Posts tagged psychology
Articles and news from the latest research reports.
People who take cocaine over many years without becoming addicted have a brain structure which is significantly different from those individuals who developed cocaine-dependence, researchers have discovered. New research from the University of Cambridge has found that recreational drug users who have not developed a dependence have an abnormally large frontal lobe, the section of the brain implicated in self-control. Their research was published in the journal Biological Psychiatry.
For the study, led by Dr Karen Ersche, individuals who use cocaine on a regular basis underwent a brain scan and completed a series of personality tests. The majority of the cocaine users were addicted to the drug but some were not (despite having used it for several years).
The scientists discovered that a region in the frontal lobes of the brain, known to be critically implicated in decision-making and self-control, was abnormally bigger in the recreational cocaine users. The Cambridge researchers suggest that this abnormal increase in grey matter volume, which they believe predates drug use, might reflect resilience to the effects of cocaine, and even possibly helps these recreational cocaine users to exert self-control and to make advantageous decisions which minimize the risk of them becoming addicted.
They found that this same region in the frontal lobes of the brain was significantly reduced in size in people with cocaine dependence, confirming earlier research that had found similar results. They believe that at least some of these changes are the result of drug use, which causes drug users to lose grey matter.
They also found that people who use illicit drugs like cocaine exhibit high levels of sensation-seeking personality traits, but only those developing dependence show personality traits of impulsivity and compulsivity.
Dr Ersche, of the Behavioural and Clinical Neuroscience Institute (BCNI) at the University of Cambridge, said: “These findings are important because they show that the use of cocaine does not inevitably lead to addiction in people with good self-control and no familial risk.
“Our findings indicate that preventative strategies might be more effective if they were tailored more closely to those individuals at risk according to their personality profile and brain structure.”
The researchers will next explore the basis of the recreational users’ apparent resilience to drug dependence. Dr Ersche added: “Their high level of education, less troubled family background or the beginning of drug-taking only after puberty may all play a role.”
Scanning the Brain: Scientists Examine the Impact of fMRI Over the Past 20 Years
Understanding the human brain is one of the greatest scientific quests of all time, but the available methods have been very limited until recently. The development of functional magnetic resonance imaging (fMRI) — a tool used to gauge real-time brain activity by measuring changes in blood flow — opened up an exciting new landscape for exploration.
Now, twenty years after the first fMRI study was published, a group of distinguished psychological scientists reflect on the contributions fMRI has made to our understanding of human thought. Their reflections are published as part of a special section of the January 2013 issue of Perspectives on Psychological Science, a journal of the Association for Psychological Science.
In the last two decades, many researchers have used fMRI to try to answer various questions about the brain and mind. But some are not convinced of its usefulness.
“Despite the many new methods and results derived from fMRI research, some have argued that fMRI has done very little to advance knowledge about cognition and, in particular, has done little to advance theories about cognitive processes,” write Mara Mather, Nancy Kanwisher, and John Cacioppo, editors of the special section.
The aim of the special section is to tackle the question of how fMRI results have (or have not) changed the way we think about human psychology and the brain, resulting in a collection of 12 provocative articles.
Some of the authors argue that fMRI has fundamentally changed that way that researchers think about the aging mind. According to researchers Tor Wager and Lauren Atlas, fMRI may also provide a more direct way of measuring pain.
Others discuss the contributions fMRI has made to the longstanding debate about whether cognitive operations are modular or distributed across domains. And some emphasize the reciprocal relationship between fMRI and cognitive theories, highlighting how each informs the others.
As appealing as fMRI images might be, researchers Martha Farah and Cayce Hook find little support for the claim that fMRI data has a “seductive allure” that makes it more persuasive than other types of data.
In their concluding commentary, Mather, Cacioppo, and Kanwisher argue that fMRI does provide unique insights to our understanding of cognition. But, as powerful as it is, the researchers acknowledge that there are some questions fMRI will never answer.
“The best approach to answering questions about cognition,” say Mather, Cacioppo, and Kanwisher, “is a synergistic combination of behavioral and neuroimaging methods, richly complemented by the wide array of other methods in cognitive neuroscience.”
(Image courtesy of Glasgow University)
The Connection Between Memory and Sleep
Researchers found information can be better retained with reinforcing stimuli delivered during sleep
When you’re studying for an exam, is there something you can do while you sleep to retain the information better?
"The question is, ‘What determines which information is going to be kept and which information is lost?’" says neuroscientist Ken Paller.
With support from the National Science Foundation (NSF), Paller and his team at Northwestern University are studying the connection between memory and sleep, and the possibilities of boosting memory storage while you snooze.
"We think many stages of sleep are important for memory. However, a lot of the evidence has shown that slow-wave sleep is particularly important for some types of memory," explains Paller.
Slow-wave sleep is often referred to as “deep sleep,” and consists of stages 3 and 4 of non-rapid-eye-movement sleep.
Paller’s lab group members demonstrated for Science Nation two of the tests they run on study participants. In the first experiment, the subjects learned two pieces of music in a format similar to the game Guitar Hero. During a short nap following learning, just one of the learned tunes was played softly several times, to selectively reinforce the memory for playing that tune without any reinforcement but not for the other tune. Paller wanted to know whether the test subjects could more accurately produce the tune played during sleep.
In the second exercise, the subjects were asked to memorize the location of 50 objects on a computer screen. The presentation of each object was coupled with a unique sound. During the post-learning nap, memory for the location of 25 objects was reinforced by the play-back of only 25 of the sounds. In this case, Paller wanted to know whether the subjects could remember object locations better if the associated sounds were played during sleep.
Researchers recorded electrical activity generated in the brain using EEG electrodes attached to the scalp. They thus determined whether the subjects entered “deep sleep,” and only those who did participated in the reinforcement experiments. In both experiments, participants did a better job remembering what was reinforced while they slept, compared to what was not reinforced.
"We think that memory processing happens during sleep every night," says Paller. "We’re at the beginning of finding out what types of memory can be reinforced, how large reinforcement effects can be, and what sorts of stimuli can be used to reactivate memories so that they can be better consolidated."
Paller’s goal is to better understand the fundamental brain mechanisms responsible for memory. And that, in turn, may help people with memory problems, including those who find themselves more forgetful as they age.
"We experience progressively less slow-wave sleep as we age. Of course, many brain mechanisms come into play to allow us to remember, including some processing that transpires during sleep. So, there’s a lot to figure out about how memory works, but I think it’s fair to say that the person you are when you’re awake is partly a function of what your brain does when you’re asleep," explains Paller. He says these reactivation techniques could turn out to be valuable for enhancing what people have learned.
"What is beautiful about this set of experiments is that Dr. Paller identified ‘deep sleep’ as a critical time window during which memory for specific experiences can be selectively enhanced by the method of reactivation without conscious effort," says Akaysha Tang, director of the cognitive neuroscience program in the NSF Directorate for Social, Behavioral and Economic Sciences.
"Normally, conscious rehearsal of memorized material is needed if one wants to remember something better or retain it for longer, and one has to find time to review or rehearse," continues Tang. "Dr. Paller and the members of his lab group showed that such selective enhancement could be achieved without conscious effort and without demanding more of one’s waking hours. So, instead of pulling that all-nighter to memorize the material, in the future, it may be possible to consolidate the memory by sleeping with a scientifically programmed lullaby!"
(Source: nsf.gov)
What is déjà vu and why does it happen?
Have you ever experienced a sudden feeling of familiarity while in a completely new place? Or the feeling you’ve had the exact same conversation with someone before?
This feeling of familiarity is, of course, known as déjà vu (a French term meaning “already seen”) and it’s reported to occur on an occasional basis in 60-80% of people. It’s an experience that’s almost always fleeting and it occurs at random.
So what is responsible for these feelings of familiarity?
Despite coverage in popular culture, experiences of déjà vu are poorly understood in scientific terms. Déjà vu occurs briefly, without warning and has no physical manifestations other than the announcement: “I just had déjà vu!”
Many researchers propose that the phenomenon is a memory-based experience and assume the memory centres of the brain are responsible for it.
Shakespeare and Wordsworth boost the brain, new research reveals
Scientists, psychologists and English academics at Liverpool University have found that reading the works of the Bard and other classical writers has a beneficial effect on the mind, catches the reader’s attention and triggers moments of self-reflection.
Using scanners, they monitored the brain activity of volunteers as they read works by William Shakespeare, William Wordsworth, T.S Eliot and others.
They then “translated” the texts into more “straightforward”, modern language and again monitored the readers’ brains as they read the words.
Scans showed that the more “challenging” prose and poetry set off far more electrical activity in the brain than the more pedestrian versions.
Scientists were able to study the brain activity as it responded to each word and record how it “lit up” as the readers encountered unusual words, surprising phrases or difficult sentence structure.
This “lighting up” of the mind lasts longer than the initial electrical spark, shifting the brain to a higher gear, encouraging further reading.
The research also found that reading poetry, in particular, increases activity in the right hemisphere of the brain, an area concerned with “autobiographical memory”, helping the reader to reflect on and reappraise their own experiences in light of what they have read. The academics said this meant the classics were more useful than self-help books.
Philip Davis, an English professor who has worked on the study with the university’s magnetic resonance centre, will tell a conference this week: “Serious literature acts like a rocket-booster to the brain.
"The research shows the power of literature to shift mental pathways, to create new thoughts, shapes and connections in the young and the staid alike."
Does listening to Mozart really boost your brainpower?
It is said that classical music could make children more intelligent, but when you look at the scientific evidence, the picture is more mixed.
You have probably heard of the Mozart effect. It’s the idea that if children or even babies listen to music composed by Mozart they will become more intelligent. A quick internet search reveals plenty of products to assist you in the task. Whatever your age there are CDs and books to help you to harness the power of Mozart’s music, but when it comes to scientific evidence that it can make you more clever, the picture is more mixed.
The phrase “the Mozart effect” was coined in 1991, but it is a study described two years later in the journal Nature that sparked real media and public interest about the idea that listening to classical music somehow improves the brain. It is one of those ideas that feels plausible. Mozart was undoubtedly a genius himself, his music is complex and there is a hope that if we listen to enough of it, a little of that intelligence might rub off on us.
The idea took off, with thousands of parents playing Mozart to their children, and in 1998 Zell Miller, the Governor of the state of Georgia in the US, even asked for money to be set aside in the state budget so that every newborn baby could be sent a CD of classical music. It’s not just babies and children who were deliberately exposed to Mozart’s melodies. When Sergio Della Sala, the psychologist and author of the book Mind Myths, visited a mozzarella farm in Italy, the farmer proudly explained that the buffalos were played Mozart three times a day to help them to produce better milk.
I’ll leave the debate on the impact on milk yield to farmers, but what about the evidence that listening to Mozart makes people more intelligent? Exactly what was it was that the authors of the initial study discovered that took public imagination by storm?
When you look back at the original paper, the first surprise is that the authors from the University of California, Irvine are modest in their claims and don’t even use the “Mozart effect” phrase in the paper. The second surprise is that it wasn’t conducted on children at all: it was in fact conducted with those stalwarts of psychological studies – young adult students. Only 36 students took part. On three occasions they were given a series of mental tasks to complete, and before each task, they listened either to ten minutes of silence, ten minutes of a tape of relaxation instructions, or ten minutes of Mozart’s sonata for two pianos in D major (K448).
The students who listened to Mozart did better at tasks where they had to create shapes in their minds. For a short time the students were better at spatial tasks where they had to look at folded up pieces of paper with cuts in them and to predict how they would appear when unfolded. But unfortunately, as the authors make clear at the time, this effect lasts for about fifteen minutes. So it’s hardly going to bring you a lifetime of enhanced intelligence.
Brain arousal
Nevertheless, people began to theorise about why it was that Mozart’s music in particular could have this effect. Did the complexity of music cause patterns of cortical firing in the brain similar to those associated with solving spatial puzzles?
More research followed, and a meta-analysis of sixteen different studies confirmed that listening to music does lead to a temporary improvement in the ability to manipulate shapes mentally, but the benefits are short-lived and it doesn’t make us more intelligent.
Then it began to emerge that perhaps Mozart wasn’t so special after all. In 2010 a larger meta-analysis of a greater number of studies again found a positive effect, but that other kinds of music worked just as well. One study found that listening to Schubert was just as good, and so was hearing a passage read out aloud from a Stephen King novel. But only if you enjoyed it. So, perhaps enjoyment and engagement are key, rather than the exact notes you hear.
Although we tend to associate the Mozart effect with babies and small children, most of these studies were conducted on adults, whose brains are of course at a very different stage of development. But in 2006 a large study was conducted in Britain involving eight thousand children. They listened either to ten minutes of Mozart’s String Quintet in D Major, a discussion about the experiment or to a sequence of three pop songs: Blur’s “Country House,” “Return of the Mack,” by Mark Morrison and PJ and Duncan’s “Stepping Stone”. Once again music improved the ability to predict paper shapes, but this time it wasn’t a Mozart effect, but a Blur effect. The children who listened to Mozart did well, but with pop music they did even better, so prior preference could come into it.
Whatever your musical choice, it seems that all you need to do a bit better at predictive origami is some cognitive arousal. Your mind needs to get a little more active, it needs something to get it going and that’s going to be whichever kind of music appeals to you. In fact, it doesn’t have to be music. Anything that makes you more alert should work just as well – doing a few star jumps or drinking some coffee, for instance.
There is a way in which music can make a difference to your IQ, though. Unfortunately it requires a bit more effort than putting on a CD. Learning to play a musical instrument can have a beneficial effect on your brain. Jessica Grahn, a cognitive scientist at Western University in London, Ontario says that a year of piano lessons, combined with regular practice can increase IQ by as much as three points.
So listening to Mozart won’t do you or your children any harm and could be the start of a life-long love of classical music. But unless you and your family have some urgent imaginary origami to do, the chances are that sticking on a sonata is not going to make you better at anything.
(Source: bbc.com)
Study shows cogntive benefit of lifelong bilingualism
Seniors who have spoken two languages since childhood are faster than single-language speakers at switching from one task to another, according to a study published in the January 9 issue of The Journal of Neuroscience. Compared to their monolingual peers, lifelong bilinguals also show different patterns of brain activity when making the switch, the study found.
The findings suggest the value of regular stimulating mental activity across the lifetime. As people age, cognitive flexibility — the ability to adapt to unfamiliar or unexpected circumstances — and related “executive” functions decline. Recent studies suggest lifelong bilingualism may reduce this decline — a boost that may stem from the experience of constantly switching between languages. However, how brain activity differs between older bilinguals and monolinguals was previously unclear.
In the current study, Brian T. Gold, PhD, and colleagues at the University of Kentucky College of Medicine, used functional magnetic resonance imaging (fMRI) to compare the brain activity of healthy bilingual seniors (ages 60-68) with that of healthy monolingual seniors as they completed a task that tested their cognitive flexibility. The researchers found that both groups performed the task accurately. However, bilingual seniors were faster at completing the task than their monolingual peers despite expending less energy in the frontal cortex — an area known to be involved in task switching.
“This study provides some of the first evidence of an association between a particular cognitively stimulating activity — in this case, speaking multiple languages on a daily basis — and brain function,” said John L. Woodard, PhD, an aging expert from Wayne State University, who was not involved with the study. “The authors provide clear evidence of a different pattern of neural functioning in bilingual versus monolingual individuals.”
The researchers also measured the brain activity of younger bilingual and monolingual adults while they performed the cognitive flexibility task.
Overall, the young adults were faster than the seniors at performing the task. Being bilingual did not affect task performance or brain activity in the young participants. In contrast, older bilinguals performed the task faster than their monolingual peers and expended less energy in the frontal parts of their brain.
“This suggests that bilingual seniors use their brains more efficiently than monolingual seniors,” Gold said. “Together, these results suggest that lifelong bilingualism may exert its strongest benefits on the functioning of frontal brain regions in aging.”
(Image: Harriet Russell)
Cognitive deficits from concussions still present after two months
The ability to focus and switch tasks readily amid distractions was compromised for up to two months following brain concussions suffered by high school athletes, according to a study at the University of Oregon.
Research team members, in an interview, said the discovery suggests that some athletes may need longer recovery periods than current practices dictate to lower the risk of subsequent concussions. Conventional wisdom, said lead author David Howell, a graduate student in the UO Department of Human Physiology, says that typical recovery from concussion takes seven to 10 days.
"The differences we detected may be a matter of milliseconds between a concussed person and a control subject, but as far as brain time goes that difference for a linebacker returning to competition too soon could mean the difference between another injury or successfully preparing to safely tackle an oncoming running back," Howell said.
The findings are based on cognitive exercises used five times over the two months with a pair of sensitive computer-based measuring tools — the attentional network test and the task-switching test. The study focused on the effects of concussions to the frontal region of the brain, which is responsible for working, or short-term, memory and executive function, said Li-Shan Chou, professor of human physiology and director of the UO Motion Analysis Laboratory.
The study was published online ahead of print by Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine.
Scientists explore the illusion of memory
A memory might seem like a permanent, precious essence carved deep into the circuits of the brain. But it is not. Instead, scientists are discovering that a memory changes every time you think about it.
"Every time you recall a memory, it becomes sensitive to disruption. Often that is used to incorporate new information into it." That’s the blunt assessment from one of the world’s leading experts on memory, Dr. Eric Kandel from Columbia University.
And that means our memories are not abstract snapshots stored forever in a bulging file in our mind, but rather, they’re a collection of brain cells — neurons that undergo chemical changes every time they’re engaged.
So when we think about something from the past, the memory is called up like a computer file, reviewed and revised in subtle ways, and then sent back to the brain’s archives, now modified slightly, updated, and changed.
As scientists increasingly understand the biological process of memory, they are also learning how to interrupt it, and that means they might one day be able to ease the pain of past trauma, or alter destructive habits and addictions, as though shaking an Etch A Sketch, erasing the scribbles on the mind, and starting fresh.
In his McGill University lab, researcher Karim Nader routinely erases the memory of his laboratory rats. But first he has to give them a memory and he does that by putting them in an isolation cubicle, playing a tone, and then delivering a small electrical shock to their feet.
Newborn memories of the “oohs” and “ahs” heard in the womb
Newborns are much more attuned to the sounds of their native language than first thought. In fact, these linguistic whizzes can up pick on distinctive sounds of their mother tongue while in utero, a new study has concluded.
Research led by Christine Moon, a professor of psychology at Pacific Lutheran University, shows that infants, only hours old showed marked interest for the vowels of a language that was not their mother tongue.
"We have known for over 30 years that we begin learning prenatally about voices by listening to the sound of our mother talking," Moon said. "This is the first study that shows we learn about the particular speech sounds of our mother’s language before we are born."
Before the study, the general consensus was that infants learned about the small parts of speech, the vowels and the consonants, postnatally. Moon added. “This study moves the measurable result of experience with individual speech sounds from six months of age to before birth,” she said. The findings were published in Acta Paediatrica.