Biological Psychology Links

By Gero Miesenböck In 1937 the great neuroscientist Sir Charles Scott Sherrington of the University of Oxford laid out what would become a classic description of the brain at work. He imagined points of light signaling the activity of nerve cells and their connections. During deep sleep, he proposed, only a few remote parts of the brain would twinkle, giving the organ the appearance of a starry night sky. But at awakening, “it is as if the Milky Way entered upon some cosmic dance,” Sherrington reflected. “Swiftly the head-mass becomes an enchanted loom where millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of subpatterns.” Although Sherrington probably did not realize it at the time, his poetic metaphor contained an important scientific idea: that of the brain revealing its inner workings optically. Understanding how neurons work together to generate thoughts and behavior remains one of the most difficult open problems in all of biology, largely because scientists generally cannot see whole neural circuits in action. The standard approach of probing one or two neurons with electrodes reveals only tiny fragments of a much bigger puzzle, with too many pieces missing to guess the full picture. But if one could watch neurons communicate, one might be able to deduce how brain circuits are laid out and how they function. This alluring notion has inspired neuroscientists to attempt to realize Sherrington’s vision. © 1996-2008 Scientific American Inc

by Andy Smith a.t.smith@rhul.ac.uk Wade A. R et al. (2002). Functional measurements of human ventral occipital cortex: retinotopy and colour. Phil. Trans. R. Soc. Lond. B., 357:963-973. During the recent boom in functional MRI, vision research has led the way in terms of detailed, quantitative analysis. The main focus of cognitive MRI research has been to identify ‘blobs’ that show significant activity in given cognitive circumstances. This is an essential first step, but does not address the nature of the processing that occurs in the areas so identified. In contrast, vision researchers knew already where to look (at the very back of the brain), and have been mapping the surface of the visual cortex, almost millimetre by millimetre, addressing issues of functional organisation on a much finer scale. This methodological lead has been made possible by the pre-existence of copious physiological and anatomical information about the visual system of other primates. Because of this lead, at a recent Royal Society meeting in London on ‘the physiology of cognitive processes’ the presentations on vision were among the most eagerly received. One of these, presented by Wandell and now published along with the other contributions, illustrates just how far into the visual cortex the fine-scale approach can be taken. © Elsevier Science Limited 2002

Kerri Smith Scientists have developed a way of ‘decoding’ someone’s brain activity to determine what they are looking at. “The problem is analogous to the classic ‘pick a card, any card’ magic trick,” says Jack Gallant, a neuroscientist at the University of California in Berkeley, who led the study. But while a magician uses a ploy to pretend to ‘read the mind’ of the subject staring at a card, now researchers can do it for real using brain-scanning instruments. “When the deck of cards, or photographs, has about 120 images, we can do better than 90% correct,” says Gallant. The technique is a step towards being able to see the contents of someone’s visual experiences. “You can imagine using this for dream analysis, or psychotherapy,” says Gallant. Already the results are helping to provide neuroscientists with a more accurate model of how the human visual system works. If the work can be broadened to developing more general models of how the brain responds to things beyond visual stimuli, such brain scans could help to diagnose disease or monitor the effects of therapy. © 2008 Nature Publishing Group

By Alexis Madrigal Email Author Neuroscientist Craig Bennett purchased a whole Atlantic salmon, took it to a lab at Dartmouth, and put it into an fMRI machine used to study the brain. The beautiful fish was to be the lab’s test object as they worked out some new methods. So, as the fish sat in the scanner, they showed it “a series of photographs depicting human individuals in social situations.” To maintain the rigor of the protocol (and perhaps because it was hilarious), the salmon, just like a human test subject, “was asked to determine what emotion the individual in the photo must have been experiencing.” The salmon, as Bennett’s poster on the test dryly notes, “was not alive at the time of scanning.” methodsIf that were all that had occurred, the salmon scanning would simply live on in Dartmouth lore as a “crowning achievement in terms of ridiculous objects to scan.” But the fish had a surprise in store. When they got around to analyzing the voxel (think: 3-D or “volumetric” pixel) data, the voxels representing the area where the salmon’s tiny brain sat showed evidence of activity. In the fMRI scan, it looked like the dead salmon was actually thinking about the pictures it had been shown. “By complete, random chance, we found some voxels that were significant that just happened to be in the fish’s brain,” Bennett said. “And if I were a ridiculous researcher, I’d say, ‘A dead salmon perceiving humans can tell their emotional state.’” © 2009 Cond� Nast Digital.

St. Louis, May 29, 2001 – Scientists have discovered that, unlike many other animals, humans have a reserve of oxygen in the brain. This buffer allows the brain to adapt to arduous situations without demanding a sharp increase in blood flow. "Our finding challenges the previously accepted idea that blood flow increases occur during tasks such as reading to raise oxygen levels in the brain," says study leader Mark A. Mintun, M.D. "That idea has been long assumed in brain imaging studies that attempt to understand how the human brain functions."

CHAMPAIGN, Ill. - A non-invasive diagnostic tool that can study changes occurring at the surface of the brain because of brain activity has been developed by scientists at the University of Illinois. The technique is based upon near-infrared spectroscopy and is simpler to use and less expensive than other methods such as functional magnetic resonance imaging and positron emission tomography. "Whenever a region of the brain is activated – directing movement in a finger, for example – that part of the brain uses more oxygen," said Enrico Gratton, a UI professor of physics. "Our technique works by measuring the blood flow and oxygen consumption in the brain."

CHAMPAIGN, Ill. - A new approach to improving the detection and removal of tumors has been developed by scientists at the University of Illinois. Similar in operation to ultrasound, optical coherence tomography (OCT) is an optical technique that allows high-resolution imaging of tissue. The technique works by focusing a beam of near-infrared light (like that used in CD players) into tissue and measuring the intensity and position of the resulting reflections. To make OCT work better, UI researchers have developed injectable contrast agents that will help identify tumors early in their growth. "OCT is a relatively new technology that is just beginning to be used in the clinical setting," said Stephen Boppart, a professor of electrical and computer engineering and of bioengineering. "No doubt there will be many instances where we will need to improve the contrast." In collaboration with UI chemistry professor Ken Suslick, Boppart and his students have developed microspheres that enhance the contrast for OCT. The tiny spheres – filled with air or some other light-scattering media – create a stronger signal than the surrounding tissue.

COLUMBUS, Ohio – Researchers have developed a new way to use a decade-old imaging method to directly compare the brains of monkeys with those of humans. Their report appeared in the journal Science. The method uses functional Magnetic Resonance Imaging (fMRI) – a technique that measures blood volume and flow and blood-oxygen levels in the brain. It also provides an indirect measure of neuronal activity in different regions of the brain. Neurons need oxygen and glucose to work. Blood carries both substances, and both can cross the blood-brain barrier. When a particular region of the brain is activated, the blood flow to that area temporarily increases in order to supply the neurons with fresh oxygen and glucose.

MRI used in a breakthrough study to explore how we gather information - Bethesda, MD – How do we learn? At the same time, when learning is conscious, does the brain engage in learning based on experience? Many scientists have believed that the two processes are independent of each other. Now, new research findings published in the current edition of the Journal of Neurophysiology, suggest otherwise. Procedural learning, such as perceptual-motor sequence learning, is thought to be an obligatory consequence of practiced performance and to reflect adaptive plasticity in the neural systems mediating performance. Prior neuroimaging studies, however, have found that sequence learning accompanied with awareness (declarative learning) of the sequence activates entirely different brain regions than learning without awareness of the sequence (procedural learning). However, conflicts between imaging and behavioral studies have not resolved whether true independence exists between the two brain functions.

- Bethesda, MD – In 1968, country music singer Johnny Cash recorded the fictional lament of a convict in Folsom prison. The lyrics, "I hear the train a comin'; it's rollin' 'round the bend, And I ain't seen the sunshine since I don't know when, ©" contain an acoustic anomaly, the sound of a train. Despite its insight into human nature, it's unlikely Cash knew that the sound of a train would be the catalyst for new research findings into how the brain processes auditory repetition rates. We encounter differing rates of sound each day that are important in the perception of the more complex acoustic conditions. Since repetition rate plays a fundamental role in determining how sounds are heard, it is not surprising that there have been numerous neurophysiological studies of rate in animals. Broad trends concerning the coding of rate in the auditory pathway have emerged from this work. For instance, the highest repetition rates at which neurons respond faithfully to each successive sound in a train (or each successive cycle of amplitude modulated stimuli) tends to decrease from brain stem to thalamus to cortex. While animal studies have shed light on the neural representations of repetition rate, the degree to which the animal findings are related to humans' remains uncertain because of interspecies differences, anesthesia differences, and a paucity of data in humans that can serve as a link to the animal work. In the end, direct neurophysiological data in human listeners is important to understand how repetition rate is represented in the activity patterns of the human brain.

Tool sheds light on which specific brain cells are active and when TROY, N.Y. — The mind works in mysterious ways, and one Rensselaer researcher and his colleagues have created a computer automation tool to help solve those mysteries, speed understanding of how the brain develops, delve more deeply into brain function at the cellular level, and make more reliable conclusions Rensselaer engineering professor Badri Roysam has developed a technology called Quantitative cat-FISH that analyzes 3-D, microscopic images of the brains of rats after the animals have run through mazes. By logging important cognitive cellular information — such as activity, cell shape, size, and location — in a simple spreadsheet for analysis, the software is helping researchers identify which cells are active and when. In the past, researchers have only been able to pinpoint which general regions of the brain are active. Researchers used to perform some of the time-consuming cell counting and transcription work that Quantitative cat-FISH does by hand. Roysam's system now allows scientists to process more data and tissue faster and without subjective error. It also enables researchers to make more reliable conclusions. Copyright © 1996–2003 Rensselaer Polytechnic Institute.

By Sarah Yang, Media Relations BERKELEY – New findings by researchers at the University of California, Berkeley, could significantly improve the resolution of scans from functional magnetic resonance imaging, one of neuroscience's most powerful research tools to date. Functional MRI (fMRI) is a non-invasive procedure that detects increased levels of blood flow into certain areas of the brain to infer neural activity. But in a study published Feb. 14 in the journal Science, researchers from UC Berkeley's Group in Vision Science show that an initial decrease in oxygen levels is an earlier and more spatially precise signal of nerve cell activity. The findings could lead to fMRI scans with a more detailed resolution measured in micrometers. Most current fMRI techniques have a resolution of a few millimeters. There is hope that the new findings can provide the groundwork for research that will translate into future clinical use, such as earlier detection of brain and neurologic disorders such as Alzheimer's or Parkinson's Diseases. Copyright UC Regents

A team of researchers led by cognitive scientist Elizabeth Bates, a professor at the University of California, San Diego, has developed a novel new brain imaging technique that produces maps that “light up” the relationship between the severity of a behavioral deficit and the voxels (similar to pixels in computer images) in the brain that contribute the most to that deficit. Discovery of the new technique, known as Voxel-based Lesion-Symptom Mapping (VLSM), was reported in the April 21 issue of Nature Neuroscience. According to Bates, who is known for her research on the brain and how it is organized to process language, VLSM will give researchers an invaluable new tool for pinpointing the specific areas of the brain that are most crucial for normal functioning during critical brain activities, starting with the measures of language comprehension and production that were used for the first demonstration in Nature Neuroscience, but moving on to many different language and non-language functions. To view or download the paper, which includes color VLSM brain maps, please visit: “This is a new brain mapping technique to be used with structural rather than functional magnetic resonance imaging scans (fMRI) that locate brain damage for individual patients,” said Bates. “It is an important breakthrough because it is a bridge, a tool, to bring two completely different traditions in brain research – lesion-behavior mapping and fMRI’s -- into alignment.” Copyright ©2001 Regents of the University of California

HANOVER, N.H. – A new Dartmouth study reveals that interracial contact has a profound impact on a person's attention and performance. The researchers found new evidence using brain imaging that white individuals attempt to control racial bias when exposed to black individuals, and that this act of suppressing bias exhausts mental resources. Published in the online edition of Nature Neuroscience on Nov. 16, the study combines the use of functional magnetic resonance imaging (fMRI), which measures brain activity, with other behavioral tests common to research in social and cognitive psychology to determine how white individuals respond to black individuals. "We were surprised to find that brain activity in response to faces of black individuals predicted how research participants performed on cognitive tasks after actual interracial interactions," says Jennifer Richeson, Assistant Professor of Psychological and Brain Sciences, the lead author on the paper. "To my knowledge, this is the first study to use brain imaging data in tandem with more standard behavioral data to test a social psychological theory."

The brain's center of reasoning and problem solving is among the last to mature, a new study graphically reveals. The decade-long magnetic resonance imaging (MRI) study of normal brain development, from ages 4 to 21, by researchers at NIH's National Institute of Mental Health (NIMH) and University of California Los Angeles (UCLA) shows that such "higher-order" brain centers, such as the prefrontal cortex, don't fully develop until young adulthood. A time-lapse 3-D movie that compresses 15 years of human brain maturation, ages 5 to 20, into seconds shows gray matter – the working tissue of the brain's cortex – diminishing in a back-to-front wave, likely reflecting the pruning of unused neuronal connections during the teen years. Cortex areas can be seen maturing at ages in which relevant cognitive and functional developmental milestones occur. The sequence of maturation also roughly parallels the evolution of the mammalian brain, suggest Drs. Nitin Gogtay, Judith Rapoport, NIMH, and Paul Thompson, Arthur Toga, UCLA, and colleagues, whose study is published online during the week of May 17, 2004 in The Proceedings of the National Academy of Sciences. "To interpret brain changes we were seeing in neurodevelopmental disorders like schizophrenia, we needed a better picture of how the brain normally develops," explained Rapoport.

PITTSBURGH--Carnegie Mellon University neuroscientist Alison Barth has developed the first tool to identify and study individual neurons activated in a living animal. This advance, described in the July 21 issue of The Journal of Neuroscience, ultimately could lead to the development of targeted drugs that directly affect specific neurons involved in neurological diseases that alter behavior, learning and perception. While neuroscientists have made great strides in identifying the general areas of the brain that perform certain tasks, these methods have worked at the gross level and with poor resolution, according to Barth, an assistant professor of biological sciences at the university's Mellon College of Science. To overcome these limitations, Barth created a transgenic mouse that couples the green fluorescent protein (GFP) with the gene c-fos, which turns on when nerve cells are activated. Using this method, researchers can see specific neurons glow as they are activated by external stimuli such as sensory experience or drug treatment. "Our transgenic mouse is a novel tool that can be used to visualize, in living brain tissue, a single neuron that has been activated in response to an animal's experience," Barth said. Barth used the fosGFP mice to identify neurons that are activated during a specific rearing condition – experiencing the world through one whisker. By locating a cluster of glowing neurons, she was able to precisely identify the area of the brain involved in processing sensory input from the single whisker.

Washington -- Researchers at the Boston Veterans Affairs Health Care System – Brockton Division, Harvard Medical School, and the University of Massachusetts-Boston are using new imaging technology to gather valuable information about the brains of people with schizophrenia. This new variety of magnetic resonance imaging (MRI) is called diffusion tensor imaging (DTI). Using DTI on patients with schizophrenia, neuropsychologists have related smaller sizes in two distinct webs of brain fibers to two distinct types of cognitive malfunction. The findings appear in the October issue of Neuropsychology, which is published by the American Psychological Association (APA). Diffusion tensor imaging (DTI) uses a regular MRI machine to analyze the movement of water molecules in and around the fibers that connect different parts of the brain. Neuroscientists use DTI to track indicators of brain "connectivity" – factors such as the number, thickness, density and arrangement of axons (the hair-like extensions of neurons, which send messages to other neurons) and thickness of the insulating/conducting fatty myelin sheath in which they are embedded. If weaker structural integrity reduces connectivity, lead author Paul Nestor, PhD, says it may mean that, "different brain areas do not communicate as well – with less synchrony or harmony, akin to an orchestra or band playing out of synch."

It's a scene football fans will see over and over during the bowl and NFL playoff seasons: a player, often the quarterback, being slammed to the ground and hitting the back of his head on the landing. Sure, it hurts, but what happens to the inside of the skull? Researchers and doctors long have relied upon crude approximations made from test dummy crashes or mathematical models that infer – rather loosely – what happens to the brain during traumatic brain injury or concussion. But the truth is that the state of the art in understanding brain deformation after impact is rather crude and uncertain because such methods don't give any true picture of what happens. Now, mechanical engineers at Washington University in St. Louis and collaborators have devised a technique on humans that for the first time shows just what the brain does when the skull accelerates.

ANN ARBOR, Mich. -- It happens to all of us, no matter how hard we try. Whether it's deleting a computer file and realizing a split-second later that we can't get it back, or dropping a bag of groceries, or realizing that our gas tank is nearly empty on a lonely stretch of highway, we all make mistakes that aren't just annoying, but potentially costly. Now, a team of University of Michigan researchers has looked inside the human brain and captured the instant when someone makes a costly mistake. What they've found is interesting by itself, but may also help scientists understand mental health problems such as obsessive-compulsive disorder, or OCD. In general, the U-M scientists found that a particular part of the brain called the rostral anterior cingulate cortex, or rACC, becomes much more active when a person realizes he or she has made an error that carries consequences – for instance, losing money. By contrast, the same area of the brain doesn't show the same level of activity when the mistake doesn't carry a penalty, or even when a correct action carries a reward. The rACC is thought to be involved with emotional responses, and scientists had suspected it might also be involved in response to costly errors. But this is the first brain-imaging study to test that idea.

WINSTON-SALEM, N.C. – Using positron emission tomography (PET), researchers have established a firm connection between a particular brain chemistry trait and the tendency of an individual to abuse cocaine and possibly become addicted, suggesting potential treatment options. The research, in animals, shows a significant correlation between the number of receptors in part of the brain for the neurotransmitter dopamine – measured before cocaine use begins – and the rate at which the animal will later self-administer the drug. The research was conducted in rhesus monkeys, which are considered an excellent model of human drug users. Generally the lower the initial number of dopamine receptors, the higher the rate of cocaine use, the researchers found. The research was led by Michael A. Nader, Ph.D., professor of physiology and pharmacology at Wake Forest University School of Medicine. It was already known that cocaine abusers had lower levels of a particular dopamine receptor known as D2, in both human and animal subjects, compared to non-users. But it was not known whether that was a pre-existing trait that predisposed individuals to cocaine abuse or was a result of cocaine use. "The present findings in monkeys suggest that both factors are likely to be true," Nader and colleagues write in a study published online this week in the journal Nature Neuroscience.

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