In a recent study, Sebastian Guderian and colleagues examined the relation between theta oscillations and memory performance. During the study phase of this memory experiment, participants were presented with words and either performed a semantic or phonemic encoding task (there were two levels of processing used in this experiment). During the study phase, the researchers obtained whole-head MEG recordings. Later on during the test phase, the participants were given a free-recall test on the words that were presented to them during the study phase.

Interestingly, Guderian and colleagues found that amplitudes of theta oscillations that shortly preceded the presentation of the words were higher for those words that were later recalled during the free-recall test, compared to those words that were later forgotten.

Although past studies have shown that specific patterns of brain activity are associated with the encoding of items, this study by Guderian and colleagues is one of a handful of more recent studies that demonstrate pre-stimulus brain activity that is associated with later memory performance (another example is a study by Otten and colleagues).

Moreover, although semantic study tasks typically lead to better memory performance compared to phonemic tasks, the results of the study by Guederian and colleagues suggest that this study task benefit is not only statistically independent from the theta-related recall benefit, but that these benefits are additive.

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From the Dana Foundation: We might begin to learn a dance step when someone describes it to us, but we learn it better when we physically perform the steps as we observe and imitate an instructor doing them. Scott Grafton’s research sheds light on the brain’s action observation network, which fires up both when we perform an action and when we watch someone else perform it. Dr. Grafton contends that his and others’ findings highlight the importance of including physical learning in the classroom, to stimulate creativity, increase motivation and bolster social intelligence.

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One way to describe brain activity measured by EEG or MEG is by its frequency content. Frequencies can be categorized into one of the following ranges: low, middle and high. The low frequencies include the delta and theta ranges, whereas the middle frequency range consists of the alpha and beta ranges. The gamma wave belongs to the high frequency group.

Different cognitive functions have been associated with these different frequency ranges. Specifically, alpha oscillations have been associated with the inhibition of brain regions that are not required to perform a given task. However, in a past paper, Palva and Palva summarized an accumulating body of evidence that suggested that alpha oscillations play a much larger role in cognition by contributing to mechanisms of attention and consciousness. Click here for full access to the paper.

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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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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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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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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.

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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.

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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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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.”

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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.

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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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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.

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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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