessment tools.
For the study, the team assessed 75 people who were healthy or had mild cognitive impairment, a risk factor for the future development of Alzheimer’s. The average age of the participants was 63.
The individuals underwent neuropsychological testing and physical assessments to calculate their stroke risk using the Framingham Stroke Risk Profile, which examines age, gender, smoking status, systolic blood pressure, diabetes, atrial fibrillation (irregular heart rhythm), use of blood pressure medications, and other factors.
In addition, each participant was injected with a chemical marker called FDDNP, which binds to deposits of amyloid beta plaques and neurofibrillary tau tangles in the brain. The researchers then used positron emission tomography (PET) to image the brains of the subjects — a method that enabled them to pinpoint where these abnormal proteins accumulate.
The study found that greater stroke risk was significantly related to lower performance in several cognitive areas, including language, attention, information-processing speed, memory, visual-spatial functioning (e.g., ability to read a map), problem-solving and verbal reasoning.
The researchers also observed that FDDNP binding levels in the brain correlated with participants’ cognitive performance. For example, volunteers who had greater difficulties with problem-solving and language displayed higher levels of the FDDNP marker in areas of their brain that control those cognitive activities.
"Our findings demonstrate that the effects of elevated vascular risk, along with evidence of plaques and tangles, is apparent early on, even before vascular damage has occurred or a diagnosis of dementia has been confirmed," said the study’s senior author, Dr. Gary Small, director of the UCLA Longevity Center and a professor of psychiatry and biobehavioral sciences who holds the Parlow–Solomon Chair on Aging at UCLA’s Semel Institute.
Researchers found that several individual factors in the stroke assessment stood out as predictors of decline in cognitive function, including age, systolic blood pressure and use of blood pressure–related medications.
Small noted that the next step in the research would be studies with a larger sample size to confirm and expand the findings.
Human Emotion: We Report Our Feelings in 3-D
Like it or not and despite the surrounding debate of its merits, 3-D is the technology du jour for movie-making in Hollywood. It now turns out that even our brains use 3 dimensions to communicate emotions.
According to a new study published in Biological Psychiatry, the human report of emotion relies on three distinct systems: one system that directs attention to affective states (“I feel”), a second system that categorizes these states into words (“good”, “bad”, etc.); and a third system that relates the intensity of affective responses (“bad” or “awful”?).
Emotions are central to the human experience. Whether we are feeling happy, sad, afraid, or angry, we are often asked to identify and report on these feelings. This happens when friends ask us how we are doing, when we talk about professional or personal relationships, when we meditate, and so on. In fact, the very commonness and ease of reporting what we are feeling can lead us to overlook just how important such reports are - and how devastating the impairment of this ability may be for individuals with clinical disorders ranging from major depression to schizophrenia to autism spectrum disorders.
Progress in brain science has steadily been shedding light on the circuits and processes that underlie mood states. One of the leaders in this effort, Dr. Kevin Ochsner, Director of the Social Cognitive Neuroscience Lab at Columbia University, studies the neural bases of social, cognitive and affective processes. In this new study, he and his team set out to study the processes involved in constructing self-reports of emotion, rather than the effects of the self-reports or the emotional states themselves for which there is already much research.
To accomplish this, they recruited healthy participants who underwent brain scans while completing an experimental task that generated a self-report of emotion. This effort allowed the researchers to examine the neural architecture underlying the emotional reports.
“We find that the seemingly simple ability is supported by three different kinds of brain systems: largely subcortical regions that trigger an initial affective response, parts of medial prefrontal cortex that focus our awareness on the response and help generate possible ways of describing what we are feeling, and a part of the lateral prefrontal cortex that helps pick the best words for the feelings at hand,” said Ochsner.
“These findings suggest that self-reports of emotion - while seemingly simple - are supported by a network of brain regions that together take us from an affecting event to the words that make our feelings known to ourselves and others,” he added. “As such, these results have important implications for understanding both the nature of everyday emotional life - and how the ability to understand and talk about our emotions can break down in clinical populations.”
Dr. John Krystal, Editor of Biological Psychiatry, said, “It is critical that we understand the mechanisms underlying the absorption in emotion, the valence of emotion, and the intensity of emotion. In the short run, appreciation of the distinct circuits mediating these dimensions of emotional experience helps us to understand how brain injury, stroke, and tumors produce different types of mood changes. In the long run, it may help us to better treat mood disorders.”
![Brain scans predict which criminals are more likely to reoffend
In a twist that evokes the dystopian science fiction of writer Philip K. Dick, neuroscientists have found a way to predict whether convicted felons are likely to commit crimes again from looking at their brain scans. Convicts showing low activity in a brain region associated with decision-making and action are more likely to be arrested again, and sooner.
Kent Kiehl, a neuroscientist at the non-profit Mind Research Network in Albuquerque, New Mexico, and his collaborators studied a group of 96 male prisoners just before their release. The researchers used functional magnetic resonance imaging (fMRI) to scan the prisoners’ brains during computer tasks in which subjects had to make quick decisions and inhibit impulsive reactions.
The scans focused on activity in a section of the anterior cingulate cortex (ACC), a small region in the front of the brain involved in motor control and executive functioning. The researchers then followed the ex-convicts for four years to see how they fared.
Among the subjects of the study, men who had lower ACC activity during the quick-decision tasks were more likely to be arrested again after getting out of prison, even after the researchers accounted for other risk factors such as age, drug and alcohol abuse and psychopathic traits. Men who were in the lower half of the ACC activity ranking had a 2.6-fold higher rate of rearrest for all crimes and a 4.3-fold higher rate for nonviolent crimes. The results are published in the Proceedings of the National Academy of Sciences.
There is growing interest in using neuroimaging to predict specific behaviour, says Tor Wager, a neuroscientist at the University of Colorado in Boulder. He says that studies such as this one, which tie brain imaging to concrete clinical outcomes, “provide a new and so far very promising way” to find patterns of brain activity that have broader implications for society.But the authors themselves stress that much more work is needed to prove that the technique is reliable and consistent, and that it is likely to flag only the truly high-risk felons and leave the low-risk ones alone. “This isn’t ready for prime time,” says Kiehl.
Wager adds that the part of the ACC examined in this study “is one of the most frequently activated areas in the human brain across all kinds of tasks and psychological states”. Low ACC activity could have a variety of causes — impulsivity, caffeine use, vascular health, low motivation or better neural efficiency — and not all of these are necessarily related to criminal behaviour.
Crime prediction was the subject of Dick’s 1956 short story “The Minority Report” (adapted for the silver screen by Steven Spielberg in 2002), which highlighted the thorny ethics of arresting people for crimes they had yet to commit.
Brain scans are of course a far cry from the clairvoyants featured in that science-fiction story. But even if the science turns out to be reliable, the legal and social implications remain to be explored, the authors warn. Perhaps the most appropriate use for neurobiological markers would be for helping to make low-stakes decisions, such as which rehabilitation treatment to assign a prisoner, rather than high-stakes ones such as sentencing or releasing on parole.
“A treatment of [these clinical neuroimaging studies] that is either too glibly enthusiastic or over-critical,” Wager says, “will be damaging for this emerging science in the long run.”](http://36.media.tumblr.com/c6cebc407bf78e353f3f88b1bd0f655f/tumblr_mk9lbbb0yz1rog5d1o1_500.jpg)
Brain scans predict which criminals are more likely to reoffend
In a twist that evokes the dystopian science fiction of writer Philip K. Dick, neuroscientists have found a way to predict whether convicted felons are likely to commit crimes again from looking at their brain scans. Convicts showing low activity in a brain region associated with decision-making and action are more likely to be arrested again, and sooner.
Kent Kiehl, a neuroscientist at the non-profit Mind Research Network in Albuquerque, New Mexico, and his collaborators studied a group of 96 male prisoners just before their release. The researchers used functional magnetic resonance imaging (fMRI) to scan the prisoners’ brains during computer tasks in which subjects had to make quick decisions and inhibit impulsive reactions.
The scans focused on activity in a section of the anterior cingulate cortex (ACC), a small region in the front of the brain involved in motor control and executive functioning. The researchers then followed the ex-convicts for four years to see how they fared.
Among the subjects of the study, men who had lower ACC activity during the quick-decision tasks were more likely to be arrested again after getting out of prison, even after the researchers accounted for other risk factors such as age, drug and alcohol abuse and psychopathic traits. Men who were in the lower half of the ACC activity ranking had a 2.6-fold higher rate of rearrest for all crimes and a 4.3-fold higher rate for nonviolent crimes. The results are published in the Proceedings of the National Academy of Sciences.
There is growing interest in using neuroimaging to predict specific behaviour, says Tor Wager, a neuroscientist at the University of Colorado in Boulder. He says that studies such as this one, which tie brain imaging to concrete clinical outcomes, “provide a new and so far very promising way” to find patterns of brain activity that have broader implications for society.
But the authors themselves stress that much more work is needed to prove that the technique is reliable and consistent, and that it is likely to flag only the truly high-risk felons and leave the low-risk ones alone. “This isn’t ready for prime time,” says Kiehl.
Wager adds that the part of the ACC examined in this study “is one of the most frequently activated areas in the human brain across all kinds of tasks and psychological states”. Low ACC activity could have a variety of causes — impulsivity, caffeine use, vascular health, low motivation or better neural efficiency — and not all of these are necessarily related to criminal behaviour.
Crime prediction was the subject of Dick’s 1956 short story “The Minority Report” (adapted for the silver screen by Steven Spielberg in 2002), which highlighted the thorny ethics of arresting people for crimes they had yet to commit.
Brain scans are of course a far cry from the clairvoyants featured in that science-fiction story. But even if the science turns out to be reliable, the legal and social implications remain to be explored, the authors warn. Perhaps the most appropriate use for neurobiological markers would be for helping to make low-stakes decisions, such as which rehabilitation treatment to assign a prisoner, rather than high-stakes ones such as sentencing or releasing on parole.
“A treatment of [these clinical neuroimaging studies] that is either too glibly enthusiastic or over-critical,” Wager says, “will be damaging for this emerging science in the long run.”