May 28, 2011

A Conversation on the Neuroethics of Deep Brain Stimulation

In this webcast provided by the Dana Foundation, Drs. Philip Campbell, Joseph Fins, Jonathan Moreno and Helen Mayberg discussed the ethical considerations of using deep brain stimulation. The topics covered in this interesting discussion included surgical experimentation, consciousness, depression, technology and public policy. Dr. Judy Illes served as the moderator.

Click here for the webcast.

Click here for an edited transcript of the discussion.

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April 20, 2011

Addiction and Brain Circuits

From Brain Briefings:

Humans have always struggled with addictions to mind-altering substances. Yet, only in the past few decades have neuroscientists begun to understand precisely how these substances affect the brain — and why they can quickly become a destructive and even deadly habit. 

For a long time, society viewed addiction as a moral failing. The addict was seen as someone who simply lacked self-control. Today, thanks to new advances in brain imaging and other technologies, we know that addiction is a disease characterized by profound disruptions in particular routes — or circuits — in the brain.

Scientists are learning how genetics and environmental factors, such as stress, contribute to these neural disruptions and increase the risk of addiction. This ongoing research is allowing researchers to:

  • Understand how addictive substances affect the brain’s reward system.
  • Develop more effective therapies for treating drug abuse and addiction.
  • Establish better methods of detecting people at risk of developing addictions.

Click here to read the complete article.

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April 19, 2011

Scientists find way to map brain’s complexity

From Reuters:

Scientists say they have moved a step closer to developing a computer model of the brain after finding a way to map both the connections and functions of nerve cells in the brain together for the first time.

In a study in the journal Nature on Sunday, researchers from Britain’s University College London (UCL) described a technique developed in mice which enabled them to combine information about the function of neurons with details of their connections.

The study is part of an emerging area of neuroscience research known as ‘connectomics‘. A little like genomics, which maps our genetic make-up, connectomics aims to map the brain’s connections, known as synapses.

By untangling and being able to map these connections — and deciphering how information flows through the brain’s circuits — scientists hope to understand how thoughts and perceptions are generated in the brain and how these functions go wrong in diseases such as Alzheimer’s, schizophrenia and stroke.

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April 18, 2011

Language and the Brain: What Makes Us Human

From Brain Briefings:

No other species on the planet uses language or writing — a mystery that remains unsolved even after thousands of years of research. Now neuroscientists are taking advantage of powerful new ways to peer into the brain to provide remarkable insights into this unique human ability.

Do you trip over your words, struggle to listen to a dinner companion in a noisy restaurant, or find it difficult to understand a foreign accent on TV? Help may be on the way. Using powerful new research tools, scientists have begun to unravel the long-standing mystery of how the human brain processes and understands speech.

In some ways, language is one of the oldest topics in human history, fascinating everyone from ancient philosophers to modern computer programmers. This is because language helps make us human. Although other animals communicate with one another, we are the only species to use complex speech and to record our messages through writing. This newly invigorated field, known as the neurobiology of language, helps scientists:

  • Gain important insights into the brain regions responsible for language comprehension.
  • Learn about underlying brain mechanisms that may cause speech and language disorders.
  • Understand the “cocktail party effect,” the ability to focus on specific voices against background noise.

Click here for the complete article.

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April 12, 2011

Using light to probe the brain’s self-repair after a stroke

Anne McIlroy of The Globe and Mail has written a nice article on how researchers are using optogenetics to study how the brain repairs itself after a stroke.

Click here to read the article.

Click here for videos on optogenetics.

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March 29, 2011

Being rejected a real pain, brain images show

From CBC News:

The pain of rejection is more than just a figure of speech: regions of the brain that respond to physical pain overlap with those that react to social rejection, a brain imaging study shows.

The study used brain imaging on people involved in romantic breakups.

“These results give new meaning to the idea that rejection ‘hurts,”‘ wrote psychology professor Ethan Kross of the University of Michigan and his colleagues. Their findings are reported in Tuesday’s edition of Proceedings of the National Academy of Sciences.

Co-author Edward Smith of Columbia University explained that the research shows that psychological or social events can affect regions of the brain that scientists thought were dedicated to physical pain.

Click here to read the rest of the article.

Click here for full access to the study published in Proceedings of the National Academy of Sciences.

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March 23, 2011

“I Am My Connectome”: TED Talk given by Sebastian Seung

In this TED talk Sebastian Seung, Professor of Computational Neuroscience in the Department of Brain and Cognitive Sciences and the Department of Physics at MIT, discusses the “connectome” – the connections formed between neurons – and its possible role in consciousness. Dr. Seung highlights neuroscientists’ belief that neural activity is the physical basis of thoughts, feelings and perceptions and discusses the relation between neural activity and the connectome: neural activity travels through a connectome, but at the same time, these connections can grow and be modified by neural activity and experience. As Dr. Seung put it “the connectome is where nature meets nurture”.

This is a TED talk (about 20 mins) you don’t want to miss! Click here to watch the talk.

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March 10, 2011

Can Someone in a Vegetative State Communicate Thoughts?

In this short video (about 4 mins) from the New York Times, David Corcoran discusses evidence from an fMRI study that suggests that people in a vegetative state can communicate thoughts.

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March 3, 2011

Interactive Video: Progression of Alzheimer’s in the Brain

Click here for an interactive video showing the progression of Alzheimer’s in the brain from the Globe and Mail.

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February 26, 2011

Cognitive Electrophysiology: Signals of the Mind

cognitive neuroscience,conferences — alice @ 1:38 pm

A Tribute to Steven A. Hillyard

A Satellite Symposium of the Cognitive Neuroscience Science Meeting
Saturday, April 2, 2011, Ballroom A, Hyatt Regency San Francisco

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February 23, 2011

Scientists look to new imaging techniques to measure metals in the brain

From the Globe and Mail:

We are metal heads. Our brains need iron, copper, manganese and zinc to function, yet there is growing evidence that these metals may play a role in Alzheimer’s disease, Parkinson’s disease multiple sclerosis and other illnesses.

Canadian scientists are developing new imaging techniques to accurately map and measure metals in the brain, a crucial step toward learning more about why they are so essential, as well as understanding the damage they can cause under some circumstances.

Click here to read the rest of the article.

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February 21, 2011

Former CFL players’ brains used to study link between concussions and disease

From the Globe and Mail:

Concussion stories from Bobby Kuntz’s days with the Toronto Argonauts and the Hamilton Tiger-Cats made for family football folklore until a decade ago when they suddenly seemed bittersweet.

Mr. Kuntz, who suffered as many as 20 concussions playing football in the 1950s and 60s, developed a tremor and started to forget things. His golf game went and he had to give up his position as president and chief executive officer of his family’s metal finishing business.

His symptoms were progressive, yet difficult to diagnose. His wife, Mary, took him down to the Mayo Clinic – he was in his late 60s – and doctors suggested Lewy Body dementia and Parkinson’s.

“The only way you’ll ever find out if its Lewy Body disease is to have an autopsy,” Mrs. Kuntz recalled the Mayo Clinic doctors telling her about a decade ago.

She had always planned on having her husband autopsied as she was concerned about whether her five living children were at risk of inheriting his brain disease. Ms. Kuntz wants to know if there is a link between repeated concussions and his Lewy Body disease, a progressive form of dementia, or Parkinson’s, a degenerative disorder of the central nervous system with similar characteristics.

Click here to read the rest of this article.

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February 19, 2011

How Brains Are Built: Principles of Computational Neuroscience

From The Dana Foundation:

Editor’s note: The goal of computational neuroscience is to understand the brain and its mechanisms well enough to artificially simulate their functions. In some areas, like hearing, vision, and prosthetics, there have been great advances in the field. Yet there is still much about the brain that is unknown and therefore cannot be artificially replicated: How does the brain use language, make complex associations, or organize learned experiences? Once the neural pathways responsible for these and many other functions are fully understood and reconstructed, researchers will have the ability to build systems that can match—and maybe even exceed—the brain’s capabilities.

“If I cannot build it, I do not understand it.” So said Nobel laureate Richard Feynman, and by his metric, we understand a bit about physics, less about chemistry, and almost nothing about biology.1

When we fully understand a phenomenon, we can specify its entire sequence of events, causes, and effects so completely that it is possible to fully simulate it, with all its internal mechanisms intact. Achieving that level of understanding is rare. It is commensurate with constructing a full design for a machine that could serve as a stand-in for the thing being studied.  To understand a phenomenon sufficiently to fully simulate it is to understand it computationally.

“Computation” does not refer to computers per se; rather it refers to the underlying principles and methods that make them work. As Turing Award recipient Edsger Dijkstra said, computational science “is no more about computers than astronomy is about telescopes.”2 Computational science is the study of the hidden rules underlying complex phenomena from physics to psychology.

Computational neuroscience, then, has the aim of understanding brains sufficiently well to be able to simulate their functions, thereby subsuming the twin goals of science and engineering: deeply understanding the inner workings of our brains, and being able to construct simulacra of them. As simple robots today substitute for human physical abilities, in settings from factories to hospitals, so brain engineering will construct stand-ins for our mental abilities—and possibly even enable us to fix our brains when they break.

Read the rest of the article.

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February 17, 2011

Emotional processing in anterior cingulate and medial prefrontal cortex

A. Etkinsend, T. Egner, R. Kalisch
Article in Trends in Cognitive Sciences

Abstract
Negative emotional stimuli activate a broad network of brain regions, including the medial prefrontal (mPFC) and anterior cingulate (ACC) cortices. An early influential view dichotomized these regions into dorsal–caudal cognitive and ventral–rostral affective subdivisions. In this review, we examine a wealth of recent research on negative emotions in animals and humans, using the example of fear or anxiety, and conclude that, contrary to the traditional dichotomy, both subdivisions make key contributions to emotional processing. Specifically, dorsal–caudal regions of the ACC and mPFC are involved in appraisal and expression of negative emotion, whereas ventral–rostral portions of the ACC and mPFC have a regulatory role with respect to limbic regions involved in generating emotional responses. Moreover, this new framework is broadly consistent with emerging data on other negative and positive emotions.

Click here for the full article.

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January 6, 2011

Consciousness and Cognition Journal: Table of Contents December 2010

The December issue of Consciousness and Cognition is available  online:

Volume 19, Issue 4, December 2010

Table of Contents:

REGULAR ARTICLES
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December 3, 2010

‘Consciousness signature’ discovered spanning the brain

From: Newscientist.com:   Electrodes implanted in the brains of people with epilepsy might have resolved an ancient question about consciousness.

Signals from the electrodes seem to show that consciousness arises from the coordinated activity of the entire brain. The signals also take us closer to finding an objective “consciousness signature” that could be used to probe the process in animals and people with brain damage without inserting electrodes.

Previously it wasn’t clear whether a dedicated brain area, or “seat of consciousness”, was responsible for guiding our subjective view of the world, or whether consciousness was the result of concerted activity across the whole brain.

Probing the process has been a challenge, as non-invasive techniques such as magnetic resonance imaging and EEG give either spatial or temporal information but not both. The best way to get both simultaneously is to implant electrodes deep inside the skull, but it is difficult to justify this in healthy people for ethical reasons.

Brainy opportunity

Now neuroscientist Raphaël Gaillard of INSERM in Gif sur Yvette, France, and colleagues have taken advantage of a unique opportunity. They have probed consciousness in 10 people who had intercranial electrodes implanted for treating drug-resistant epilepsy.

Click here for the entire article.

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November 11, 2010

What Makes You Uniquely You?

From: Discovermagazine.com

Feb 2009

Nobel laureate Gerald Edelman says your brain is one-of-a-kind in the history of the universe.

Some of the most profound questions in science are also the least tangible. What does it mean to be sentient? What is the self? When issues become imponderable, many researchers demur, but neuro­scientist Gerald Edelman dives right in.

A physician and cell biologist who won a 1972 Nobel Prize for his work describing the structure of antibodies, Edelman is now obsessed with the enigma of human consciousness—except that he does not see it as an enigma. In Edelman’s grand theory of the mind, consciousness is a biological phenomenon and the brain develops through a process similar to natural selection. Neurons proliferate and form connections in infancy; then experience weeds out the useless from the useful, molding the adult brain in sync with its environment.

Edelman first put this model on paper in the Zurich airport in 1977 as he was killing time waiting for a flight. Since then he has written eight books on the subject, the most recent being Second Nature: Brain Science and Human Knowledge. He is chairman of neurobiology at the Scripps Research Institute in San Diego and the founder and director of the Neurosciences Institute, a research center in La Jolla, California, dedicated to unconventional “high risk, high payoff” science.

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October 25, 2009

Theta Rhythm and Memory Performance

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.

Click here for the full paper.

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October 21, 2009

What Can Dance Teach Us about Learning?

cognitive neuroscience,memory — alice @ 9:19 pm

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.

Click here for the complete article.

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October 17, 2009

Alpha Oscillations, Attention and Consciousness

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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