A silver dollar-sized region deep in the brain called the insula is intimately involved in smoking addiction, and damage to this structure can completely erase the body's urge to smoke, researchers have discovered. The findings appear in the 26 January 2007 issue of the journal Science, published by AAAS, the nonprofit science society.
Obviously brain damage is not a treatment option for nicotine addiction, but the new results may offer leads for therapies to help smokers kick the habit or for monitoring smokers' progress while using existing therapies.
The study was largely inspired by a patient who had smoked around 40 cigarettes a day before his insula was damaged by a stroke and then quit immediately after. He told the researchers that his body "forgot the urge to smoke." [read more]
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Saturday, January 27
by
Dr. A
on Sat 27 Jan 2007 10:20 AM CST
Friday, January 19
by
Dr. A
on Fri 19 Jan 2007 08:12 PM CST
Many people think they can safely drive while talking on their cell phones. Vanderbilt neuroscientists Paul E. Dux and René Marois have found that when it comes to handling two things at once, your brain, while fast, isn't that fast.
"Why is it that with our incredibly complex and sophisticated brain, with 100 billion neurons processing information at rates of up to a thousand times a second, we still have such a crippling inability to do two tasks at once?" Marois, associate professor of Psychology, asked. "For example, what is it about our brain that gives us such a hard time at being able to drive and talk on a cell phone simultaneously?" Researchers have long thought that a central "bottleneck" exists in the brain that prevents us from doing two things at once. Dux and Marois are the first to identify the regions of the brain responsible for this bottleneck, by examining patterns of neural activity over time. Their results were published in the Dec. 21 issue of Neuron. "In our everyday lives, we seem to complete so many cognitive tasks effortlessly. However, we experience severe limitations when we try to do even two simple tasks at once, such as pressing a button when a visual stimulus appears and saying a word when a sound is presented. This is known as dual-task interference," Dux, a postdoctoral research associate in the Department of Psychology, said. "We were interested in trying to understand these limitations and in finding where in the brain this bottleneck might be taking place." The research is particularly timely, as additional states consider banning the use of cell phones while driving. "While we are driving, we are bombarded with visual information. We might also be talking to passengers or talking on the phone," Marois said. "Our new research offers neurological evidence that the brain cannot effectively do two things at once. People think if they are using a headset with their cell phone while driving they are safe, but they're not because they are still doing two cognitively demanding tasks at once." Identifying the information bottleneck responsible for this dual-task limitation required the use of functional magnetic resonance imaging, or fMRI, an imaging technology that reveals the brain areas active in a given mental task by registering changes in oxygenated blood concentration in these regions. While fMRI is an excellent tool for identifying a particular area in the brain involved in a given task, it generally provides limited information about how that area responds over time. To overcome this limitation, Dux and Marois rapidly sampled brain activity using fMRI while subjects were performing two demanding tasks. Evaluation of the data produced by this rapid sampling method allowed them to characterize the temporal pattern of activity in specific brain areas. The two tasks consisted of pressing the appropriate computer key in response to hearing one of eight possible sounds and uttering an appropriate syllable in response to seeing one of eight possible images. Different senses and motor responses were enlisted in order to ensure that any interference between the two tasks was not specific to a particular sensory or motor modality, but instead originated at a central information-processing bottleneck. The results revealed that the central bottleneck was caused by the inability of the lateral frontal and prefrontal cortex, and also the superior frontal cortex, to process the two tasks at once. Both areas have been shown in previous experiments to play a critical role in cognitive control. "We determined these brain regions responded to tasks irrespective of the senses involved, they were engaged in selecting the appropriate response, and, most importantly, they showed 'queing' of neural activity--the neural response to the second task was postponed until the response to the first was completed," Dux said. "Neural activity seemed to be delayed for the second task when the two tasks were presented nearly simultaneously – within 300 milliseconds of each other," Marois said. "If individuals have a second or more between tasks, we did not see this delay. "This temporal delay is the essence of dual-task interference for tasks that require actions. By using time-resolved fMRI, we can see its signature in the brain," he continued. "These findings allow us to really now focus on this set of brain areas and to understand why these areas cannot process two tasks at once." The researchers are interested in further exploring what is happening in the bottleneck to slow performance and believe the work may have future implications for people performing complex tasks. "It may be possible to look to the sort of tasks people are going to have to do in a very complex environment, such as flying a plane, and find out under what circumstances these tasks may be less vulnerable to dual-task interference," Dux added. For the record, neither Marois nor Dux use their cell phones while driving. "I'm Australian, and it's illegal there, so I'm trained not to," Dux said. "Even so, I would never do it. Dual-task costs can be up to a second, and that's a long time when you're traveling at 60 miles per hour."
by
Dr. A
on Fri 19 Jan 2007 10:56 AM CST
Up to one in three mental health patients are being over-prescribed drugs, says the Healthcare Commission [in Great Britain]. Read the article.
Ditto for the U.S.
by
Dr. A
on Fri 19 Jan 2007 10:51 AM CST
Why Does Cognitive Therapy Work?
By James Krehbiel Wednesday, January 17
by
Dr. A
on Wed 17 Jan 2007 11:17 AM CST
WASHINGTON, D.C. and LONDON, ENGLAND - January 17, 2006 -- The Bulletin of the Atomic Scientists (BAS) is moving the minute hand of the Doomsday Clock today from seven to five minutes to midnight. Reflecting global failures to solve the problems posed by nuclear weapons and the climate crisis, the decision by the BAS Board of Directors was made in consultation with the Bulletin's Board of Sponsors, which includes 18 Nobel Laureates.
BAS announced the Clock change today at an unprecedented joint news conference held at the American Association for the Advancement of Science in Washington, DC, and the Royal Society in London. In a statement supporting the decision to move the hand of the Doomsday Clock, the BAS Board focused on two major sources of catastrophe: the perils of 27,000 nuclear weapons, 2000 of them ready to launch within minutes; and the destruction of human habitats from climate change. In articles by 14 leading scientists and security experts writing in the January-February issue of the Bulletin of the Atomic Scientists (http://www.thebulletin.org), the potential for catastrophic damage from human-made technologies is explored further. Created in 1947 by the Bulletin of the Atomic Scientists, the Doomsday Clock has been adjusted only 17 times prior to today, most recently in February 2002 after the events of 9/11. By moving the hand of the Clock closer to midnight--the figurative end of civilization--the BAS Board of Directors is drawing attention to the increasing dangers from the spread of nuclear weapons in a world of violent conflict, and to the catastrophic harm from climate change that is unfolding. The BAS statement explains: "We stand at the brink of a Second Nuclear Age. Not since the first atomic bombs were dropped on Hiroshima and Nagasaki has the world faced such perilous choices. North Korea's recent test of a nuclear weapon, Iran's nuclear ambitions, a renewed emphasis on the military utility of nuclear weapons, the failure to adequately secure nuclear materials, and the continued presence of some 26,000 nuclear weapons in the United States and Russia are symptomatic of a failure to solve the problems posed by the most destructive technology on Earth." The BAS statement continues: "The dangers posed by climate change are nearly as dire as those posed by nuclear weapons. The effects may be less dramatic in the short term than the destruction that could be wrought by nuclear explosions, but over the next three to four decades climate change could cause irremediable harm to the habitats upon which human societies depend for survival." Stephen Hawking, a BAS sponsor, professor of mathematics at the University of Cambridge, and a fellow of The Royal Society, said: "As scientists, we understand the dangers of nuclear weapons and their devastating effects, and we are learning how human activities and technologies are affecting climate systems in ways that may forever change life on Earth. As citizens of the world, we have a duty to alert the public to the unnecessary risks that we live with every day, and to the perils we foresee if governments and societies do not take action now to render nuclear weapons obsolete and to prevent further climate change." Kennette Benedict, executive director, Bulletin of the Atomic Scientists, said: "As we stand at the brink of a Second Nuclear Age and at the onset of unprecedented climate change, our way of thinking about the uses and control of technologies must change to prevent unspeakable destruction and future human suffering." Sir Martin Rees, president of the Royal Society, professor of cosmology and astrophysics, master of Trinity College at the University of Cambridge, and a BAS sponsor, said: "Nuclear weapons still pose the most catastrophic and immediate threat to humanity, but climate change and emerging technologies in the life sciences also have the potential to end civilization as we know it." Lawrence M. Krauss, professor of physics and astronomy at Case Western Reserve University, and a BAS sponsor, said: "In these dangerous times, scientists have a responsibility to speak truth to power especially if it might provoke actions to reduce threats from the preventable technological dangers currently facing humanity. To do anything else would be negligent." Ambassador Thomas Pickering, a BAS director and co-chair of the International Crisis Group, said: "Although our current situation is dire, we have the means today to successfully address these global problems. For example, through vigorous diplomacy and international agencies like the International Atomic Energy Agency, we can negotiate and implement agreements that could protect us all from the most destructive technology on Earth--nuclear weapons." Additional information is available on the Web at http://www.thebulletin.org. Thursday, January 11
by
Dr. A
on Thu 11 Jan 2007 10:51 AM CST
Research into procrastination shows surprising findings
A University of Calgary professor in the Haskayne School of Business has recently published his magnum opus on the subject of procrastination – and it's only taken him 10 years. Joking aside, Dr. Piers Steel is probably the world's foremost expert on the subject of putting off until tomorrow what should be done today. His comprehensive analysis of procrastination research, published in the recent edition of the American Psychological Association's Psychological Bulletin, presents some surprising conclusions on the subject, such as: * Most people's New Year's resolutions are doomed to failure * Most self-help books have it completely wrong when they say perfectionism is at the root of procrastination, and * Procrastination can be explained by a single mathematical equation "Essentially, procrastinators have less confidence in themselves, less expectancy that they can actually complete a task," Steel says. "Perfectionism is not the culprit. In fact, perfectionists actually procrastinate less, but they worry about it more." Other predictors of procrastination include: task aversiveness, impulsiveness, distractibility, and how much a person is motivated to achieve. Not all delays can be considered procrastination; the key is that a person must believe it would be better to start working on given tasks immediately, but still not start. It's estimated that about 15-20 per cent of the general population are procrastinators. And the costs of procrastinating can add up well beyond poor work performance, especially for those who delay filing their taxes or planning their retirement. Steel says motivational failures such as difficulty in sticking to diets and exercise regimes – frequently the focus of New Year's resolutions – are related to procrastination because impulsiveness is often at the root of the failure. "Temptations that are close at hand are difficult to resist. Addicts often relapse after returning from treatment facilities because drugs and alcohol become easily available and daily habits reassert themselves. Or we load up on bread in the restaurant before the meal is served. Or we check our email 10 times an hour instead of completing a project." The good news is that willpower has an unusual capacity. "The old saying is true: 'Whether you believe you can or believe you can't, you're probably right'," Steel says. "And as you get better at self control, your expectancy about whether you can resist goes up and thus improves your ability to resist." Steel has also come up with the E=MC2 of procrastination, a formula he's dubbed Temporal Motivational Theory, which takes into account factors such as the expectancy a person has of succeeding with a given task (E), the value of completing the task (V), the desirability of the task (Utility), its immediacy or availability (Ã) and the person's sensitivity to delay (D). It looks like this and uses the Greek letter Ã: Utility = E x V/ÃD It's still unclear why some people may be more prone to developing procrastination behaviour, but some evidence suggests it may be genetic. Steel concludes: "Continued research into procrastination should not be delayed, especially because its prevalence seems to be growing." Tuesday, January 2
by
Dr. A
on Tue 02 Jan 2007 07:13 PM CST
People who were abused and neglected during childhood have a higher risk of major depression when they become young adults, according to a report in the January issue of the Archives of General Psychiatry, one of the JAMA/Archives journals.
Child abuse has been linked to depression in clinical populations and community surveys, according to background information in the article. But few prospective longitudinal studies have examined the relationship between abuse or neglect in childhood and depression in adulthood. Cathy Spatz Widom, Ph.D., then of the New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, and now of John Jay College of Criminal Justice, New York, and colleagues conducted a prospective study to determine whether abused and neglected children were at elevated risk of major depressive disorder (MDD) and psychiatric illness, compared with matched control subjects, when followed up into young adulthood. The study included 676 children with substantiated cases of physical and sexual abuse and neglect before the age of 11. They were matched based on age, race, sex, and approximate family social class with 520 non-abused and non-neglected children. All were followed up into young adulthood (average age: 28.7). "The current results show that childhood physical abuse was associated with increased risk for lifetime MDD," the authors write. "We also provide new evidence that neglected children are at increased risk for depression as well." Child abuse and neglect were associated with a 51 percent increased risk for current MDD in young adulthood. Children who were physically abused had a 59 percent increased risk of lifetime MDD. Those who experienced multiple types of abuse had a 75 percent increased risk of lifetime MDD. The risk of current MDD was 59 percent higher for those who were neglected. Childhood sexual abuse was not associated with an elevated risk of MDD. "However, childhood victims of sexual abuse reported significantly more depression symptoms than controls," the authors point out. "In addition, these findings reveal that onset of depression began in childhood for many of the children," they write. "Our age-at-onset findings reinforce the need to intervene early in the lives of these abused and neglected children, before depression symptoms cascade into other spheres of functioning."
by
Dr. A
on Tue 02 Jan 2007 08:44 AM CST
In the first known report of its kind, a study published in the January 1st issue of the journal SLEEP finds that sleep disturbances are common among suicide attempters, and that nightmares are associated with suicidality.
The study, conducted by Nisse Sjöström, RN, and colleagues of Sahlgrenska University Hospital in Göteborg, Sweden, focused on 165 patients between the ages of 18-68, who were admitted to medical units or psychiatric wards at Sahlgrenska after a suicide attempt. It was discovered that 89 percent of subjects reported some kind of sleep disturbance. The most common complaint was difficulties initiating sleep (73 percent), followed by difficulties maintaining sleep (69 percent), nightmares (66 percent) and early morning awakening (58 percent). Nightmares were associated with a five-fold increase in risk for high suicidality. "Our finding of an association between nightmares and suicidality does not imply causality," said Sjöström. "However, our findings should inspire clinicians to include questions concerning sleep disturbance and especially nightmares in the clinical assessment of suicidal patients." Nightmares are disturbing, visual dream sequences that occur in your mind and wake you up from your sleep. Nightmares are very common and can begin at any age. Between 50-85 percent of adults report having a nightmare at least on occasion. They tend to become less frequent and intense as you age. Teen and adult women report nightmares more often than teen and adult men. Parents can also be disturbed of their sleep if their children have severe nightmares. Nightmare disorder develops when you have nightmares on a frequent basis. Nightmare disorder is not as common. About two to eight percent of people have a current problem with nightmares. The use of some medications may be a cause of nightmare disorder. You may be more likely to have nightmare disorder if a relative also has it. You should see a sleep specialist if your nightmares cause you great anxiety or often disrupt your sleep. A sleep specialist will help make an accurate diagnosis of your problem. He or she will also rule out possible underlying causes of the problem. While sleep specialists do not typically treat nightmares, most often they refer you to an experienced counselor or psychologist. |
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