Posts tagged psychology
Articles and news from the latest research reports.
Extended sleep reduces pain sensitivity
A new study suggests that extending nightly sleep in mildly sleepy, healthy adults increases daytime alertness and reduces pain sensitivity.
"Our results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures," said Timothy Roehrs, PhD, the study’s principal investigator and lead author. "We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine."
The study, appearing in the December issue of the journal SLEEP, involved 18 healthy, pain-free, sleepy volunteers. They were randomly assigned to four nights of either maintaining their habitual sleep time or extending their sleep time by spending 10 hours in bed per night. Objective daytime sleepiness was measured using the multiple sleep latency test (MSLT), and pain sensitivity was assessed using a radiant heat stimulus.
Results show that the extended sleep group slept 1.8 hours more per night than the habitual sleep group. This nightly increase in sleep time during the four experimental nights was correlated with increased daytime alertness, which was associated with less pain sensitivity.
In the extended sleep group, the length of time before participants removed their finger from a radiant heat source increased by 25 percent, reflecting a reduction in pain sensitivity. The authors report that the magnitude of this increase in finger withdrawal latency is greater than the effect found in a previous study of 60 mg of codeine.
According to the authors, this is the first study to show that extended sleep in mildly, chronically sleep deprived volunteers reduces their pain sensitivity. The results, combined with data from previous research, suggest that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.
Men and women explore the visual world differently
Everyone knows that men and women tend to hold different views on certain things. However, new research by scientists from the University of Bristol and published in PLoS ONE indicates that this may literally be the case.
Researchers examined where men and women looked while viewing still images from films and pieces of art. They found that while women made fewer eye movements than men, those they did make were longer and to more varied locations.These differences were largest when viewing images of people. With photos of heterosexual couples, both men and women preferred looking at the female figure rather than the male one. However, this preference was even stronger for women.
While men were only interested in the faces of the two figures, women’s eyes were also drawn to the rest of the bodies - in particular that of the female figure.
Felix Mercer Moss, PhD student in the Department of Computer Science who led the study, said: “The study represents the most compelling evidence yet that, despite occupying the same world, the viewpoints of men and women can, at times, be very different.
“Our findings have important implications for both past and future eye movement research together with future technological applications.”
Repeated Knocks to the Head Leads to Newly Recognized Brain Disease
Reports on the danger of head trauma in athletes and soldiers has pervaded the news in recent years. NFL and NHL player deaths have catapulted this problem into the limelight, with stories appearing in the New York Times, NPR, ESPN, 60 Minutes and even television entertainment shows. Media attention has raced far ahead of the science on this degenerative condition. But scientists are catching on. They have given this disease its own definition—chronic traumatic encephalopathy (CTE). Different from traumatic brain injury, Alzheimer’s, Parkinson’s, or ALS, they say CTE can strike adult and youths alike. Special coverage by Alzforum, the leading news source on Alzheimer’s and related diseases research, summarizes the status of research in this burgeoning field as researchers take steps to diagnose and treat CTE.
Autism severity may stem from fear
Most people know when to be afraid and when it’s ok to calm down.
But new research on autism shows that children with the diagnosis struggle to let go of old, outdated fears. Even more significantly, the Brigham Young University study found that this rigid fearfulness is linked to the severity of classic symptoms of autism, such as repeated movements and resistance to change.
For parents and others who work with children diagnosed with autism, the new research highlights the need to help children make emotional transitions – particularly when dealing with their fears.
“People with autism likely don’t experience or understand their world in the same way we do,” said Mikle South, a psychology professor at BYU and lead author of the study. “Since they can’t change the rules in their brain, and often don’t know what to expect from their environment, we need to help them plan ahead for what to expect.”
The complete study appears in the journal Autism Research.
Duetting musicians sync brainwaves even when playing different notes
According to a study published by a team of psychologists, musicians playing different parts of a duet aren’t just syncing time — they synchronise brainwaves.
Johanna Sänger of Berlin’s Max Planck Institute for Human Development gathered 32 guitarists and arranged them in pairs to play Sonata in G Major by Christian Gottlieb Scheidler. Each musician was hooked up to electrodes, so Sänger and her team could monitor their brain activity the 60 times they were asked to play the composition. An earlier study from the Institute had already demonstrated that guitarists playing the exact same tune begin to share brainwave patterns. However, in this study Sänger asked the musicians to play different parts from the same piece of music. As well as playing totally different notes, one was asked to take the lead and set the tempo for the other to follow. Her hypothesis was that, if the brainwave patterns again aligned, then it would demonstrate they have an inherently important role in musicians’ “interpersonally coordinated behaviour” — or, their ability to play well as a pair. All pairs did in fact present with synchronised brain oscillations.
"When people coordinate their own actions, small networks between brain regions are formed," said Sänger. "But we also observed similar network properties between the brains of the individual players, especially when mutual coordination is very important; for example at the joint onset of a piece of music."
The synchronisation is known as “phase locking”, and took place largely where the frontal and central electrodes were placed (the frontal lobe is responsible for retaining long term memory, aligning emotion memory with social norms and predicting an action’s consequences).
The results prove, says the paper, that synchronisation of brain patterns plays “a functional role in music performance”, but also “that brain mechanisms indexed by phase locking, phase coherence, and structural properties of within-brain and hyperbrain networks support interpersonal action coordination”.
Sänger also found that the “leader’s” brainwaves were stronger and began before the music did, demonstrating their “decision to begin playing at a certain moment in time” as represented by well-coordinated frontal lobe activity.
Where does it hurt? Pain map discovered in the human brain
Scientists have revealed the minutely detailed pain map of the hand that is contained within our brains, shedding light on how the brain makes us feel discomfort and potentially increasing our understanding of the processes involved in chronic pain.
The map, uncovered by scientists at UCL, is the first to reveal how finely-tuned the brain is to pain. Published in the Journal of Neuroscience, the study uses fMRI techniques in conjunction with laser stimuli to the fingers to plot the exact response to pain across areas of the brain.
“The results reveal that pain can be finely mapped in the brain,” said lead author Dr Flavia Mancini (UCL Institute of Cognitive Neuroscience). “While many studies have examined the brain response to pain before, our study is the first to map pain responses for the individual digits of the human hand.”
Using an fMRI brain imaging technique originally created to map the visual field, the researchers were able to distinguish the brain’s responses to painful laser heat stimuli on each finger in seven healthy participants, and to study their organisation in the brain.
This enabled the team to produce a fine-grained map showing how pain in the right hand results in certain parts of the brain being activated in the primary somatosensory cortex, an area in the left hemisphere of the brain which is involved in processing bodily information.
When comparing this pain map to ones generated by non-painful touch to the right hand, the researchers found that the two were very similar, with each map aligning with one another in each of the seven volunteers tested.
“The cells in the skin that respond to pain and the cells that respond to touch have very different structures and distributions, so we were surprised to find that the maps of pain and of touch were so similar in the brain,” said Dr Mancini. “The striking alignment of pain and touch maps suggests powerful interactions between the two systems.”
The pain maps could be used to provide markers for the location of pain in the human brain, enabling clinicians to see how patients’ brains reorganise following chronic pain.
“We know that the organisation of other sensory maps in the brain is altered in patients with chronic pain,” said Professor Patrick Haggard (UCL Institute of Cognitive Neuroscience). “Our method could next be used to track the reorganisation of brain maps that occurs in chronic pain, providing new insights into how the brain makes us feel pain. Therefore, measuring the map for pain itself is highly important.”
(Source: ucl.ac.uk)
Mediation Combined with Art Therapy Can Change Your Brain and Lower Anxiety
Cancer and stress go hand-in-hand, and high stress levels can lead to poorer health outcomes in cancer patients. The Jefferson-Myrna Brind Center of Integrative Medicine combined creative art therapy with a Mindfulness-based Stress Reduction (MBSR) program for women with breast cancer and showed changes in brain activity associated with lower stress and anxiety after the eight-week program. Their new study appears in the December issue of the journal Stress and Health.
Daniel Monti, MD, director of the Jefferson-Myrna Brind Center of Integrative Medicine and lead author on the study, and colleagues have previously published on the success of Mindfulness-based Art Therapy (MBAT) at helping cancer patients lower stress levels and improve quality of life.
“Our goal was to observe possible mechanisms for the observed psychosocial effects of MBAT by evaluating the cerebral blood flow (CBF) changes associated with an MBAT intervention in comparison with a control of equal time and attention,” says Monti. “This type of expressive art and meditation program has never before been studied for physiological impact and the correlation of that impact to improvements in stress and anxiety.”
The placebo effect goes beyond humans
Rats and humans have at least one thing in common: They both react the same way to a placebo, according to a new University of Florida study.
“That was the big finding — that the animals that expected pain relief actually got pain relief when you gave them an inert substance,” said co-author John Neubert, a pain specialist and an associate professor with the UF College of Dentistry department of orthodontics. “It helps validate our model that what we do in the rats, we believe, is a good representation of what’s being seen in humans.”
The investigation of placebo effects might lead to the identification of new therapeutic targets in the brain and of novel treatment strategies for a variety of health conditions.
A placebo response is a response seemingly to a treatment that has not actually been administered. For this study researchers looked at placebo responses in reference to pain and pain relief by evaluating how an animal responds when it “thinks” it’s getting a pain reliever.
UF researchers conditioned rats to expect morphine or salt water by giving injections of one or the other for two sessions. Then during the third session, researchers gave both groups the saline injection. About 30 to 40 percent of the group that had previously received morphine acted as if they had received morphine again and showed pain relief.
“What that means is we can then go ahead and do more mechanistic studies and do pharmacological studies targeting different receptors,” he said. “We could do different procedures and try to apply that knowledge into what we think is going on in humans.”
The two-year study published in the journal PAIN in October was the result of collaboration between Neubert and Niall Murphy, an addiction specialist and adjunct associate professor at the University of California Los Angeles. The two decided to look at placebo responses because that deals with pathways and mechanisms that relate to pain, reward and addiction.
According to psychological lore, when it comes to items of information the mind can cope with before confusion sets in, the “magic” number is seven. But a new analysis by a leading Australian psychiatrist challenges this long-held view, suggesting the number might actually be four.
In 1956, American psychologist George Miller published a paper in the influential journal Psychological Review arguing the mind could cope with a maximum of only seven chunks of information. The paper, “The Magical Number Seven, Plus or Minus Two. Some Limits on Our Capacity for Processing Information”, has since become one of the most highly cited psychology articles and has been judged by the Psychological Review as its most influential paper of all time.
But UNSW professor of psychiatry Gordon Parker says a re-analysis of the experiments used by Miller shows he missed the correct number by a wide mark. Writing in the journal Acta Psychiatrica Scandinavica, Scientia Professor Parker says a closer look at the evidence shows the human mind copes with a maximum of four ‘chunks’ of information, not seven.
“So to remember a seven numeral phone number, say 6458937, we need to break it into four chunks: 64. 58. 93. 7. Basically four is the limit to our perception.
“That’s a big difference for a paper that is one of the most highly referenced psychology articles ever – nearly a 100 percent discrepancy,” he suggests.
Professor Parker says the success of the original paper lies “more in its multilayered title and Miller’s evocative use of the word ‘magic’,” than in the science.
Professor Parker says 50 years after Miller there is still uncertainty about the nature of the brain’s storage capacity limits: “There may be no limit in storage capacity per se but only a limit to the duration in which items can remain active in short-term memory”. “Regardless, the consensus now is that humans can best store only four chunks in short-term memory tasks,” he says.