brain

Did she then accept as an article of belief the theory of astrological influences upon sublunary disasters?

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The benefits of mindfulness meditation, increasingly popular in recent years, are supposed to be many: reduced stress and risk for various diseases, improved well-being, a rewired brain. But the experimental bases to support these claims have been few. Supporters of the practice have relied on very small samples of unrepresentative subjects, like isolated Buddhist monks who spend hours meditating every day, or on studies that generally were not randomized and did not include placebo­control groups.

This month, however, a study published in Biological Psychiatry brings scientific thoroughness to mindfulness meditation and for the first time shows that, unlike a placebo, it can change the brains of ordinary people and potentially improve their health. […]

First they recruited 35 unemployed men and women who were seeking work and experiencing considerable stress. Blood was drawn and brain scans were given. Half the subjects were then taught formal mindfulness meditation at a residential retreat center; the rest completed a kind of sham mindfulness meditation that was focused on relaxation and distracting oneself from worries and stress. […]

At the end of three days, the participants all told the researchers that they felt refreshed and better able to withstand the stress of unemployment. Yet follow-up brain scans showed differences in only those who underwent mindfulness meditation. There was more activity, or communication, among the portions of their brains that process stress-related reactions and other areas related to focus and calm. Four months later, those who had practiced mindfulness showed much lower levels in their blood of a marker of unhealthy inflammation than the relaxation group, even though few were still meditating.

{ NY Times | Continue reading }

(The freckled face of Sweny, the druggist, appeals in the disc of the soapsun.)

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Marijuana is one of the most commonly used drugs in the United States, and use during adolescence — when the brain is still developing — has been proposed as a cause of poorer neurocognitive outcome. Nonetheless, research on this topic is scarce and often shows conflicting results, with some studies showing detrimental effects of marijuana use on cognitive functioning and others showing no significant long-term effects.

The purpose of the present study was to examine the associations of marijuana use with changes in intellectual performance in two longitudinal studies of adolescent twins (n = 789 and n = 2,277). We used a quasiexperimental approach to adjust for participants’ family background characteristics and genetic propensities, helping us to assess the causal nature of any potential associations. Standardized measures of intelligence were administered at ages 9–12 y, before marijuana involvement, and again at ages 17–20 y. Marijuana use was self-reported at the time of each cognitive assessment as well as during the intervening period.

Marijuana users had lower test scores relative to nonusers and showed a significant decline in crystallized intelligence between preadolescence and late adolescence. However, there was no evidence of a dose–response relationship between frequency of use and intelligence quotient (IQ) change. Furthermore, marijuana-using twins failed to show significantly greater IQ decline relative to their abstinent siblings.

Evidence from these two samples suggests that observed declines in measured IQ may not be a direct result of marijuana exposure but rather attributable to familial factors that underlie both marijuana initiation and low intellectual attainment.

{ Proceedings of the National Academy of Sciences }

photo { Julia Margaret Cameron, Paul and Virginia, 1864 }

‘The flame is not so bright to itself as to those on whom it shines: so too the wise man.’ —Nietzsche

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Starting at age 55, our hippocampus, a brain region critical to memory, shrinks 1 to 2 percent every year, to say nothing of the fact that one in nine people age 65 and older has Alzheimer’s disease. The number afflicted is expected to grow rapidly as the baby boom generation ages. Given these grim statistics, it’s no wonder that Americans are a captive market for anything, from supposed smart drugs and supplements to brain training, that promises to boost normal mental functioning or to stem its all-too-common decline. […]

A few years back, a joint study by BBC and Cambridge University neuroscientists put brain training to the test. Their question was this: Do brain gymnastics actually make you smarter, or do they just make you better at doing a specific task? […] All subjects took a benchmark cognitive test, a kind of modified I.Q. test, at the beginning and at the end of the study. Although improvements were observed in every cognitive task that was practiced, there was no evidence that brain training made people smarter.

There was, however a glimmer of hope for subjects age 60 and above. Unlike the younger participants, older subjects showed a significant improvement in verbal reasoning, one of the components of the benchmark test, after just six weeks of brain training, so the older subjects continued in a follow-up study for a full 12 months.

Results of this follow-up study, soon to be published in a peer-reviewed journal, generally show that continued brain training helps older subjects maintain the improvement in verbal reasoning seen in the earlier study. This is good news because it suggests that brain exercise might delay some of the effects of aging on the brain.

{ NY Times | Continue reading }

‘If youth were not ignorant and timid, civilization would be impossible.’ –Balzac

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In a stunning discovery that overturns decades of textbook teaching, researchers at the University of Virginia School of Medicine have determined that the brain is directly connected to the immune system by vessels previously thought not to exist. That such vessels could have escaped detection when the lymphatic system has been so thoroughly mapped throughout the body is surprising on its own, but the true significance of the discovery lies in the effects it could have on the study and treatment of neurological diseases ranging from autism to Alzheimer’s disease to multiple sclerosis.

{ EurekAlert | Continue reading }

unrelated { The benefits of a herpes infection }

“La vieillesse est un naufrage.” –Chateaubriand

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Ageing causes changes to the brain size, vasculature, and cognition. The brain shrinks with increasing age and there are changes at all levels from molecules to morphology. Incidence of stroke, white matter lesions, and dementia also rise with age, as does level of memory impairment and there are changes in levels of neurotransmitters and hormones. Protective factors that reduce cardiovascular risk, namely regular exercise, a healthy diet, and low to moderate alcohol intake, seem to aid the ageing brain as does increased cognitive effort in the form of education or occupational attainment. A healthy life both physically and mentally may be the best defence against the changes of an ageing brain. Additional measures to prevent cardiovascular disease may also be important. […]

It has been widely found that the volume of the brain and/or its weight declines with age at a rate of around 5% per decade after age 40 with the actual rate of decline possibly increasing with age particularly over age 70. […]

The most widely seen cognitive change associated with ageing is that of memory. Memory function can be broadly divided into four sections, episodic memory, semantic memory, procedural memory, and working memory.18 The first two of these are most important with regard to ageing. Episodic memory is defined as “a form of memory in which information is stored with ‘mental tags’, about where, when and how the information was picked up”. An example of an episodic memory would be a memory of your first day at school, the important meeting you attended last week, or the lesson where you learnt that Paris is the capital of France. Episodic memory performance is thought to decline from middle age onwards. This is particularly true for recall in normal ageing and less so for recognition. It is also a characteristic of the memory loss seen in Alzheimer’s disease (AD). […]

Semantic memory is defined as “memory for meanings”, for example, knowing that Paris is the capital of France, that 10 millimetres make up a centimetre, or that Mozart composed the Magic Flute. Semantic memory increases gradually from middle age to the young elderly but then declines in the very elderly.

{ Postgraduate Medical Journal | Continue reading | Thanks Tim}

‘The bassoon or the piccolo, grumbling its discontent or shrilling its longing, personify the empty stomach for me.’ –Gioachino Rossini

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Scientists are increasingly convinced that the vast assemblage of microfauna in our intestines may have a major impact on our state of mind. The gut-brain axis seems to be bidirectional—the brain acts on gastrointestinal and immune functions that help to shape the gut’s microbial makeup, and gut microbes make neuroactive compounds, including neurotransmitters and metabolites that also act on the brain. […]

Microbes may have their own evolutionary reasons for communicating with the brain. They need us to be social, says John Cryan, a neuroscientist at University College Cork in Ireland, so that they can spread through the human population. Cryan’s research shows that when bred in sterile conditions, germ-free mice lacking in intestinal microbes also lack an ability to recognize other mice with whom they interact. In other studies, disruptions of the microbiome induced mice behavior that mimics human anxiety, depression and even autism. In some cases, scientists restored more normal behavior by treating their test subjects with certain strains of benign bacteria. Nearly all the data so far are limited to mice, but Cryan believes the findings provide fertile ground for developing analogous compounds, which he calls psychobiotics, for humans. “That dietary treatments could be used as either adjunct or sole therapy for mood disorders is not beyond the realm of possibility,” he says.

{ Scientific American | Continue reading }

related { Is Neuroscience Based On Biology? }

’just figured out katy perry is walmart’ —@CHERiCHERi69

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Individuals who report experiencing communication with deceased persons are traditionally called mediums. During a typical mediumship reading, a medium conveys messages from deceased persons to the living (i.e., sitters). There are two types of mediumship: mental and physical. In mental mediumship, communication with deceased persons is experienced “through interior vision or hearing, or through the spirits taking over and controlling their bodies or parts thereof, especially … the parts required for speech and writing.” During physical mediumship, the experienced communication “proceeds through paranormal physical events in the medium’s vicinity,” which have included reports of independent voices, rapping sounds on walls or tables, and movement of objects. […]

Recent research has also confirmed previous findings that mediumship is not associated with conventional dissociative experiences, pathology, dysfunction, psychosis, or over-active imaginations. Indeed, a large percentage of mediums have been found to be high functioning, socially accepted individuals within their communities. […]

Psychometric and brain electrophysiology data were collected from six individuals who had previously reported accurate information about deceased individuals under double-blind conditions. Each experimental participant performed two tasks with eyes closed.

In the first task, the participant was given only the first name of a deceased person and asked 25 questions. After each question, the participant was asked to silently perceive information relevant to the question for 20 s and then respond verbally. Responses were transcribed and then scored for accuracy by individuals who knew the deceased persons. Of the four mediums whose accuracy could be evaluated, three scored significantly above chance (p < 0.03). The correlation between accuracy and brain activity during the 20 s of silent mediumship communication was significant in frontal theta for one participant (p < 0.01).

In the second task, participants were asked to experience four mental states for 1 min each: (1) thinking about a known living person, (2) listening to a biography, (3) thinking about an imaginary person, and (4) interacting mentally with a known deceased person. Each mental state was repeated three times. Statistically significant differences at p < 0.01 after correction for multiple comparisons in electrocortical activity among the four conditions were obtained in all six participants, primarily in the gamma band (which might be due to muscular activity). These differences suggest that the impression of communicating with the deceased may be a distinct mental state distinct from ordinary thinking or imagination.

{ Frontiers in Psychology | PDF }

‘There are ideal series of events which run parallel with the real ones. They rarely coincide.’ –Novalis

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A car accident, the loss of a loved one and financial trouble are just a few of the myriad stressors we may encounter in our lifetimes. Some of us take it in stride, while others go on to develop anxiety or depression. How well will we deal with the inevitable lows of life?

A clue to this answer, according to a new Duke University study, is found in an almond-shaped structure deep within our brains: the amygdala. By measuring activity of this area, which is crucial for detecting and responding to danger, researchers say they can tell who will become depressed or anxious in response to stressful life events, as far as four years down the road.

{ EurekAlert | Continue reading }

‘What does a woman want?’ –Freud

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[T]he patient was a woman who, although she was being examined in my office at New York Hospital, claimed we were in her home in Freeport, Maine. The standard interpretation of this syndrome is that she made a duplicate copy of a place (or person) and insisted that there are two. […]

This woman was intelligent; before the interview she was biding her time reading the New York Times. I started with the ‘So, where are you?’ question. ‘I am in Freeport, Maine. I know you don’t believe it. Dr Posner told me this morning when he came to see me that I was in Memorial Sloan-Kettering Hospital. […] Well, that is fine, but I know I am in my house on Main Street in Freeport, Maine!’ I asked, ‘Well, if you are in Freeport and in your house, how come there are elevators outside the door here?’

The grand lady peered at me and calmly responded, ‘Doctor, do you know how much it cost me to have those put in?’ […]

Because of her lesion the part of the brain that represents locality is overactive and sending out an erroneous message about her location. The interpreter is only as good as the information it receives, and in this instance it is getting a wacky piece of information.

{ NeuroDojo | Continue reading }

‘Jean-Michel came over to the office to paint but he fell asleep on the floor… I woke him up and he did two masterpieces.’ —Warhol

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University of Washington researchers have successfully replicated a direct brain-to-brain connection between pairs of people. […] Researchers were able to transmit the signals from one person’s brain over the Internet and use these signals to control the hand motions of another person within a split second of sending that signal.

{ University of Washington | Continue reading }

When I to sulphurous and tormenting flames must render up myself

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Have you ever felt lost and alone? If so, this experience probably involved your hippocampus, a seahorse-shaped structure in the middle of the brain. About 40 years ago, scientists with electrodes discovered that some neurons in the hippocampus fire each time an animal passes through a particular location in its environment. These neurons, called place cells, are thought to function as a cognitive map that enables navigation and spatial memory.

Place cells are typically studied by recording from the hippocampus of a rodent navigating through a laboratory maze. But in the real world, rats can cover a lot of ground. For example, many rats leave their filthy sewer bunkers every night to enter the cozy bedrooms of innocent sleeping children.

In a recent paper, esteemed neuroscientist Dr. Dylan Rich and colleagues investigated how place cells encode very large spaces. Specifically, they asked: how are new place cells recruited to the network as a rat explores a truly giant maze?

{ Sick papes | Continue reading }

You’re waiting for a train. A train that’ll take you far away. You know where you hope this train will take you. But you can’t know for sure. Yet it doesn’t matter. Now, tell me why?

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A woman has reached the age of 24 without anyone realising she was missing a large part of her brain. […] The discovery was made when the woman was admitted to the Chinese PLA General Hospital of Jinan Military Area Command in Shandong Province complaining of dizziness and nausea. She told doctors she’d had problems walking steadily for most of her life, and her mother reported that she hadn’t walked until she was 7 and that her speech only became intelligible at the age of 6.

Doctors did a CAT scan and immediately identified the source of the problem – her entire cerebellum was missing. The space where it should be was empty of tissue. Instead it was filled with cerebrospinal fluid, which cushions the brain and provides defence against disease.

The cerebellum – sometimes known as the “little brain” – is located underneath the two hemispheres. It looks different from the rest of the brain because it consists of much smaller and more compact folds of tissue. It represents about 10 per cent of the brain’s total volume but contains 50 per cent of its neurons. […]

The cerebellum’s main job is to control voluntary movements and balance, and it is also thought to be involved in our ability to learn specific motor actions and speak.

{ NewScientist | Continue reading }