October 9, 2009
1/f scaling (or 1/f noise) refers to a scaling relation followed by fluctuations that have been widely observed in nature. 1/f fluctuations have been observed ubiquitously across different disciplines of science (e.g. chemistry, psychology, biology). In specific relation to cognitive neuroscience, 1/f scaling has been observed widely in fMRI measurement series and treated, generally, as noise to work around as opposed to an object of study. The challenge is that since 1/f fluctuations seem to be present throughout the brain, they do not help localize specific cognitive functions to specific areas of the brain. However, studies have shown that the appearance of 1/f fluctuations in fMRI measurements change as a function of cognitive variables.
Whereas some researchers argue that 1/f scaling is a byproduct of processes that are irrelevant to theories of cognition, others argue that 1/f fluctuations reflect a general and essential principle of emergent pattern formation in complex systems, including cognitive systems.
In a past study Kello, Beltz, Holden and Van Orden examined the relevance of 1/f scaling to cognitive function in four experiments using simple and choice response tasks. (For full access to the paper, click here.) The results of this study supported the emergent coordination argument and the researchers concluded that “the generality of 1/f scaling in cognitive performance is evidence that cognitive functions are universally formed as emergent patterns of physiological and behavioral activity”.
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October 5, 2009
U. Voss, R. Holzmann, I. Tuin, J.A. Hobson
Article in Sleep
Abstract
Study Objectives: The goal of the study was to seek physiological correlates of lucid dreaming. Lucid dreaming is a dissociated state with aspects of waking and dreaming combined in a way so as to suggest a specific alteration in brain physiology for which we now present preliminary but intriguing evidence. We show that the unusual combination of hallucinatory dream activity and wake-like reflective awareness and agentive control experienced in lucid dreams is paralleled by significant changes in electrophysiology.
Design: 19-channel EEG was recorded on up to 5 nights for each participant. Lucid episodes occurred as a result of pre-sleep autosuggestion.
Setting: Sleep laboratory of the Neurological Clinic, Frankfurt University.
Participants: Six student volunteers who had been trained to become lucid and to signal lucidity through a pattern of horizontal eye movements.
Measurements and Results: Results show lucid dreaming to have REM-like power in frequency bands delta and theta, and higher-than-REM activity in the gamma band, the between-states-difference peaking around 40 Hz. Power in the 40 Hz band is strongest in the frontal and frontolateral region. Overall coherence levels are similar in waking and lucid dreaming and significantly higher than in REM sleep, throughout the entire frequency spectrum analyzed. Regarding specific frequency bands, waking is characterized by high coherence in alpha, and lucid dreaming by increased delta and theta band coherence. In lucid dreaming, coherence is largest in frontolateral and frontal areas.
Conclusions: Our data show that lucid dreaming constitutes a hybrid state of consciousness with definable and measurable differences from waking and from REM sleep, particularly in frontal areas.
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May 19, 2009
From the Dana Foundation: The Dana Foundation released at a news conference on March 4, Learning, Arts, and the Brain, a three-year study at seven universities, which finds strong links between arts education and cognitive development. Speakers included Michael Gazzaniga, Ph.D., UC, Santa Barbara; Michael Posner, Ph.D., University of Oregon; Elizabeth Spelke, Ph.D., Harvard University and Brian Wandell, Ph.D., Stanford University. Guy Mckhann, M.D., Johns Hopkins University gave a summary and Dana Gioia, chairman of the National Endowment for the Arts spoke of the study’s importance to the field of education.
Click here for the webcast archive.
Click here for the event transcript.
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April 10, 2009
Ken A. Paller, Joel L.Voss, Carmen E. Westerberg
Article in Perspectives on Psychological Science
Abstract
There is a marked lack of consensus concerning the best way to learn how conscious experiences arise. In this article, we advocate for scientific approaches that attempt to bring together four types of phenomena and their corresponding theoretical accounts: behavioral acts, cognitive events, neural events, and subjective experience. We propose that the key challenge is to comprehensively specify the relationships among these four facets of the problem of understanding consciousness without excluding any facet. Although other perspectives on consciousness can also be informative, combining these four perspectives could lead to significant progress in explaining a conscious experience such as remembering. We summarize some relevant findings from cognitive neuroscience investigations of the conscious experience of memory retrieval and of memory behaviors that transpire in the absence of the awareness of remembering. These examples illustrate suitable scientific strategies for making progress in understanding consciousness by developing and testing theories that connect the behavioral expression of recall and recognition, the requisite cognitive transactions, the neural events that make remembering possible, and the awareness of remembering.
Click here for the full paper.
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February 17, 2009
In a recent study, Sheline and colleagues examined whether patients with major depression were impaired in their ability to regulate the activity of the default mode network, which is characterized by self-referential functions. To do so, they used fMRI to measure changes in brain activity occurring within this network in 20 individuals with major depression and 21 demographically similar control participants. The depressed and healthy control participants were asked to examine negative pictures passively and also to reappraise them actively.
In contrast to the depressed participants, the healthy control participants demonstrated reduced activity in widely distributed regions of the default mode network (ventromedial prefrontal cortex, prefrontal cortex, anterior cingulate, lateral parietal cortex, and lateral temporal cortex) while looking at the negative pictures and reappraising them. Moreover, compared to the healthy control participants, the depressed participants demonstrated a larger increase in activity in other default mode network regions (amygdala, parahippocampus, and hippocampus) while they looked at negative pictures.
Based on these data, Sheline and colleagues suggest that depression is characterized by both a stimulus-induced increase in brain activity and a failure to broadly decrease the activity of the default mode network. Further, the authors suggest that these findings provide a brain network framework within which to consider the pathophysiology of depression.
Click here for full access to the study.
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February 16, 2009
We often make social comparisons to evaluate others and ourselves. In a recent study in Science, Takahashi and colleagues investigated the neurocognitive mechanisms of envy and schadenfreude (pleasure at another’s misfortune) using fMRI. The researchers found that envy and schadenfreude are associated with different parts of the brain. Whereas envy was associated with the dorsal anterior cingulate cortex, schadenfreude was associated with the ventral striatum. The dorsal anterior cingulate is involved in the processing of cognitive conflicts; envy-related activation in this region was greater when the envied person had superior and more self-relevant characteristics. The ventral striatum is involved in processing reward and the schadenfreude-related activity in this region was stronger when misfortune befell an envied person more so than a neutral person. Additionally, envy-related activity in the anterior cingulate predicted schadenfreude-related activity in the ventral striatum. Takahashi and colleagues suggest that their findings document mechanisms of painful emotion, envy, and a rewarding reaction, schadenfreude.
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January 17, 2009
From the Dana Foundation: Learning, Arts, and the Brain, a study three years in the making, is the result of research by cognitive neuroscientists from seven leading universities across the United States. In the Dana Consortium study, released in March 2008, researchers grappled with a fundamental question: Are smart people drawn to the arts or does arts training make people smarter?
For the first time, coordinated, multi-university scientific research brings us closer to answering that question. Learning, Arts, and the Brain advances our understanding of the effects of music, dance, and drama education on other types of learning. Children motivated in the arts develop attention skills and strategies for memory retrieval that also apply to other subject areas.
The research was led by Dr. Michael S. Gazzaniga of the University of California at Santa Barbara. “A life-affirming dimension is opening up in neuroscience,” said Dr. Gazzaniga, “to discover how the performance and appreciation of the arts enlarge cognitive capacities will be a long step forward in learning how better to learn and more enjoyably and productively to live. The consortium’s new findings and conceptual advances have clarified what now needs to be done.”
Click here for complete article
Click here to download a a PDF version of the full report (2MB)
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From The Dana Foundation: My great-grandmother lived to the ripe old age of 98. While many of her friends and neighbors had lost critical cognitive function decades before, requiring assistance for day-to-day activities, she somehow maintained her faculties well enough to live on her own well into her 90s. What was it about my great-grandmother’s brain-and those of others like her-that allowed her to retain these essential cognitive capabilities? Researchers at Northwestern University and elsewhere are shedding some light on the so-called “super-aged,” offering new insight into the aging brain and memory.
Click here for complete article.
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November 24, 2008
Christoph Börgers, Steven Epstein, and Nancy J. Kopell
Article in Proceedings of the National Academy of Science, USA
Abstract
Simultaneous presentation of multiple stimuli can reduce the firing rates of neurons in extrastriate visual cortex below the rate elicited by a single preferred stimulus. We describe computational results suggesting how this remarkable effect may arise from strong excitatory drive to a substantial local population of fast-spiking inhibitory interneurons, which can lead to a loss of coherence in that population and thereby raise the effectiveness of inhibition. We propose that in attentional states fast-spiking interneurons may be subject to a bath of inhibition resulting from cholinergic activation of a second class of inhibitory interneurons, restoring conditions needed for gamma rhythmicity. Oscillations and coherence are emergent features, not assumptions, in our model. The gamma oscillations in turn support stimulus competition. The mechanism is a form of “oscillatory selection,” in which neural interactions change phase relationships that regulate firing rates, and attention shapes those neural interactions.
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Informing the debate over the reality of ‘free will’ requires learning something about the lateral habenula.
From ScienceNews: At the end of The Matrix trilogy, Neo and Agent Smith are engaged in one final, interminable scene of surreal combat, a surrogate competition for an eternal battle between humans and machines. “It’s pointless to keep fighting,” Agent Smith declares to Neo. “Why do you persist?”
“Because I choose to,” Neo replies, just before the computer-generated Smith meets his demise in a cinematic celebration of human free will’s superiority to the programming that enslaves machines. Machines are mindless. The brain is a decider.
All very inspiring, except that the brain itself is a machine, a network of cells that computes its choices based on the sum of sensory inputs and their interactions with neural anatomy. “Free will” is not the defining feature of humanness, modern neuroscience implies, but is rather an illusion that endures only because biochemical complexity conceals the mechanisms of decision making.
Yet belief in free will persists as stubbornly as Neo’s resistance to electronic tyranny. Whether supposedly free choice is actually a Matrix-like mirage remains one of the great questions of human philosophical history. For centuries that question was assessed mostly with thought -uninformed by actual neurobiological knowledge. Nowadays, though, the inner workings of the brain are revealing themselves to modern methods of neuroinquiry, and free will seems merely to emerge from electrochemical networks of neuronal interactions. But like tourists exploring a strange city without a GPS map, scientists don’t know how all the neural neighborhoods are connected and occasionally encounter surprising enclaves-such as a place in the brain called the lateral habenula.
“There’s lots of new research showing that an overactive habenula has behavioral effects,” says neuropharmacologist Martine Mirrione of Brookhaven National Laboratory in Upton, N.Y.
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November 3, 2008
From The Dana Foundation: Imagine you are playing a game of poker. Watching your opponent, you have a gut feeling that if you raise the bet, he will fold. You decide to go with your intuition and it works.
Were you just lucky?
According to neuroscientist Mathias Pessiglione, the gut feeling you experienced could be the result of your brain picking up subliminal cues from your opponent and associating them with a positive outcome. Pessiglione uses a poker game as a possible real-life example of the kind of subliminal instrumental conditioning that he and his colleagues at the Institut National de la santé et de la recherche médicale (INSERM), a public research institute in Paris, have demonstrated for the first time in the human brain.
They report the results of a carefully designed study using a system of masked cues matched to win or loss outcomes in the Aug. 28 issue of the journal Neuron.
Click here for complete article.
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October 31, 2008
From Reuters: CANBERRA (Reuters) – The Internet is not just changing the way people live but altering the way our brains work with a neuroscientist arguing this is an evolutionary change which will put the tech-savvy at the top of the new social order.
Gary Small, a neuroscientist at UCLA in California who specializes in brain function, has found through studies that Internet searching and text messaging has made brains more adept at filtering information and making snap decisions.
But while technology can accelerate learning and boost creativity it can have drawbacks as it can create Internet addicts whose only friends are virtual and has sparked a dramatic rise in Attention Deficit Disorder diagnoses.
Small, however, argues that the people who will come out on top in the next generation will be those with a mixture of technological and social skills.
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December 10, 2007
From physorg.com — Following ground-breaking research showing that neurons in the human brain respond in an abstract manner to particular individuals or objects, University of Leicester researchers have now discovered that, from the firing of this type of neuron, they can tell what a person is actually seeing.
The original research by Dr R Quian Quiroga, of the University’s Department of Engineering, showed that one neuron fired to, for instance, Jennifer Aniston, another one to Halle Berry, another one to the Sydney Opera House, etc. The responses were abstract. For example, the neuron firing to Halle Berry responded to several different pictures of her and even to the letters of her name, but not to other people or names.
This result, published in Nature in 2005 and selected as one of the top 100 scientific stories of the year by Discover Magazine, came from data from patients suffering from epilepsy. As candidates for epilepsy surgery, they are implanted with intracranial electrodes to determine as accurately as possible the area where the seizures originate. From that, clinicians can evaluate the potential outcome of curative surgery.
Dr Quian Quiroga’s latest research, which has appeared in the Journal of Neurophysiology, follows on from this. Dr Quian Quiroga explained:
“For example, if the ‘Jennifer Aniston neuron’ increases its firing then we can predict that the subject is seeing Jennifer Aniston. If the ‘Halle Berry neuron’ fires, then we can predict that the subject is seeing Halle Berry, and so on. “To do this, we used and optimised a ‘decoding algorithms’, which is a mathematical method to infer the stimulus from the neuronal firing. We also needed to optimise our recording and data processing tools to record simultaneously from as many neurons as possible. Currently we are able to record simultaneously from up to 100 neurons in the human brain.
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November 18, 2007
Psychophysiology was the first journal dedicated to the publication of research on relationships between the physiological and psychological aspects of brain and behavior, and it remains the most well-established journal in this field. This prestigious international journal continues to play a key role in advancing psychophysiological science and human neuroscience. Psychophysiology reports on new theoretical, empirical, and methodological advances that inform psychology and psychiatry, cognitive science, cognitive and affective neuroscience, social science, health science and behavioral medicine, biomedical engineering, and signal processing and statistics.
Since its inception in 1964, Psychophysiology has published seminal papers relevant to the role of regional brain specialization in perceptual, cognitive, and emotional function. The journal’s commitment to brain imaging has been continuously evident as the field has both specialized and expanded, encompassing a wide variety of techniques and tools including high-density EEG, MEG, magnetic source imaging (MEG + MRI), and near-infrared spectroscopy. Psychophysiology continues this publication tradition by featuring papers that employ functional MRI (fMRI). Indeed, fMRI is the quintessential psychophysiological measure, revealing fundamental relationships between psychological processes and physiological measures of their neural substrate.
We are interested in papers that expand the application of fMRI to illuminate a wide variety of psychological phenomena, both normative and clinical. Given Psychophysiology’s long tradition of publishing innovative methodological and statistical papers, we also welcome manuscripts reporting innovative techniques for fMRI.
Manuscripts should be submitted electronically at http://mc.manuscriptcentral.com/psyp. Submissions should include a brief cover letter indicating that informed consent was obtained from human subjects and that human or infrahuman subjects were treated in accordance with appropriate ethical guidelines. Manuscripts must conform to the specifications of the Publication Manual of the American Psychological Association, 5th edition.
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October 31, 2007
Combining the latest research foci and treatment modalities, the Second Annual International Brain Conference at UCF offers physicians, scientists, pharmaceuticals, medical device manufacturers, nurses, allied medical professionals and students the opportunity to learn about the absolute latest in brain research and practice. Participants will also be able to earn Continuing Medical & Psychological credits.
Held at UCF’s beautiful Rosen College of Hospitality Management in the heart of Orlando’s tourist district, the Second International
Brain Conference at UCF features keynote speaker Dr. Konrad Beyreuther, recipient of the Potamkin Prize and the Henry M. Wisniewski Award for Lifetime Achievement in Alzheimer’s Disease Research. Beyreuther’s work laid the foundation for understanding the molecular processes that lead to Alzheimer’s Disease.
On opening night Special Guest Mark McEwen, weatherman and entertainment reporter on the CBS Early Show for 16 years, will tell his inspiring personal story: “Stroke: My Recovery Story and the Regenerative Powers of Hope and Rehabilitation.”
Take advantage of early registration rates that end December 1. Special rates are also available for ADI members. Register now at
www.brainconference.org or call 407-882-1576 for more information.
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April 23, 2007
It seems like science still has a ways to go before this question can be answered, but scientists have already started the investigation. In a recent study, Mason and colleagues used fMRI and thought sampling to study which areas of the brain show increased activations in one kind of situation where our minds are likely to wander: when we perform tasks that become banal with continual practice. They compared brain activity that was associated with performing blocks of well-practiced tasks with that of non-practiced, but otherwise identical, tasks and observed greater activation for the practiced tasks in following brain areas: bilateral medial prefrontal cortex (BAs 6, 8, 9, and 10); bilateral superior frontal gyri (BAs 8 and 9); anterior cingulate (BA10); bilateral aspects of the posterior cingulate (BAs 29 and 30); precuneus (BAs 7 and 31); left angular gyrus (BA 39); bilateral aspects of the insula (BA 13); left superior temporal (BA 22), the right superior temporal (BA 41) and the left middle temporal gyri (BA 19). They also found a significant positive relation between changes in brain activity in many of the aforementioned regions for blocks in which subjects performed practiced, relative to non-practiced, tasks and the subjects’ frequency of mind-wandering, which was assessed using the daydream frequency scale of the Imaginal Processes Inventory. Following-up with this intriguing study, it would be interesting to examine the brain activity that arises during specific instances, as opposed to blocks, when participants report mind-wandering.
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February 19, 2007
February 8, 2007
There is an interesting paper, The Medial Temporal Lobe Distinguishes Old from New Independently of Consciousness in The Journal of Neuroscience. The novel part is that the MTL novelty distinction can operate at an unconscious level. From one perspective the MTL is traditionally thought to be part of a declarative memory system, suggesting that a majority—if not all—of the processing here involves consciousness. This result thus suggests that at least for this function, consciousness does not need to be an issue. What seems amiss in this paper is the more detailed account of MTL regions. Several studies have documented—both for humans and non-human primates—that different parts of the MTL make different contributions to the novelty distinction. Specifically, the perirhinal cortex is thought to be the primary processor of old/new distinctions. Clickthrough for abstract.
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For a long time psychologists have devised methods to make people erroneous on a task. A well-known example is the Stroop effect, a demonstration of interference in the reaction time of a task. When a word such as blue, green, red, etc. is printed in a colour differing from the colour expressed by the word’s semantic meaning (e.g. the word “red” printed in blue ink), a delay occurs in the processing of the word’s colour, leading to slower test reaction times and an increase in mistakes.
The study of the neural correlates of the Stroop effect have revealed, among other correlates, an increased activation in the prefrontal cortex. But what happens if you discover that you have made a mistake and try to correct it? This kind of “error awareness” has now been documented in a recent study published in NeuroImage. We here bring the abstract and a poster.
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February 2, 2007
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