29 November 2011
As we get older, our cognitive abilities change, improving when we're younger and declining as we age. Scientists posit a hierarchical structure within which these abilities are organized. There's the "lowest" level -- measured by specific tests, such as story memory or word memory; the second level, which groups various skills involved in a category of cognitive ability, such as memory, perceptual speed, or reasoning; and finally, the "general," or G, factor, a sort of statistical aggregate of all the thinking abilities.
What happens to this structure as we age? That was the question Timothy A. Salthouse, Brown-Forman professor of psychology at the University of Virginia, investigated in a new study appearing in an upcoming issue of Psychological Science, a journal published by the Association for Psychological Science. His findings advance psychologists' understanding of the complexities of the aging brain.
"There are three hypotheses about how this works," says Salthouse. "One is that abilities become more strongly integrated with one another as we age." That theory suggests the general factor influences cognitive aging the most. The second -- based on the idea that connectivity among different brain regions lessens with age -- "is almost the opposite: that the changes in cognitive abilities become more rather than less independent with age." The third was Salthouse's hypothesis: The structure remains constant throughout the aging process.
Using a sample of 1,490 healthy adults ages 18 to 89, Salthouse performed analyses of the scores on 16 tests of five cognitive abilities -- vocabulary, reasoning, spatial relations, memory, and perceptual speed. The primary analyses were on the changes in the test scores across an interval of about two and a half years.
The findings confirmed Salthouse's hunch: "The effects of aging on memory, on reasoning, on spatial relations, and so on are not necessarily constant. But the structure within which these changes are occurring does not seem to change as a function of age." In normal, healthy people, "the direction and magnitude of change may be different" when we're 18 or 88, he says. "But it appears that the qualitative nature of cognitive change remains the same throughout adulthood."
The study could inform other research investigating "what allows some people to age more gracefully than others," says Salthouse. That is, do people who stay mentally sharper maintain their ability structures better than those who become more forgetful or less agile at reasoning? And in the future, applying what we know about the structures of change could enhance "interventions that we think will improve cognitive functioning" at any age or stage of life.
24 November 2011
UC Berkeley researchers have found that stress chemicals shut down and the brain processes emotional experiences during the REM dream phase of sleep
They say time heals all wounds, and new research from the University of California, Berkeley, indicates that time spent in dream sleep can help.
UC Berkeley researchers have found that during the dream phase of sleep, also known as REM sleep, our stress chemistry shuts down and the brain processes emotional experiences and takes the painful edge off difficult memories.
The findings offer a compelling explanation for why people with post-traumatic stress disorder (PTSD), such as war veterans, have a hard time recovering from painful experiences and suffer reoccurring nightmares.They also offer clues into why we dream.
"The dream stage of sleep, based on its unique neurochemical composition, provides us with a form of overnight therapy, a soothing balm that removes the sharp edges from the prior day's emotional experiences," said Matthew Walker, associate professor of psychology and neuroscience at UC Berkeley and senior author of the study to be published this Wednesday, Nov. 23, in the journal Current Biology.
For people with PTSD, Walker said, this overnight therapy may not be working effectively, so when a "flashback is triggered by, say, a car backfiring, they relive the whole visceral experience once again because the emotion has not been properly stripped away from the memory during sleep."
The results offer some of the first insights into the emotional function of Rapid Eye Movement (REM) sleep, which typically takes up 20 percent of a healthy human's sleeping hours. Previous brain studies indicate that sleep patterns are disrupted in people with mood disorders such as PTSD and depression.
While humans spend one-third of their lives sleeping, there is no scientific consensus on the function of sleep. However, Walker and his research team have unlocked many of these mysteries linking sleep to learning, memory and mood regulation. The latest study shows the importance of the REM dream state.
"During REM sleep, memories are being reactivated, put in perspective and connected and integrated, but in a state where stress neurochemicals are beneficially suppressed," said Els van der Helm, a doctoral student in psychology at UC Berkeley and lead author of the study.
Thirty–five healthy young adults participated in the study. They were divided into two groups, each of whose members viewed 150 emotional images, twice and 12 hours apart, while an MRI scanner measured their brain activity.
Half of the participants viewed the images in the morning and again in the evening, staying awake between the two viewings. The remaining half viewed the images in the evening and again the next morning after a full night of sleep.
Those who slept in between image viewings reported a significant decrease in their emotional reaction to the images. In addition, MRI scans showed a dramatic reduction in reactivity in the amygdala, a part of the brain that processes emotions, allowing the brain's "rational" prefrontal cortex to regain control of the participants' emotional reactions.
In addition, the researchers recorded the electrical brain activity of the participants while they slept, using electroencephalograms. They found that during REM dream sleep, certain electrical activity patterns decreased, showing that reduced levels of stress neurochemicals in the brain soothed emotional reactions to the previous day's experiences.
"We know that during REM sleep there is a sharp decrease in levels of norepinephrine, a brain chemical associated with stress," Walker said. "By reprocessing previous emotional experiences in this neuro-chemically safe environment of low norepinephrine during REM sleep, we wake up the next day, and those experiences have been softened in their emotional strength. We feel better about them, we feel we can cope."
Walker said he was tipped off to the possible beneficial effects of REM sleep on PTSD patients when a physician at a U.S. Department of Veterans Affairs hospital in the Seattle area told him of a blood pressure drug that was inadvertently preventing reoccurring nightmares in PTSD patients.
It turns out that the generic blood pressure drug had a side effect of suppressing norepinephrine in the brain, thereby creating a more stress-free brain during REM, reducing nightmares and promoting a better quality of sleep. This suggested a link between PTSD and REM sleep, Walker said.
"This study can help explain the mysteries of why these medications help some PTSD patients and their symptoms as well as their sleep," Walker said. "It may also unlock new treatment avenues regarding sleep and mental illness."
Other co-authors of the study are UC Berkeley sleep researchers Justin Yao, Shubir Dutt, Vikram Rao and Jared Saletin.
Posted by Harvinder Saraswat at 11:51:00 am
14 November 2011
Online psychology clinics could help people cope with a variety of anxiety disorders, Australian experience reveals.
The Anxiety Online clinic of the Swinburne University of Technology has been lauded by the Journal of Medical Internet Research. The eTherapy programs of the clinic are tailored to treat generalised anxiety, panic, obsessive-compulsive, post-traumatic stress and social anxiety disorders.
More than 220 people with an least one mild anxiety symptom – who completed one of the five fully-automated programs over 12 weeks – showed significant improvements on 21 of 25 measures, Swinburne researchers have reported.
Each program consists of 12 modules using text-based and multimedia materials such as audio, video and animated graphics and online activities.
Swinburne National eTherapy Centre Director Associate Professor Britt Klein said that although the findings need to be replicated, the preliminary results were very pleasing.
“Essentially we have found that consumers who completed one of our self-help treatment programs reported significantly lower clinical disorder severity ratings at the three month assessment. They also became more confident in managing their own mental health care.
“Furthermore, we found significant reductions in the types of mental health symptoms and psychological distress, as well as an increase in quality of life scores for most of our five eTherapy programs,’’ she said.
In any given year, about 20 per cent of the Australian population has a diagnosable mental health condition. But ABS research has shown that only about a third of these people access the mental health services they need.
“The advent of open-access e-mental health services will undoubtedly be one very important means of providing Australians with greater choice and timely access to mental health assistance,” Associate Professor Klein said.
Deputy CEO of beyondblue, Dr Nicole Highet, said online eTherapy may be an effective alternative for people with depression and anxiety who can’t or won’t access help from mental health professionals.
“We know that more than half of all Australians with depression and anxiety don’t get the help they need for a range of reasons. There may be a lack of services in their area, they may not be able to afford the consultation fees or perhaps they’re too embarrassed or ashamed to ask for help," Dr Highet said.
Over 7000 people have completed e-PASS, an online psychological and assessment referral system, through Anxiety Online. When compared to the labour costs involved in traditional face-to-face services, this has resulted in a potential crude cost saving of AUD$6.7 million in the first 18 months of the online clinic’s operation.
Anxiety Online will soon become Mental Health Online as new eTherapy treatment programs for depression, bulimia, insomnia, problem gambling, drugs and alcohol and hoarding are offered.
From mid 2012 Mental Health Online consumers who opt for therapist assistance will be able to choose from email, instant messaging, audio or video-chat, as well as communicating and interacting within 3D virtual reality environments and collaborative working spaces.
Anxiety Online is funded by the Australian Government Department of Health and Ageing, and in future will be accessible via the emerging National e-Mental Health Portal.
4 November 2011
November 3, 2011 — A new study provides more evidence that people with schizophrenia have a diminished sense of mind–body connection, or "body ownership," and hints that yoga and other types of movement therapy that get patients to focus on their own body may be helpful.
Katharine N. Thakkar, PhD, from the Department of Psychology, Vanderbilt University in Nashville, Tennessee, and colleagues measured the strength of body ownership of 24 schizophrenia outpatients and 21 healthy control patients by testing their susceptibility to the rubber hand illusion (RHI).
First described in 1998, this tactile illusion is induced by simultaneously stroking a visible rubber hand and the participant's own hidden hand.
"Watching a rubber hand being stroked while one's own unseen hand is stroked simultaneously often leads to a sense of ownership over the rubber hand and a shift in perceived position of the real hand toward the rubber hand," the investigators explain in their paper. "The RHI is reduced or absent when tactile stimulation of the real and rubber hands is asynchronous or when the rubber hand is spatially incongruent with the real hand," they write.
The study was published online October 31 in PLoS One.
Weakened Sense of Self
The investigators found that patients with schizophrenia were more susceptible to the RHI than healthy control patients.
"After a while, patients with schizophrenia begin to 'feel' the rubber hand and disown their own hand," author Sohee Park, PhD, also from the Department of Psychology at Vanderbilt, explained in a statement. "They also experience their real hand as closer to the rubber hand.
Dr. Sohee Park
"Healthy people get this illusion too, but weakly. Some don't get it at all," Dr. Park said, suggesting that people with schizophrenia have a more flexible body representation and weakened sense of self.
"What's so interesting about Professor Park's study is that they have found that the sense of bodily ownership does not diminish among patients with schizophrenia, but it can be extended to other objects more easily," David M. Gray, PhD, Mellon assistant professor of philosophy at Vanderbilt, who was not involved in the study, told Medscape Medical News.
Dr. Park noted that there is significant individual variation in how people experience RHI that is related to a personality trait called schizotypy, "which is associated with psychosis-proneness."
Before the RHI, Dr. Park's team had participants complete a questionnaire to rate their degree of schizotypy, which is the extent to which they experience perceptual effects related to the illusion. The researchers found that participants who rated higher on the scale were more susceptible to the RHI.
The researchers also observed in both study groups that the skin temperature of the hidden hand drops by a few tenths of a degree during the RHI, although they are not sure why. "It's almost as if the hand is disowned and rejected, no longer part of the self," Dr. Park said.
Rubber hand illusion
The researchers also report that 1 patient with schizophrenia experienced a full out-of-body experience (OBE) during the RHI. The participant reported that he was floating above his own body for about 15 minutes. This patient had another OBE when invited back for a second RHI session. These occurrences suggest a link between "body disownership and psychotic experiences," the researchers write.
The OBE in this 1 patient that is "readily replicable" using the RHI "illustrates this temporary loss of body ownership in a spectacular way," Dr. Park told Medscape Medical News. She emphasized, however, that "most people in the general population who experience OBEs, especially before falling asleep, are perfectly healthy, and certainly not psychotic. This one case study by itself does not prove anything."
The researchers note that OBEs and body ownership are associated with the brain's temporoparietal junction, suggesting that disorders in this part of the brain may also contribute to schizophrenia symptoms.
The investigators note that yoga or other forms of physical activity that focus on the body might be helpful in patients with schizophrenia. They point to 2 recent studies in which yoga was shown to be effective in attenuating symptoms and increasing social functioning in schizophrenia, "exceeding the beneficial effects of aerobic exercise."
"If there are disturbances of body sense, it might be possible to anchor ourselves better by gaining more intimate and fine control over our body parts by practicing focused exercises," Dr. Park told Medscape Medical News.
"Obviously a careful, clinical trial is needed to evaluate the usefulness of these programs, but physical exercise is good for everybody, so I don't see any downside to this at all," she said.
"In addition to yoga, I think the Alexander technique, which is used by a lot of people with back problems or other injuries, could be interesting to explore because you really get to know your body and the space it occupies," Dr. Park said.
The study was supported in part by the National Institutes of Mental Health, National Alliance for Research on Schizophrenia and Depression, National Institute of Child Health and Human Development, and Gertrude Conaway Vanderbilt Endowed Chair. The authors and Dr. Gray have disclosed no relevant financial relationships.
Posted by Harvinder Saraswat at 3:55:00 pm
1 November 2011
In times of stress, we're often encouraged to pause for a moment and simply be in the 'now.' This kind of mindfulness, an essential part of Buddhist and Indian Yoga traditions, has entered the mainstream as people try to find ways to combat stress and improve their quality of life. And research suggests that mindfulness meditation can have benefits for health and performance, including improved immune function, reduced blood pressure, and enhanced cognitive function.
But how is it that a single practice can have such wide-ranging effects on well-being? A new article published in the latest issue of Perspectives on Psychological Science, a journal of the Association for Psychological Science, draws on the existing scientific literature to build a framework that can explain these positive effects.
The goal of this work, according to author Britta Hölzel, of Justus Liebig University and Harvard Medical School, is to "unveil the conceptual and mechanistic complexity of mindfulness, providing the 'big picture' by arranging many findings like the pieces of a mosaic." By using a framework approach to understand the mechanisms of mindfulness, Hölzel and her co-authors point out that what we think of as mindfulness is not actually a single skill. Rather, it is a multi-faceted mental practice that encompasses several mechanisms.
The authors specifically identify four key components of mindfulness that may account for its effects: attention regulation, body awareness, emotion regulation, and sense of self. Together, these components help us attend to and deal with the mental and physiological effects of stress in ways that are non-judgmental.
Although these components are theoretically distinct, they are closely intertwined. Improvement in attention regulation, for example, may directly facilitate our awareness of our physiological state. Body awareness, in turn, helps us to recognize the emotions we are experiencing. Understanding the relationships between these components, and the brain mechanisms that underlie them, will allow clinicians to better tailor mindfulness interventions for their patients, says Hölzel.
On the most fundamental level, this framework underscores the point that mindfulness is not a vague cure-all. Effective mindfulness meditation requires training and practice and it has distinct measurable effects on our subjective experiences, our behavior, and our brain function. The authors hope that further research on this topic will "enable a much broader spectrum of individuals to utilize mindfulness meditation as a versatile tool to facilitate change – both in psychotherapy and in everyday life."
For more information about this study, please contact: Britta K. Hölzel at firstname.lastname@example.org.
Perspectives on Psychological Science is ranked among the top 10 general psychology journals for impact by the Institute for Scientific Information. It publishes an eclectic mix of thought-provoking articles on the latest important advances in psychology. For a copy of the article "How Does Mindfulness Meditation Work? Proposing Mechanisms of Action From a Conceptual and Neural Perspective" and access to other Perspectives on Psychological Science research findings, please contact Divya Menon at 202-293-9300 or email@example.com.