February 2, 2011

Brain Waves and Meditation

From: ScienceDaily.com

Forget about crystals and candles, and about sitting and breathing in awkward ways. Meditation research explores how the brain works when we refrain from concentration, rumination and intentional thinking. Electrical brain waves suggest that mental activity during meditation is wakeful and relaxed.

“Given the popularity and effectiveness of meditation as a means of alleviating stress and maintaining good health, there is a pressing need for a rigorous investigation of how it affects brain function,” says Professor Jim Lagopoulos of Sydney University, Australia. Lagopoulos is the principal investigator of a joint study between his university and researchers from the Norwegian University of Science and Technology (NTNU) on changes in electrical brain activity during nondirective meditation.

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January 18, 2011

Sizing Up Consciousness by Its Bits

From: NYTimes.com

One day in 2007, Dr. Giulio Tononi lay on a hospital stretcher as an anesthesiologist prepared him for surgery. For Dr. Tononi, it was a moment of intellectual exhilaration. He is a distinguished chair in consciousness science at the University of Wisconsin, and for much of his life he has been developing a theory of consciousness. Lying in the hospital, Dr. Tononi finally had a chance to become his own experiment.

The anesthesiologist was preparing to give Dr. Tononi one drug to render him unconscious, and another one to block muscle movements. Dr. Tononi suggested the anesthesiologist first tie a band around his arm to keep out the muscle-blocking drug. The anesthesiologist could then ask Dr. Tononi to lift his finger from time to time, so they could mark the moment he lost awareness.
The anesthesiologist did not share Dr. Tononi’s excitement. “He could not have been less interested,” Dr. Tononi recalled. “He just said, ‘Yes, yes, yes,’ and put me to sleep. He was thinking, ‘This guy must be out of his mind.’ ”

Dr. Tononi was not offended. Consciousness has long been the province of philosophers, and most doctors steer clear of their abstract speculations. After all, debating the finer points of what it is like to be a brain floating in a vat does not tell you how much anesthetic to give a patient.

But Dr. Tononi’s theory is, potentially, very different. He and his colleagues are translating the poetry of our conscious experiences into the precise language of mathematics.

To do so, they are adapting information theory, a branch of science originally applied to computers and telecommunications. If Dr. Tononi is right, he and his colleagues may be able to build a “consciousness meter” that doctors can use to measure consciousness as easily as they measure blood pressure and body temperature. Perhaps then his anesthesiologist will become interested.

“I love his ideas,” said Christof Koch, an expert on consciousness at Caltech. “It’s the only really promising fundamental theory of consciousness.”

Sizing Up Consciousness by its Bits: Read the entire article

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January 13, 2011

“Erasing” Traumatic Memories Moving from Science Fiction to Scientific Reality

From: TheGlobeandMail.com

The brain has a remarkable capacity for keeping track of our past experiences. But detailed memories can sometimes seem more a curse than a blessing. This is especially true for those who’ve suffered significant losses or other traumas. Thus, while the holiday season is meant to be a joyous time, for many it merely provides salient reminders of these debilitating experiences.

Fortunately, researchers are discovering that memories may be far less durable than previously thought. Indeed research on “erasing” traumatic memories is quickly moving from the realm of science fiction to scientifically backed reality.

That each of us may be able to exert some control over what gets in and what then stays in long-term memory arises from our growing understanding of how the brain represents and stores information related to our conscious life experiences.

Read the entire article: “Erasing” Traumatic Memories Moving from Science Fiction to Scientific Reality

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January 11, 2011

Neuroscientist, VS Ramachandran: The neurons that Shaped Civilization

Enjoy this short video:

From: Ted.com

Neuroscientist Vilayanur Ramachandran outlines the fascinating functions of mirror neurons. Only recently discovered, these neurons allow us to learn complex social behaviors, some of which formed the foundations of human civilization as we know it.

Comments:

Hans Bauer

Jun 24 2010: Any species of comparable level in evolution may attain mirror neurons or something equivalent one day. May even be that this is already happening without our notice. It will hardly happen within a few days. As we heard it took hundreds of thousands of years for us.

May be that some species will develop culture and civilization one day – that is if mankind will not interfere.

By the way – my tom cat sometimes pees standing on two legs. Who knows how he learned it? :)

Watch the video, and read more

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December 23, 2010

A Prescription for Abdominal Pain: Due Diligence

From: NYTimes.com: “For some reason people respect headaches,” said Dr. Carlo Di Lorenzo, a leading pediatric gastroenterologist and a professor of clinical pediatrics at Ohio State. “I’ve never seen a parent or a pediatrician tell a child complaining of a headache, ‘You don’t have a headache — it’s not real.’ Bellyache is just as real as headache.”

Indeed it is. And recurrent abdominal pain in children is common, frustrating and often hard to explain.

Consider a girl who came to the clinic for her 10-year physical exam. She gets these bellyaches, she told me. Had a bad one that week, but her stomach wasn’t hurting right at the moment.

She’d been treated for constipation; she’d been tested for celiac disease and other problems. Every blood and stool test over the two years since the pain began was completely normal. One night the bellyache was so bad she went to the emergency room — and her abdominal X-rays were normal as well.

The diagnostic term for this common and perplexing condition is “functional abdominal pain”: recurrent stomachaches, as the American Academy of Pediatrics put it in 2005, with no “anatomic, metabolic, infectious, inflammatory or neoplastic disorder” to explain them.

When I was a resident, we often smirked when we spoke of functional abdominal pain, treating it as a code for a troublesome patient, dubious symptoms or an anxious family. But recent research suggests we were too biomedically narrow in our thinking.

Scientists are coming to understand that abdominal pain is transmitted by a specialized nervous system that may be hypersensitive or hyperactive in some children. Studies in which researchers inflated balloons in children’s intestines suggested that those with functional abdominal pain might be unusually sensitive to any distension on the inside.

Click here for the entire article

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December 7, 2010

The Same Old Consciousness

From: ErvinLaszlo.com:  It makes sense to paraphrase Einstein’s famous dictum in regard to consciousness. Our problem is the unsustainability of the world we have created, and we should be clear that we can’t solve this problem with the same kind of consciousness that gave rise to it.

But many people try to do just that, even the leaders of the world’s twenty richest and most powerful nations. The November 2010 meeting of the G20 in Seoul gave indisputable proof of it. Not only did the meeting fail to achieve its main objectives (among them rebalancing international trade and reaching an accommodation between the U.S. and South Korea), the objectives themselves proved to be out-of-date. They centered on re-stabilizing the same moribund economic and financial system that made the world unsustainable in the first place.

But why is the G20’s failure due to wrong consciousness? Because consciousness in the social, political, and cultural context is sum total of our view of the world, with its values, aspirations, and background assumptions. It’s the “paradigm” that underlies the way we think and the way we set our priorities. The consciousness of the G20 gives rise to an obsolete view of the world, with faulty values and outdated aspirations. The leaders view the world as the arena for a Darwinian struggle for survival, seen as a competition for growth in the economies of nations. Since assured growth cannot be achieved even by the wealthiest and most powerful nation in the world by itself, the leaders recognize the need for some level and form of cooperation—as a means to an end. The end is for the rich nations to make sure that they remain rich.

Click here for the complete article.

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November 6, 2010

Long-term Memories The Good, the Bad, and the Ugly

From The Dana Foundation

Editor’s note: Traumatic memories haunt the lives of people suffering from post-traumatic stress disorder, or PTSD, and other illnesses. Fortunately, recent research into the changeability of long-term memories may someday develop into treatments for such individuals. But before this can happen, writes Cristina Alberini, Ph.D., of Mount Sinai School of Medicine, researchers must determine just how effectively the fear associated with older memories—especially those involved in PTSD—can be reduced and for how long. Researchers must also address the ethical issues that go hand in hand with modifying memory.

For more than a century, clinicians, psychologists, and biologists have worked to understand the mechanisms underlying the formation and storage of long-term memories. Recently, scientists found that when a stored memory is recalled, it becomes sensitive to disruption for a limited time.1,2 This finding indicates that it might be possible to weaken or even erase memories of traumatic experiences that become uncontrollably intrusive in post-traumatic stress disorder (PTSD). This possibility has drawn great interest from scientific and clinical communities, as well as from nonscientists, who became interested in its potential clinical applications; furthermore, it raised ethical concerns.

Many ethical questions and debates about treatments designed to weaken memories may reflect the still poor understanding of how memory recall or reactivation results in memory fragility and the many unknowns surrounding its temporal boundaries. Whereas the study of animal models and healthy humans has provided some knowledge about post-recall memory disruption, data on the use of such disruption to treat PTSD symptoms are still conflicting. The strengthening of memory with the passage of time, the resilience of strong memories to disruption, and the specific aspects of memory that become sensitive to disruption raise questions about the limitations of this approach and warrant more research. Here, we will look at how we form memories of an emotional event and how these memories become fragile after recall. That will help us consider the potential, limitations, and ethics of disrupting memories of emotion.

Read the entire 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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October 5, 2009

Causal role of prefrontal cortex in the threshold for access to consciousness

attention,brain injury,perception — alice @ 12:36 am

A. Del Cul, S. Dehaene, P. Reyes, E. Bravo, A. Slachevsky
Article in Brain

Abstract
What neural mechanisms support our conscious perception of briefly presented stimuli? Some theories of conscious access postulate a key role of topdown amplification loops involving prefrontal cortex (PFC). To test this issue, we measured the visual backward masking threshold in patients with focal prefrontal lesions, using both objective and subjective measures while controlling for putative attention deficits. In all conditions of temporal or spatial attention cueing, the threshold for access to consciousness was systematically shifted in patients, particular after a lesion of the left anterior PFC. The deficit affected subjective reports more than objective performance, and objective performance conditioned on subjective visibility was essentially normal. We conclude that PFC makes a causal contribution to conscious visual perception of masked stimuli, and outline a dual-route signal detection theory of objective and subjective decision making.

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February 9, 2009

Interoceptive Awareness in Experienced Meditators

cognition,meditation,perception — alice @ 2:39 am

Meditation can be conceptualized as a complex form of attentional and emotional training that promotes well-being and emotional balance.  In most meditation traditions, a common practice is to focus one’s attention to internal body sensations, and many traditions state that this practice results in an increased awareness of internal body sensations.  In a study by Khalsa and colleagues, two groups of meditators (Tibetan Buddhist and Kundalini) were compared to a group of nonmeditators on their ability to detect their own heartbeat.  (The meditators and nonmeditators were matched for age and body mass index.)  Although the investigators predicted that the experienced meditators would outperform the nonmeditators, no such evidence was found.  Compared to the nonmeditators, however, the experienced meditators consistently rated the difficulty of the heartbeat detection task as easier and their interoceptive performance as superior.  These results suggest that the practice of focusing one’s attention to internal body sensations (a core feature of meditation) does not enhance the ability to sense the heartbeat at rest, but it alters the subjective experience of it.

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November 24, 2008

Real-time chemical responses in the nucleus accumbens differentiate rewarding and aversive stimuli

neurochemistry,neuroscience,perception — alice @ 1:28 am

Mitchell F Roitman, Robert A Wheeler, R Mark Wightman and Regina M Carelli
Article in Nature Neuroscience

Abstract
Rewarding and aversive stimuli evoke very different patterns of behavior and are rapidly discriminated. Here taste stimuli of opposite hedonic valence evoked opposite patterns of dopamine and metabolic activity within milliseconds in the nucleus accumbens. This rapid encoding may serve to guide ongoing behavioral responses and promote plastic changes in underlying circuitry.

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November 2, 2008

Art Teams With Science to Explain It All to You

attention,perception — alice @ 11:53 pm

From NY Times (Oct 31, 2008):  The taste of a ripe tomato, the hook of a catchy song, the scent of a lover’s hair. What is it, exactly, that drives us to seek these things again and again?

Neuroscientists who study perception are starting to discover the inner workings of the sensory mind. Starting on Monday at the New York Academy of Sciences, researchers and artists will team up to explore this new research in a series of talks called Science of the Five Senses. Their conversations will raise a question for the amateur hedonist: If we had a better understanding of the signals our bodies send to our brains, might we take more pleasure from them? 

Click here for complete article.

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Theta phase synchrony and conscious target perception: Impact of intensive mental training

Heleen A. Slagter, Antoine Lutz, Lawrence L. Greischar, Sander Nieuwenhuis, and Richard J. Davidson.
Article in Journal of Cognitive Neuroscience

Abstract
The information processing capacity of the human mind is limited, as is evidenced by the attentional blink-a deficit in identifying the second of two targets (T1 and T2) presented in close succession. This deficit is thought to result from an overinvestment of limited resources in T1 processing. We previously reported that intensive mental training in a style of meditation aimed at reducing elaborate object processing, reduced brain resource allocation to T1, and improved T2 accuracy [Slagter, H. A., Lutz, A., Greisschar, L. L., Frances, A. D., Nieuwenhuis, S., Davis, J., et al. Mental training affects distribution of limited brain resources. PloS Biology, 5, e138, 2007]. Here we report EEG spectral analyses to examine the possibility that this reduction in elaborate T1 processing rendered the system more available to process new target information, as indexed by T2-locked phase variability. Intensive mental training was associated with decreased cross-trial variability in the phase of oscillatory theta activity after successfully detected T2s, in particular, for those individuals who showed the greatest reduction in brain resource allocation to T1. These data implicate theta phase locking in conscious target perception, and suggest that after mental training the cognitive system is more rapidly available to process new target information. Mental training was not associated with changes in the amplitude of T2-induced responses or oscillatory activity before task onset. In combination, these findings illustrate the usefulness of systematic mental training in the study of the human mind by revealing the neural mechanisms that enable the brain to successfully represent target information.

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March 5, 2008

Neuropsychologia special issue: Consciousness & Perception

Neuropsychologia hosts a special issue in relation to the work of Larry Weiskrantz. It contains a densely packed number of articles on the topic of blindsight and hindsights.

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January 4, 2008

Decision making, impulsivity and time perception

Time is an important dimension when individuals make decisions. Specifically, the time until a beneficial outcome can be received is viewed as a cost and is weighed against the benefits of the outcome.

We propose that impulsive individuals experience time differently, that is with a higher cost. Impulsive subjects, therefore, overestimate the duration of time intervals and, as a consequence, discount the value of delayed rewards more strongly than do self-controlled individuals.

The literature on time perception and impulsivity, however, is not clear cut and needs a better theoretical foundation. Here, we develop the theoretical background on concepts of time perception, which could lead to an empirically based notion of the association between an altered sense of time and impulsivity.

Article by Marc Wittmann and Martin P. Paulus in Trends in Cognitive Sciences, Volume 12, Issue 1, January 2008, Pages 13-16

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December 10, 2007

Researchers can read thoughts to decipher what a person is actually seeing

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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Subliminal smells bias perception about a person’s likeability

From physorg.com — Anyone who has bonded with a puppy madly sniffing with affection gets an idea of how scents, most not apparent to humans, are critical to a dog’s appreciation of her two-legged friends. Now new research from Northwestern University suggests that humans also pick up infinitesimal scents that affect whether or not we like somebody. “We evaluate people every day and make judgments about who we like or don’t like,” said Wen Li, a post-doctoral fellow in the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern’s Feinberg School of Medicine and lead author of the study. “We may think our judgments are based only on various conscious bits of information, but our senses also may provide subliminal perceptual information that affects our behavior.”

“Subliminal Smells Can Guide Social Preferences” was published in the December issue of Psychological Science. Besides Li, the
study’s co-investigators include Isabel Moallem, Loyola University; Ken Paller, professor of psychology in the Weinberg College of Arts and Sciences at Northwestern; and Jay Gottfried, assistant professor of neurology at Feinberg and senior author of the paper.

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December 7, 2007

How emotions colour our perception of time

emotions,perception — thomasr @ 6:39 am

Our sense of time is altered by our emotions to such an extent that time seems to fly when we are having fun and drags when we are bored. Recent studies using standardized emotional material provide a unique opportunity for understanding the neurocognitive mechanisms that underlie the effects of emotion on timing and time perception in the milliseconds-to-hours range.

We outline how these new findings can be explained within the framework of internal-clock models and describe how emotional arousal and valence interact to produce both increases and decreases in attentional time sharing and clock speed. The study of time and emotion is at a crossroads, and we outline possible examples for future directions

Article by Sylvie Droit-Volet & Warren H. Meck in Trends in Cognitive Sciences, Volume 11, Issue 12, December 2007, Pages 504-513

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November 10, 2007

Distance changes face perception?

illusion,perception,social psychology — thomasr @ 4:14 am

Illusion%20image.jpgThis is  probably one of the best illusions ever! Please do the following: look at the above images from your seat in front of the computer; Mr. Angry is on the left, and Ms.Calm is on the right. Now, get up from your seat, and move back 10 or 12 feet. Who’s the angry and calm now?

 

It’s said that this illusion was made by Phillippe G.Schyns and Aude Oliva. Cudos to Robert Karl Stonjek for showing us this illusion.

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October 31, 2007

Psychic studies may be influenced by suggestion:

altered states,introspection,perception — thomasr @ 4:26 am

From Mind hacks: The BPS Research Digest has discussed a recent study that analysed recordings of parapsychology experiments and has found that some of the positive findings may be due to experimenters unconsciously prompting the participants as they gave their answers.The experiments used the Ganzfeld technique where one participant has diffuse white light and auditory noise played to them, effectively blocking the key senses, while another tries to ‘send’ images to them through mental projection.

Afterwards, the ‘receiver’ tells the experimenter what images came to mind and the research team see if it matches what the ‘sender’ was trying to transmit.

Taken as a whole, these sorts of experiments show a weak but positive evidence for extra-sensory perception (ESP), but it’s not clear whether this isn’t just due to a tendency for some negative trials not being reported.

In this new study, psychologist Robin Woofit analysed the tapes of Ganzfeld experiments from the mid-1990s and found that experimenters were more likely to respond decisively to correct responses but give subtle cues (such as saying ‘mm hm’) to give more information when the response wasn’t initially accurate.

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