March 10, 2011
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February 15, 2011
From The Dana Foundation:
Study the literature of the world and you will find one theme that transcends both time and culture: that of love. Whether you are reading Shakespeare or Rumi, the manner in which love is described shows remarkable similarity. Those similarities go far beyond the page: Neuroscientists are now demonstrating that romantic love is also represented by a unique pattern of activation in the brain.
The neuroimaging of love
In the past six years, several groups of researchers have sought to localize romantic love in the brain using functional magnetic resonance imaging (fMRI) techniques. Though some have criticized the attempt as nothing more than modern day phrenology, those who seek the neural correlates of love believe it an essential avenue of study.
“The study of love is important so we might bring some rationality to a complex and emotional phenomenon,” says Stephanie Ortigue, a neuroscientist at Syracuse University. “These studies allow scientists to show that love is not a drug or a pathology but something that has a unique signature in the healthy brain.”Read more... Comments (0)
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.Read more... Comments (0)
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.Read more... Comments (0)
January 31, 2009
Hyperactivity and Hyperconnectivity of the Default Network in Schizophrenia and in First-degree Relatives of Persons with Schizophrenia
Susan Whitfield-Gabrieli, Heidi W. Thermenos, Snezana Milanovic, Ming T. Tsuang, Stephen V. Faraone, Robert W. McCarley, Martha E. Shenton, Alan I. Green, Alfonso Nieto-Castanon, Peter LaViolette, Joanne Wojcik, John D. E. Gabrieli and Larry J. Seidman
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.
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January 12, 2008
Neuronal correlates of “free will” are associated with regional specialization in the human intrinsic/default network
December 11, 2007
The capacity of the human mind to believe or disbelieve a statement is a powerful force for controlling both behavior and emotion, but the basis of these states in the brain is not yet understood. A new study found that belief, disbelief and uncertainty activate distinct regions of the brain, with belief/disbelief affecting areas associated with the pleasantness/unpleasantness of tastes and odors. The study will publish online in the Annals of Neurology, the official journal of the American Neurological Association.
Led by Sam Harris of the University of California, Los Angeles, the study involved 14 adults who underwent functional MRI scans during which they were presented with short statements that they had to evaluate as true, false or undecided. Each participant underwent three scans while they evaluated statements from a broad variety of categories such as mathematical, geographical, autobiographical, religious and factual. The statements were designed to be clearly true, false or undecidable.
Contrasting belief and disbelief trials yielded increased signal in the (VMPFC), which is involved in linking factual knowledge with emotion. “The involvement of the VMPFC in belief processing suggests an anatomical link between the purely cognitive aspects of belief and human emotion and reward,” the authors state. The fact that ethical belief showed a similar pattern of activation to mathematical belief suggests that the physiological difference between belief and disbelief is not related to content or emotional associations, they note.Read more... Comments (0)
October 31, 2007
PLOS Biology has a most interesting article from Stanislas Dehaene‘s group on the neurodynamics of conscious experience. The researchers studied brain activation using EEG, while subjects rated visually presented stimuli on a scale from unseen to clearly seen. It was found that conscious experience of a stimulus was related to the engagement of a widespread network involving the frontal, parietal and temporal cortices.
SCR note: It is mentioning a recent study using fMRI (Christensen et al. 2006) provided comparable results, and adding two factors; (1) the conscious experience of a visual stimulus involved activation of both thalami, and (2) subjects consistently rated some experiences as vague, i.e., as “detected but not identified”. This experience was associated with both lower activation in those regions involved in conscious experience, and unique activation of additional regions, including some prefrontal regions.Read more... Comments (2)
August 2, 2007
May 24, 2007
Amanda lies flat on her back, clad in a steel blue hospital gown and an air of anticipation, as she is rolled headfirst into a beeping, 10-ton functional magnetic resonance imaging (fMRI) unit. Once inside, the 20-something blonde uses a handheld device to respond to questions about the playing cards appearing on the screen at the foot of the machine. With each click of the button, she is either lying or telling the truth about whether a card presented to her matches the one in her pocket, and the white-coated technician who watches her brain image morph into patterns on his computer screen seems to know the difference.
It’s unlikely anyone would shell out $10,000 to exonerate herself in a dispute over gin rummy. But Amanda, the model in a demo video for Tarzana, Calif.-based No Lie MRI, is helping to make a point: lie-detection is going high-tech. No Lie MRI claims it can identify lies with 90% accuracy. The service is meant for “anybody who wants to demonstrate that they are telling truth to others,” says founder and CEO Joel Huizenga. “Everyone should be allowed to use whatever method they can to defend themselves.Read more... Comments (0)
May 22, 2007
What is the nature of thought? And what is the resting state? Moshe Bar and colleagues argues in a new paper (PDF) in the journal Hippocampus that besides the long-held idea that associative processing provides the vehicle of thought, that “one primary outcome of associative processing is the generation of predictions, which approximate the immediately relevant future and thus facilitate perception, action, and the progression of thought”.
From the article:
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Nature has an interesting report from Marc Raichle‘s laboratory that studies the resting states in monkeys. This study not only demonstrates that resting states occur in non-human primates, but that it is possible to find such activity during unconscious states.
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.Read more... Comments (0)
March 7, 2007
In case you didn’t hear about it there are recent claims that brain scanners can predict people’s action before they act. Here is a report from Associated Press.
At a laboratory in Germany, volunteers slide into a donut-shaped MRI machine and perform simple tasks, such as deciding whether to add or subtract two numbers, or choosing which of two buttons to press. They have no inkling that scientists in the next room are trying to read their minds – using a brain scan to figure out their intention before it is turned into action.Read more... Comments (4)
February 8, 2007
Pain is one of the most prominent examples of the problem of consciousness: from a subjective point of view we know the experience of pain all too well. Seen from the objective side of pain, the neural processes related to pain are becoming unravelled. But the essential relationship between neural processes going on from the sensation to the experience are much less known.
In a study by Christmann and colleagues, a combination of EEG and fMRI demonstrates how regional brain areas make different contributions — and at different times — to the experience of pain.Read more... Comments (1)
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.Read more... Comments (1)
January 17, 2007
In this protocol we describe how to perform the Multi-Source Interference Task (MSIT), a validated functional magnetic resonance imaging (fMRI) task that reliably and robustly activates the cingulo-frontal-parietal cognitive/attention network (CFP network) within individual subjects. The MSIT can be used to (i) identify the cognitive/attention network in normal volunteers and (ii) test its integrity in people with neuropsychiatric disorders. It is simple to perform, can be completed in less than 15 min and is not language specific, making it appropriate for children, adults and the elderly. Since its validation, over 100 adults have performed the task. The MSIT produces a robust and temporally stable reaction time interference effect (range 200–350 ms), and single runs of the MSIT have produced CFP network activation in approximately 95% of tested subjects. The robust, reliable and temporally stable neuroimaging and performance data make the MSIT a useful task with which to study normal human cognition and psychiatric pathophysiology.Read more... Comments (0)
December 31, 2006
Are conscious and nonconscious processes supported by overlapping brain regions? In a recent study, Slotnick and Schacter investigated whether activity, related to visual memory, in early visual regions (BA17 and BA18) is reflective of nonconscious processing. The results of their study suggest that early visual regions (BA17, BA18) are associated with nonconcsious memory, while late visual regions (BA19, BA37) are associated with conscious memory. Click through for abstract. Hubmed.Read more... Comments (0)
December 21, 2006
Steven Laureys and colleagues ask whether functional imaging methods such as fMRI and PET can be used to detect consciousness in individual patients. Recent studies have showed activation patterns in a vegetative patient that are comparable to helahty subjects. One pertinent question is therefore whether we can move from group studies towards individual scans. Here, Laureys et al. still have reservations, saying that “[published] data are insufficient to make recommendations for or against any of the neurorehabilitative treatments in vegetative state and minimally conscious state patients.”
How should functional imaging of patients with disorders of consciousness contribute to their clinical rehabilitation needs? Laureys S, Giacino JT, Schiff ND, Schabus M, Owen AM. 2006 Dec ; 19 (6): 520-527Read more... Comments (0)
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