Posts tagged psychology
Articles and news from the latest research reports.
Old schooled: You never stop learning like a child
The adult brain is far more malleable that we thought, and so learning can be child’s play if you know how.
Some 36-year-olds choose to collect vintage wine, vinyl records or sports memorabilia. For Richard Simcott, it is languages. His itch to learn has led him to study more than 30 foreign tongues – and he’s not ready to give up.
During our conversation in a London restaurant, he reels off sentences in Spanish, Turkish and Icelandic as easily as I can name the pizza and pasta on our menu. He has learned Dutch on the streets of Rotterdam, Czech in Prague and Polish during a house share with some architects. At home, he talks to his wife in fluent Macedonian.
What’s remarkable about Simcott isn’t just the number and diversity of languages he has mastered. It’s his age. Long before grey hairs appear and waistlines expand, the mind’s cogs are meant to seize up, making it difficult to pick up any new skill, be it a language, the flute, or archery. Even if Simcott had primed his mind for new languages while at school, he should have faced a steep decline in his abilities as the years went by – yet he still devours unfamiliar grammars and strange vocabularies to a high level. “My linguistic landscape is always changing,” he says. “If you’re school-aged, or middle-aged – I don’t think there’s a big difference.”
A decade ago, few neuroscientists would have agreed that adults can rival the learning talents of children. But we needn’t be so defeatist. The mature brain, it turns out, is more supple than anyone thought. “The idea that there’s a critical period for learning in childhood is overrated,” says Gary Marcus, a psychologist at New York University. What’s more, we now understand the best techniques to accelerate knowledge and skill acquisition in adults, so can perhaps unveil a few tricks of the trade of super-learners like Simcott. Whatever you want to learn, it’s never too late to charge those grey cells.
The idea that the mind fossilises as it ages is culturally entrenched. The phrase “an old dog will learn no tricks" is recorded in an 18th century book of proverbs and is probably hundreds of years older.
When researchers finally began to investigate the adult brain’s malleability in the 1960s, their results appeared to agree with the saying. Most insights came indirectly from studies of perception, which suggested that an individual’s visual abilities were capped at a young age. For example, restricting young animals’ vision for a few weeks after birth means they will never manage to see normally. The same is true for people born with cataracts or a lazy eye – repair too late, and the brain fails to use the eye properly for life. “For a very long time, it seemed that those constraints were set in stone after that critical period,” says Daphne Bavelier at the University of Rochester, New York.
These are extreme circumstances, of course, but the evidence suggested that the same neural fossilisation would stifle other kinds of learning. Many of the studies looked at language development – particularly in families of immigrants. While the children picked up new tongues with ease, their parents were still stuttering broken sentences. But if there is a critical period for foreign language learning, everyone should be affected equally; Simcott’s ability to master a host of languages should be as impossible as a dog playing the piano.
Bearing this in mind, Ellen Bialystok at York University in Toronto, Canada, recently turned to the US census records, which detailed the linguistic skills of more than 2 million Hispanic and Chinese immigrants. A “critical period” for learning a second language in infancy should have created a sharp difference between those who had moved country in early childhood and those who were uprooted in adolescence. In reality? “There was absolutely no discontinuity,” Bialystok says. Instead, she saw a very gradual decline with age among immigrants – which could reflect differences in environment as much as the adults’ rusty brain circuits. “People talk more slowly and clearly to children in short, simple sentences,” she says. “And the child’s entire social and educational network is organised around that language.”
Yet while Bialystok’s study suggested that adult brains are more pliable than had once been imagined, there was still the suspicion that children might have the edge in certain skills. Adult learners sometimes find it harder to learn to sing in tune, hit a home run or mimic an accent convincingly. At first glance, the problem might seem to lie in adults’ perception and motor skills. Learning involving these abilities differs from the acquisition of factual knowledge, because it needs us to rewire the eyes, ears and muscles.
It’s something that Marcus can identify with. At the age of 38, he devoted himself to learning the guitar, an experience he detailed in his book Guitar Zero. “My family’s initial response was laughter – but they soon saw I was making progress,” he says. Still, during his research, he attended a musical summer camp for 8 to 15-year-olds. He says he was quicker to catch on to the structure of songs, but his younger bandmates had better coordination and sense of pitch.
Yet the available evidence hints that children may not always be inherently better at such tasks. One study by Yang Zhang at the University of Minnesota in Minneapolis that focused on the acquisition of foreign accents in adults suggests we may simply be suffering from poor tuition. When the researchers gave them recordings that mimicked the exaggerated baby talk of cooing mothers, the adult learners progressed rapidly.
Nor do adults necessarily fumble over the intricate movements that are crucial for music or sport. When volunteers visiting Virginia Penhune's lab at Concordia University in Montreal, Canada, learned to press keys in a certain sequence, at certain times – essentially a boiled-down version of keyboard practice – the adults tended to outshine the younger volunteers.
During a more challenging test of hand-eye coordination, nearly 1000 volunteers of all age groups learned to juggle over a series of six training sessions. As you might expect, the senior citizens aged 60 to 80 began with some hesitation, but they soon caught up with the 30-year-olds and by the end of the trials all the adults were juggling more confidently than the 5 to 10-year-olds.
Old dogs, then, are much more adaptable than folklore would have it – and if we do have deficits, they aren’t insurmountable. The reason that children appear to be better learners may have more to do with their environment, and factors such as physical fitness (see “Faster body, faster mind”).
Indeed, many researchers believe that an adult’s lifestyle may be the biggest obstacle. “A child’s sole occupation is learning to speak and move around,” says Ed Cooke, a cognitive scientist who has won many memory contests. “If an adult had that kind of time to spend on attentive learning, I’d be very disappointed if they didn’t do a good job.”
A glut of free time and a carefree existence are out of reach for most of us, but there are other behaviours that boost children’s learning, and these habits can be easily integrated into even an adult’s schedule. For example, children are continually quizzed on what they know – and for good reason: countless studies have shown that testing doubles long-term recall, outperforming all other memory tactics. Yet most adults attempting to learn new skills will rely more on self-testing which, let’s be honest, happens less often.
That’s why Cooke developed a website, called Memrise, which helps take some of the pain out of testing and, crucially, can integrate learning into the adult day. It is designed to track your learning curve with cunningly timed tests that force you to retrieve the information just as you are about to forget it.
"Memrise engages your brain to the greatest possible extent," says Cooke, who has himself used the site to learn thousands of words of foreign vocabulary. Users can create their own courses – the topics range from art to zoology – and importantly, it is easy to load the site in the few spare minutes of your lunch break or while you are waiting for a train. Cooke also plans to launch a smartphone app.
What about tasks that involve perceptual learning or motor skills – like battling against a lifetime of tone deafness, or perfecting that golf swing? Here too, there are guiding principles that can help you rediscover the seemingly effortless learning of youth.
Adults can hamper progress with their own perfectionism: whereas children throw themselves into tasks, adults often agonise over the mechanics of the movements, trying to conceptualise exactly what is required. This could be one of our biggest downfalls. “Adults think so much more about what they are doing,” says Gabriele Wulf at the University of Nevada, Las Vegas. “Children just copy what they see.”
Wulf’s work over the past decade shows that you should focus on the outcome of your actions rather than the intricacies of the movements. She applies this finding in her own life: as a keen golfer, she has found it is better to think about the swing of the club, for instance, rather than the position of her hands. “I’m always trying to find where best to focus my attention,” she says. Similarly, if you are learning to sing, then you should concentrate on the tone of the voice, rather than on the larynx or the placement of the tongue. Study after study shows that simply shifting your mindset in this way accelerates your learning– perhaps by encouraging the subconscious, automatic movements that mark proficiency.
Misplaced conscientiousness may also lead adults to rely on overly rigid practice regimes that stifle long-term learning. The adult talent for perseverance, it seems, is not always a virtue. Left to their own devices, most people segment their sessions into separate blocks – when learning basketball, for instance, they may work on each shot in turn, perhaps because they feel a desire to master it. The approach may bring rapid improvements at first, but a host of studies have found that the refined technique is soon forgotten.
Instead, you do better to take a carousel approach, quickly rotating through the different skills to be practised without lingering too long on each one. Although the reason is still unclear, it seems that jumping between skills makes your mind work a little harder when applying what you’ve learned, helping you to retain the knowledge in the long term – a finding that has helped people improve in activities ranging from tennis and kayaking to pistol shooting.
Such an approach might not be to everyone’s taste – with intricate skills, it might feel like you are making no progress. But even if you do revert to stints of lengthy practice, you can still reap some of the same benefits by occasionally trying out your skills in an unfamiliar situation. In tennis, you might move to a different part of the court for a couple of serves before returning to the regular position; while playing scales on a musical instrument, you might switch hands temporarily. According to work by Arnaud Boutin at the Leibniz Research Centre for Working Environment and Human Factors in Dortmund, Germany, venturing out of your comfort zone in this way helps to ensure that you improve your overall performance rather than confining your progress to the single task at hand. “Otherwise, the longer you practise, the harder it becomes to transfer the skills that you’ve learned to new situations,” says Boutin.
If none of that helps you learn like a child, simply adopting the arrogance of youth may do no harm. “As we get older, we lose our confidence, and I’m convinced that has a big impact on performance,” says Wulf. To test the assumption, she recently trained a small group of people to pitch a ball. While half were given no encouragement, she offered the others a sham test, rigged to demonstrate that their abilities were above average. They learned to pitch on target with much greater accuracy than those who didn’t get an ego boost.
Whether your itch to learn will ever match Simcott’s appetite for foreign languages is another matter. “What I do – it’s like an extreme sport. There’s no need to learn that many languages,” he says. He has recently turned to Chinese, and has no plans to stop after that. “I’m like a linguistic butterfly. There’s always another, really far away, that suddenly feels appealing.”
Still, embrace the idea that your mind is as capable as Simcott’s, and the lure of extreme learning might take hold of you too.
-by David Robson, New Scientist
Hormone levels may provide key to understanding psychological disorders in women
Women at a particular stage in their monthly menstrual cycle may be more vulnerable to some of the psychological side-effects associated with stressful experiences, according to a study from UCL.
The results suggest a monthly window of opportunity that could potentially be targeted in efforts to prevent common mental health problems developing in women. The research is the first to show a potential link between psychological vulnerability and the timing of a biological cycle, in this case ovulation.
A common symptom of mood and anxiety problems is the tendency to experience repetitive and unwanted thoughts. These ‘intrusive thoughts’ often occur in the days and weeks after a stressful experience.
In this study, the researchers examined whether the effects of a stressful event are linked to different stages of the menstrual cycle. The participants were 41 women aged between 18 and 35 who had regular menstrual cycles and were not using the pill as a form of contraception. Each woman watched a 14-minute stressful film containing death or injury and provided a saliva sample so that hormone levels could be assessed. They were then asked to record instances of unwanted thoughts about the video over the following days.
“We found that women in the ‘early luteal’ phase, which falls roughly 16 to 20 days after the start of their period, had more than three times as many intrusive thoughts as those who watched the video in other phases of their menstrual cycle,” explains author Dr Sunjeev Kamboj, Lecturer in UCL’s Department of Clinical, Educational and Health Psychology.
“This indicates that there is actually a fairly narrow window within the menstrual cycle when women may be particularly vulnerable to experiencing distressing symptoms after a stressful event.”
The findings could have important implications for mental health problems and their treatment in women who have suffered trauma.
“Asking women who have experienced a traumatic event about the time since their last period might help identify those at greatest risk of developing recurring symptoms similar to those seen in psychological disorders such as depression and post-traumatic stress disorder (PTSD),” said Dr Kamboj.
“This work might have identified a useful line of enquiry for doctors, helping them to identify potentially vulnerable women who could be offered preventative therapies,” continued Dr Kamboj.
“However, this is only a first step. Although we found large effects in healthy women after they experienced a relatively mild stressful event, we now need to see if the same pattern is found in women who have experienced a real traumatic event. We also need further research to investigate how using the contraceptive pill affects this whole process.”
(Source: ucl.ac.uk)
IQ Predicted by the Brain’s Ability to Filter Visual Motion
A brief visual task can predict IQ, according to a new study.
This surprisingly simple exercise measures the brain’s unconscious ability to filter out visual movement. The study shows that individuals whose brains are better at automatically suppressing background motion perform better on standard measures of intelligence.
The test is the first purely sensory assessment to be strongly correlated with IQ and may provide a non-verbal and culturally unbiased tool for scientists seeking to understand neural processes associated with general intelligence.
"Because intelligence is such a broad construct, you can’t really track it back to one part of the brain," says Duje Tadin, a senior author on the study and an assistant professor of brain and cognitive sciences at the University of Rochester. "But since this task is so simple and so closely linked to IQ, it may give us clues about what makes a brain more efficient, and, consequently, more intelligent."
The unexpected link between IQ and motion filtering was reported online in the Cell Press journal Current Biology on May 23 by a research team lead by Tadin and Michael Melnick, a doctoral candidate in brain and cognitive sciences at the University of Rochester.
In the study, individuals watched brief video clips of black and white bars moving across a computer screen. Their sole task was to identify which direction the bars drifted: to the right or to the left. The bars were presented in three sizes, with the smallest version restricted to the central circle where human motion perception is known to be optimal, an area roughly the width of the thumb when the hand is extended. Participants also took a standardized intelligence test.
As expected, people with higher IQ scores were faster at catching the movement of the bars when observing the smallest image. The results support prior research showing that individuals with higher IQs make simple perceptual judgments swifter and have faster reflexes. “Being ‘quick witted’ and ‘quick on the draw’ generally go hand in hand,” says Melnick.
But the tables turned when presented with the larger images. The higher a person’s IQ, the slower they were at detecting movement. “From previous research, we expected that all participants would be worse at detecting the movement of large images, but high IQ individuals were much, much worse,” says Melnick. That counter-intuitive inability to perceive large moving images is a perceptual marker for the brain’s ability to suppress background motion, the authors explain. In most scenarios, background movement is less important than small moving objects in the foreground. Think about driving in a car, walking down a hall, or even just moving your eyes across the room. The background is constantly in motion.
The key discovery in this study is how closely this natural filtering ability is linked to IQ. The first experiment found a 64 percent correlation between motion suppression and IQ scores, a much stronger relationship than other sensory measures to date. For example, research on the relationship between intelligence and color discrimination, sensitivity to pitch, and reaction times have found only a 20 to 40 percent correlation. “In our first experiment, the effect for motion was so strong,” recalls Tadin, “that I really thought this was a fluke.”
So the group tried to disprove the findings from the initial 12-participant study conducted while Tadin was at Vanderbilt University working with co-author Sohee Park, a professor of psychology. They reran the experiment at the University of Rochester on a new cohort of 53 subjects, administering the full IQ test instead of an abbreviated version and the results were even stronger; correlation rose to 71 percent. The authors also tested for other possible explanations for their findings.
For example, did the surprising link to IQ simply reflect a person’s willful decision to focus on small moving images? To rule out the effect of attention, the second round of experiments randomly ordered the different image sizes and tested other types of large images that have been shown not to elicit suppression. High IQ individuals continued to be quicker on all tasks, except the ones that isolated motion suppression. The authors concluded that high IQ is associated with automatic filtering of background motion.
"We know from prior research which parts of the brain are involved in visual suppression of background motion. This new link to intelligence provides a good target for looking at what is different about the neural processing, what’s different about the neurochemistry, what’s different about the neurotransmitters of people with different IQs," says Tadin.
The relationship between IQ and motion suppression points to the fundamental cognitive processes that underlie intelligence, the authors write. The brain is bombarded by an overwhelming amount of sensory information, and its efficiency is built not only on how quickly our neural networks process these signals, but also on how good they are at suppressing less meaningful information. “Rapid processing is of little utility unless it is restricted to the most relevant information,” the authors conclude.
The researchers point out that this vision test could remove some of the limitations associated with standard IQ tests, which have been criticized for cultural bias. “Because the test is simple and non-verbal, it will also help researchers better understand neural processing in individuals with intellectual and developmental disabilities,” says co-author Loisa Bennetto, an associate professor of psychology at the University of Rochester.
Depression Linked to Telomere Enzyme, Aging, Chronic Disease
The first symptoms of major depression may be behavioral, but the common mental illness is based in biology — and not limited to the brain.
In recent years, some studies have linked major, long-term depression with life-threatening chronic disease and with earlier death, even after lifestyle risk factors have been taken into account.
Now a research team led by Owen Wolkowitz, MD, professor of psychiatry at UC San Francisco, has found that within cells of the immune system, activity of an enzyme called telomerase is greater, on average, in untreated individuals with major depression. The preliminary findings from his latest, ongoing study was reported Wednesday at the annual meeting of the American Psychiatric Association in San Francisco.
Telomerase is an enzyme that lengthens protective end caps on the chromosomes’ DNA, called telomeres. Shortened telomeres have been associated with earlier death and with chronic diseases in population studies.
The heightened telomerase activity in untreated major depression might represent the body’s attempt to fight back against the progression of disease, in order to prevent biological damage in long-depressed individuals, Wolkowitz said.
The researchers made another discovery that may suggest a protective role for telomerase. Using magnetic resonance imaging (MRI), they found that, in untreated, depressed study participants, the size of the hippocampus, a brain structure that is critical for learning and memory, was associated with the amount of telomerase activity measured in the white blood cells. Such an association at a single point in time cannot be used to conclude that there is a cause-and-effect relationship with telomerase helping to protect the hippocampus, but it is plausible, Wolkowitz said.
Telomerase Activity and Antidepressants
Remarkably, the researchers also found that the enzyme’s activity went up when some patients began taking an antidepressant. In fact, depressed participants with lower telomerase activity at baseline — as well as those in whom enzyme activity increased the most with treatment — were the most likely to become less depressed with treatment.
“Our results are consistent with the beneficial effect of telomerase when it is boosted in animal studies, where it has been associated with the growth of new nerve cells in the hippocampus and with antidepressant-like effects, evidenced by increased exploratory behavior,” Wolkowitz said. He cautions that his new findings are preliminary due to the small size of the study and must be confirmed through further research.
The researchers also measured telomere length in the same immune cells. Only very chronically depressed individuals showed telomere shortening, Wolkowitz said.
“The longer people had been depressed, the shorter their telomeres were,” he said. “Shortened telomere length has been previously demonstrated in major depression in most, but not all, studies that have examined it. The duration of depression may be a critical factor.”
Ongoing Study
The 20 depressed participants enrolled in the study had been untreated for at least six weeks and had an average lifetime duration of depression of about 13 years. After baseline evaluation and laboratory measures, 16 of the depressed participants were treated with sertraline, a member of the most popular class of antidepressants, the serotonin-selective-reuptake-inhibitors (SSRIs), and then evaluated again after eight weeks. There were 20 healthy participants who served as controls.
The ongoing study still is accepting depressed participants who are not now taking antidepressants.
Wolkowitz’s team also studies chronic inflammation and the biochemical phenomenon of oxidative stress, which he said have often been reported in major depression. Wolkowitz is exploring the hypothesis that inflammation and oxidative stress play a role in telomere shortening and accelerated aging in depression.
“New insights into the mechanisms of these processes may well lead to new treatments — both pharmacological and behavioral — that will be distinctly different from the current generation of drugs prescribed to treat depression,” he said. “Additional studies might lead to simple blood tests that can measure accelerated immune-cell aging.”
(Source: ucsf.edu)
Brain can be trained in compassion
Until now, little was scientifically known about the human potential to cultivate compassion — the emotional state of caring for people who are suffering in a way that motivates altruistic behavior.
A new study by researchers at the Center for Investigating Healthy Minds at the Waisman Center of the University of Wisconsin-Madison shows that adults can be trained to be more compassionate. The report, recently published online in the journal Psychological Science, is the first to investigate whether training adults in compassion can result in greater altruistic behavior and related changes in neural systems underlying compassion.
"Our fundamental question was, ‘Can compassion be trained and learned in adults? Can we become more caring if we practice that mindset?’" says Helen Weng, a graduate student in clinical psychology and lead author of the paper. "Our evidence points to yes."
In the study, the investigators trained young adults to engage in compassion meditation, an ancient Buddhist technique to increase caring feelings for people who are suffering. In the meditation, participants envisioned a time when someone has suffered and then practiced wishing that his or her suffering was relieved. They repeated phrases to help them focus on compassion such as, “May you be free from suffering. May you have joy and ease.”
Participants practiced with different categories of people, first starting with a loved one, someone whom they easily felt compassion for like a friend or family member. Then, they practiced compassion for themselves and, then, a stranger. Finally, they practiced compassion for someone they actively had conflict with called the “difficult person,” such as a troublesome coworker or roommate.
"It’s kind of like weight training," Weng says. "Using this systematic approach, we found that people can actually build up their compassion ‘muscle’ and respond to others’ suffering with care and a desire to help."
Compassion training was compared to a control group that learned cognitive reappraisal, a technique where people learn to reframe their thoughts to feel less negative. Both groups listened to guided audio instructions over the Internet for 30 minutes per day for two weeks. “We wanted to investigate whether people could begin to change their emotional habits in a relatively short period of time,” says Weng.
The real test of whether compassion could be trained was to see if people would be willing to be more altruistic — even helping people they had never met. The research tested this by asking the participants to play a game in which they were given the opportunity to spend their own money to respond to someone in need (called the “Redistribution Game”). They played the game over the Internet with two anonymous players, the “Dictator” and the “Victim.” They watched as the Dictator shared an unfair amount of money (only $1 out of $10) with the Victim. They then decided how much of their own money to spend (out of $5) in order to equalize the unfair split and redistribute funds from the Dictator to the Victim.
"We found that people trained in compassion were more likely to spend their own money altruistically to help someone who was treated unfairly than those who were trained in cognitive reappraisal," Weng says.
"We wanted to see what changed inside the brains of people who gave more to someone in need. How are they responding to suffering differently now?" asks Weng. The study measured changes in brain responses using functional magnetic resonance imaging (fMRI) before and after training. In the MRI scanner, participants viewed images depicting human suffering, such as a crying child or a burn victim, and generated feelings of compassion towards the people using their practiced skills. The control group was exposed to the same images, and asked to recast them in a more positive light as in reappraisal.
The researchers measured how much brain activity had changed from the beginning to the end of the training, and found that the people who were the most altruistic after compassion training were the ones who showed the most brain changes when viewing human suffering. They found that activity was increased in the inferior parietal cortex, a region involved in empathy and understanding others. Compassion training also increased activity in the dorsolateral prefrontal cortex and the extent to which it communicated with the nucleus accumbens, brain regions involved in emotion regulation and positive emotions.
"People seem to become more sensitive to other people’s suffering, but this is challenging emotionally. They learn to regulate their emotions so that they approach people’s suffering with caring and wanting to help rather than turning away," explains Weng.
Compassion, like physical and academic skills, appears to be something that is not fixed, but rather can be enhanced with training and practice. “The fact that alterations in brain function were observed after just a total of seven hours of training is remarkable,” explains UW-Madison psychology and psychiatry professor Richard J. Davidson, founder and chair of the Center for Investigating Healthy Minds and senior author of the article.
"There are many possible applications of this type of training," Davidson says. "Compassion and kindness training in schools can help children learn to be attuned to their own emotions as well as those of others, which may decrease bullying. Compassion training also may benefit people who have social challenges such as social anxiety or antisocial behavior."
Weng is also excited about how compassion training can help the general population. “We studied the effects of this training with healthy participants, which demonstrated that this can help the average person. I would love for more people to access the training and try it for a week or two — what changes do they see in their own lives?”
Both compassion and reappraisal trainings are available on the Center for Investigating Healthy Minds’ website. “I think we are only scratching the surface of how compassion can transform people’s lives,” says Weng.
(Source: news.wisc.edu)
Waiting for a sign? Researchers find potential brain ‘switch’ for new behavior
You’re standing near an airport luggage carousel and your bag emerges on the conveyor belt, prompting you to spring into action. How does your brain make the shift from passively waiting to taking action when your bag appears?
A new study from investigators at the University of Michigan and Eli Lilly may reveal the brain’s “switch” for new behavior. They measured levels of a neurotransmitter called acetylcholine, which is involved in attention and memory, while rats monitored a screen for a signal. At the end of each trial, the rat had to indicate if a signal had occurred.
Researchers noticed that if a signal occurred after a long period of monitoring or “non-signal” processing, there was a spike in acetylcholine in the rat’s right prefrontal cortex. No such spike occurred for another signal occurring shortly afterwards.
"In other words, the increase in acetylcholine seemed to activate or ‘switch on’ the response to the signal, and to be unnecessary if that response was already activated," said Cindy Lustig, one of the study’s senior authors and an associate professor in the U-M Department of Psychology.
The researchers repeated the study in humans using functional magnetic resonance imaging (fMRI), which measures brain activity, and also found a short increase in right prefrontal cortex activity for the first signal in a series.
To connect the findings between rats and humans, they measured changes in oxygen levels, similar to the changes that produce the fMRI signal, in the brains of rats performing the task.
They again found a response in the right prefrontal cortex that only occurred for the first signal in a series. A follow-up experiment showed that direct stimulation of brain tissue using drugs that target acetylcholine receptors could likewise produce these changes in brain oxygen.
Together, the studies’ results provide some of the most direct evidence, so far, linking a specific neurotransmitter response to changes in brain activity in humans. The findings could guide the development of better treatments for disorders in which people have difficulty switching out of current behaviors and activating new ones. Repetitive behaviors associated with obsessive-compulsive disorder and autism are the most obvious examples, and related mechanisms may underlie problems with preservative behavior in schizophrenia, dementia and aging.
The findings appear in the current issue of Journal of Neuroscience.
UCSB Study Shows Where Scene Context Happens in our Brain
In a remote fishing community in Venezuela, a lone fisherman sits on a cliff overlooking the southern Caribbean Sea. This man –– the lookout –– is responsible for directing his comrades on the water, who are too close to their target to detect their next catch. Using abilities honed by years of scanning the water’s surface, he can tell by shadows, ripples, and even the behavior of seabirds, where the fish are schooling, and what kind of fish they might be, without actually seeing the fish. This, in turn, changes where the boats go, and how the men fish.
Though a seemingly simple and intuitive strategy, the lookout’s visual search function –– a process that takes mere seconds for the human brain –– is still something that a computer, despite technological advances, can’t do as accurately.
"Behind what seems to be automatic is a lot of sophisticated machinery in our brain," said Miguel Eckstein, professor in UC Santa Barbara’s Department of Psychological & Brain Sciences. "A great part of our brain is dedicated to vision."
Over the millennia of human evolution, our brains developed a pattern of search based largely on environmental cues and scene context. It’s an ability that has not only helped us find food and avoid danger in humankind’s earliest days, but continues to aid us today, in tasks as banal as driving to work, or shopping; or as specialized as reading X-rays.
Where this –– the search for objects using scene and other objects –– occurs in the brain is little understood, and is for the first time discussed in the paper, “Neural Representations of Contextual Guidance in Visual Search of Real-World Scenes,” published recently in the Journal of Neuroscience.
The researchers flashed hundreds images of indoor and outdoor scenes before observers, and instructed them to search for certain objects that were consistent with those scenes. Half of the images, however, did not contain the target object. During the trials, the subjects were asked to indicate whether the target object was present in the scene.
The researchers were particularly interested in the images that did not contain the target. Another measure was taken to determine where subjects expected specific objects to be in target-absent scenes. Invariably, the subjects would indicate similar areas: If presented with a living room scene and told to look for a clock or a painting, they would indicate the wall; if shown a photo of a bathroom and told to indicate where to expect a hand soap or toothbrush, they would indicate the sink.
The searched object’s contextual location in the scenes, according to the study, is represented in the area called the lateral occipital complex (LOC), a place that corresponds roughly to the lower back portion of the head, toward the side. This area, according to Eckstein, has the ability to account for other objects in the scene that often appear in close spatial proximity with the searched object –– something computers are only recently being taught to do.
"So, if you’re looking for a computer mouse on a cluttered desk, a machine would be looking for things shaped like a mouse. It might find it, but it might see other objects of similar shape, and classify that as a mouse," Eckstein said. Computer vision systems might also not associate their target with specific locations or other objects. So, to a machine, the floor is just as likely a place for a mouse as a desk.
The LOC, on the other hand, would contain the information the brain needs to direct a person’s attention and gaze first toward the most likely place that a mouse might be, such as on top of the desk, or near the keyboard. From there, other visual parts of the brain go to work, searching for particular characteristics, or determining the target’s presence.
So strong is the scene context in biasing search, said Eckstein, that if another similar-looking object was placed in the location where the mouse is likely to be, and that scene briefly flashed before your eyes, you would likely –– erroneously –– interpret that object as the mouse.
While scene context information has been found highly active in the LOC, other visual areas of the brain are also influenced by context to certain degrees, including the interparietal sulcus, located near the top of the head; and the retrosplenial cortex, found in the brain’s interior.
"Since contextual guidance is a critical strategy that allows humans to rapidly find objects in scenes, studying the brain areas involved in normal humans might help us to gain a better understanding of neural areas involved in those with visual search deficits, such as brain-damaged patients and the elderly," Eckstein said. "Also, a large component of becoming an expert searcher –– like radiologists or fishermen –– is exploiting contextual relationships to search. Thus, understanding the neural basis of contextual guidance might allow us to gain a better understanding about what brain areas are critical to gain search expertise."
Practice makes perfect? Not so much
Turns out, that old “practice makes perfect” adage may be overblown.
New research led by Michigan State University’s Zach Hambrick finds that a copious amount of practice is not enough to explain why people differ in level of skill in two widely studied activities, chess and music.
In other words, it takes more than hard work to become an expert. Hambrick, writing in the research journal Intelligence, said natural talent and other factors likely play a role in mastering a complicated activity.
“Practice is indeed important to reach an elite level of performance, but this paper makes an overwhelming case that it isn’t enough,” said Hambrick, associate professor of psychology.
The debate over why and how people become experts has existed for more than a century. Many theorists argue that thousands of hours of focused, deliberate practice is sufficient to achieve elite status.
Hambrick disagrees.
“The evidence is quite clear,” he writes, “that some people do reach an elite level of performance without copious practice, while other people fail to do so despite copious practice.”
Hambrick and colleagues analyzed 14 studies of chess players and musicians, looking specifically at how practice was related to differences in performance. Practice, they found, accounted for only about one-third of the differences in skill in both music and chess.
So what made up the rest of the difference?
Based on existing research, Hambrick said it could be explained by factors such as intelligence or innate ability, and the age at which people start the particular activity. A previous study of Hambrick’s suggested that working memory capacity – which is closely related to general intelligence – may sometimes be the deciding factor between being good and great.
While the conclusion that practice may not make perfect runs counter to the popular view that just about anyone can achieve greatness if they work hard enough, Hambrick said there is a “silver lining” to the research.
“If people are given an accurate assessment of their abilities and the likelihood of achieving certain goals given those abilities,” he said, “they may gravitate toward domains in which they have a realistic chance of becoming an expert through deliberate practice.”
China’s One-Child Policy Affects Personality
In 1979 China instituted the one-child policy, which limited every family to just one offspring in a controversial attempt to reduce the country’s burgeoning population. The strictly enforced law had the desired effects: in 2011 researchers estimated that the policy prevented 400 million births. In a new study in Science, researchers find that it has also caused China’s so-called little emperors to be more pessimistic, neurotic and selfish than their peers who have siblings.
Psychologist Xin Meng of the Australian National University in Canberra and her colleagues recruited 421 Chinese young adults born between 1975 and 1983 from around Beijing for a series of surveys and tests that evaluated a variety of psychological traits, such as trustworthiness and optimism. Almost all the participants born after 1979 were only children compared with about one fifth of those born before 1979. The study participants born after the policy went into effect were found to be both less trusting and less trustworthy, less inclined to take risks, less conscientious and optimistic, and less competitive than those born a few years earlier.
“Because of the one-child policy, parents are less likely to teach their child to be imaginative, trusting and unselfish,” Meng says. Without siblings, she notes, the need to share may not be emphasized, which could help explain these findings.
Only children in other parts of the world, however, do not show such striking differences from their peers. Toni Falbo, a social psychologist at the University of Texas at Austin, who was not involved in the study, suggests that larger social forces in China also probably contributed to these results. “There’s a lot of pressure being placed on [Chinese] parents to make their kid the best possible because they only had one,” Falbo says. These types of pressures could harm anyone, even if they had siblings, she says.
Whatever its cause, the personality profile of China’s little emperors may be troubling to a nation hoping to continue its ascent in economic prosperity. The traits marred by the one-child policy, the study authors point out, are exactly those needed in leaders and entrepreneurs.
(Source: scientificamerican.com)
Bats Can Recognize Each Other’s Voices
If bats ever used a cell phone, they could forgo the version with caller ID: The mammals can identify each other by their voices, a new study says.
Bats aren’t the only mammals to use voice recognition—people do it, too. Even in the days before caller ID, a simple “Hi, it’s me,” from a close friend or loved one was usually enough to figure out who’s on the other end. Recognizing a person by voice, however, requires previous knowledge: We can’t identify a stranger on the phone by voice alone because we have never met them before.
People can, however, discriminate between a familiar voice and an unfamiliar one, even if they’ve never met the other person. We can also distinguish between two individuals by voice alone even if we’ve never met them before.
Hanna Kastein and colleagues at the University of Veterinary Medicine in Hannover, Germany, wanted to know whether bats could perform these same tasks.
“Bats are totally interesting mammals to study voice perception since they are dependent on their vocalizations for orientation and communication due to their nocturnal lifestyle. In addition, they are socially living animals that frequently communicate acoustically with other members of their species,” Kastein said.
Besides their social lifestyles, bats and people share a number of physical characteristics. Both produce sounds using a combination of the larynx, vocal cords, and nasal cavities. These structures work together with an animal’s physical makeup to produce an individual’s unique voice.
“In stressful situations, voices become higher pitched, or ‘squeaky,’ in bats as in humans. Also, each individual bat has a slightly different morphology, and thus its voice sounds different from any other individual, just as voices in humans differ individually,” Kastein said.
You Had Me at Hello
Kastein and colleagues wanted to know whether bats could use vocal calls to identify individuals with which they shared a roost, and whether they could use these same calls to distinguish between two different individuals.
The researchers worked with the greater false vampire bat (Megaderma lyra) because the species has a rich array of calls that it uses in several contexts.
The team observed two groups of bats kept in separate artificial roosts for two months. They hypothesized that bats that had the most body contact while roosting would form the closest relationships. Kastein and colleagues then recorded various vocal calls from both groups of bats.
When Kastein played the recording of a vocal call over a loudspeaker, bats in both roosts universally turned their heads toward the speaker regardless of whether the call was from a bat with which they had close body contact, a bat from the same roost, or a bat from the other roost.
Given that the artificial roosts had much lower rates of vocal calls, due to the lack of stimuli, the researchers thought that this response could be due to the novelty of hearing any type of vocalization.
Discriminating Bat
So the team did a second set of experiments in which they had a bat listen to the call of their “friend” until the call didn’t create any type of behavioral response, such as turning the head. This means the listening bat had become habituated to the call, according to the study, published recently in the journal Animal Cognition.
Then, the scientists alternated playing a vocalization of the bat friend with that of an unfamiliar bat. The listening bats were significantly more likely to turn their heads toward the call of their friend—indicating both that they recognized their friend and that they could distinguish between individual vocalizations.
“In our study, we found that the … false vampire bat is able to discriminate between different voices, including both known or unknown individuals,” Kastein noted.
“However, to what extent bats are able to label an unknown bat as unknown, we cannot say.” She suspects that in real life, recognizing other bats by their voices is aided by smell and, to a lesser extent, vision.