It’s a movie cliche: the moment when the lost traveler intersects a set of footprints, only to realize that the prints where made by his very own boot soles. The hero then realizes, with plunging heart, that he’s been walking in circles while trying to walk a straight course through the featureless expanse. Now a small study has shown that the cliche is true. Without the sun, a compass or a landmark, people trying to follow a straight course through a forest or a desert ended up back where they started [HealthDay News].
In the first experiment, six participants tried to follow a straight course through a forest in Germany, in an area where the land is flat and the trees quickly begin to look alike. The two subjects who walked on a sunny day stayed on a fairly straight course (as tracked by a GPS device), except for the first 15 minutes when the sun was behind the clouds. But the four who walked on an overcast day repeatedly traveled in circles, sometimes crossing their own paths after only 10 minutes. Says lead researcher Jan Souman: “They didn’t really believe when we showed them afterwards…. I think that’s certainly a point to take away, people may feel very confident about the direction where they’re going but it’s not certain” [ABC News].
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Chronically stressed rats make decisions based on habit, new research has shown, even when those habits no longer produce the maximum benefit. Researchers say the stressed out rats’ inability to adapt to changing circumstances seems similar to the human response to chronic stress. How often do we talk about burned-out people who are just going through the motions? [ABC News]
In the study, published in Science, the researchers subjected the rats to several tests. In one experiment, the rats were trained to press a lever to receive a reward (either food pellets or sucrose). After two weeks of training, they were given full access to the reward and allowed to consume as much as they desired. When presented with the lever again, control animals stopped pressing the lever, but stressed animals didn’t. If you get the dessert for free, [study coauthor Rui] Costa said, there’s no need to work for it. “That’s what control animals do,” but stressed animals work anyway [The Scientist].
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It’s the date of your dreams. As the waiter pours the wine, you’re pouring on the charm. Then it happens: You uncork the most embarrassing, oafish and inappropriate thing you’ve ever uttered. And as a look of pure get-me-out-of-here takes hold on your date’s face, you think, “How on Earth could I have said that!” [Toronto Star] Now, Harvard psychologist Daniel Wegner suggests that the embarrassing phenomenon of putting your foot in your mouth comes from your brain’s overzealous attempt to avoid social gaffes.
Wegner describes accumulating evidence that suggests many of our embarrassing moments are the result of miscommunications between conscious and unconscious mental processes [LiveScience]. Sitting across the table from your date, you may consciously run through the worst possible things you could say: an insulting remark regarding her ethnicity, perhaps, or an inappropriate sexual allusion. While your conscious mind then moves on to other subjects, the unconscious mind begins a ceaseless scan for those unwelcome thoughts. It’s that monitoring mechanism that can lead to trouble.
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A noisy Italian disco may not seem like a conducive location for scientific experiments, but for a couple of researchers investigating hearing and language processing it was perfect. The undercover scientists studied clubbers who were trying to talk while the music was pumping, and found that they showed a decided preference for speaking into each other’s right ears. What’s more, when the researchers approached clubbers with a request for a cigarette, they found the unwitting test subjects were much more likely to comply if the petition was made in the right ear.
Previous lab studies have also suggested that humans tend to have a preference for listening to verbal input with their right ears and that given stimulus in both ears, they’ll privilege the syllables that went into the right ear. Brain scientists hypothesize that the right ear auditory stream receives precedence in the left hemisphere of the brain, where the bulk of linguistic processing is carried out [Wired.com]. Researchers say this bias holds true for both lefties and righties.
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Rats in laboratory tests learned to gamble based on a system of punishments and rewards, strategizing like human gamblers. And when researchers tweaked the animals’ brain chemistry to mimic that of humans with a gambling addiction, the mice began taking risks like pathological gamblers, according to a study published in the journal Neuropsychopharmacology.
To create this animal model of gambling addiction, researchers created a system in which options that could bring greater rewards also could yield stronger punishment. In this case, however, instead of gambling for money, the rats aimed to get as many sugar pellets as possible. The rodents were placed in specially built boxes whose walls incorporated four “response holes.” Each opening was associated with a possibility of earning treats – from one up to four, depending on the aperture chosen. When an animal poked its snout into a hole, the movement would break an infra-red light across the opening, signaling a computer with a “probabilistic” reward-punishment schedule to assign a pellet win or a “timeout” loss. Playing against the clock, the rats had only 30 minutes to accumulate as many sugar pellets as they could [The Canadian Press].
The rats quickly caught on that by choosing the openings that offered the greatest number of pellets, they also risked the longest time-outs during which they could not play the game. The test was based on an evaluation for decision-making in humans called the Iowa Gambling Test. In that game, there are some “bad” decks of cards that offer high rewards and punishments, and other “good” decks that offer lesser rewards and punishments.
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Deciding to reach out your arm and grab something and physically doing it are very different things, a fascinating new study has shown, and are controlled by two distinct regions of the brain. Researchers found that by directly stimulating a brain region called the parietal cortex, they could give test subjects the strong urge to move various body parts, like arms and lips. An even stronger jolt produced a false belief that they actually had moved. On the flipside of the experiment, when researchers stimulated a different part of the brain, the premotor cortex, the subject jerked or twitched, but wasn’t aware of it. The findings suggest that “we need intention to be aware of what we are doing,” says [study coauthor Angela] Sirigu. The brain’s intention and its prediction of what will result from carrying out that intention create our experience of having moved, she says [ScienceNOW Daily News].
The unusual study took advantage of a common operating room practice. As part of their preparation for surgery, neurosurgeons sometimes electrically stimulate the brains of their patients, who are awake under local anesthetic, to map the brain and minimize surgical complications [ScienceNOW Daily News]. In the case of this new study, published in Science, the patients were undergoing operations for brain tumors, but had agreed to take part in an experiment before the main surgery commenced. In all but one of the seven cases, the cancer was located far from the brain regions being stimulated.
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When people are given “expert” financial advice, the decision-making parts of the brain shut down, a small new study has found. Brain scans of 24 volunteers showed that claims of expertise were found to suppress activity in the neural circuit linked to decision-making [Telegraph]. “It’s almost as if the brain stops trying to make a decision on its own” [CNN], said lead researcher Gregory Berns.
In the study, college students connected to MRI scanners were asked to choose between taking a guaranteed payment and gambling for a higher payoff. Some made the decision on their own, while others were given written advice that they were told came from an economist who counsels the U.S. Federal Reserve. The advice was intentionally poor, and urged students to accept the guaranteed small payments rather than gamble with good odds for a much higher return. When thinking for themselves, students showed activity in their anterior cingulate cortex and dorsolateral prefrontal cortex — brain regions associated with making decisions and calculating probabilities. When given advice from [the economist], activity in those regions flat lined [Wired]. The students who received the advice tended to follow it.
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Brain scans can pick up the distinct pattern of brain waves that occur when a person’s attention lapses, and can therefore predict when the person is about to make a mistake, according to a small new study.
Using magnetoencephalography (MEG), researchers monitored the oscillations in brain activity for 14 test subjects. Each student was asked to take part in monotonous test in which a random number from one to nine flashed on a screen every two seconds, and they were asked to tap a button as soon as any number except five appeared. The test was so boring that even when a five showed up, the subjects spontaneously hit the button an average of 40% of the time [BBC News].
About a second before they committed the error, brain waves in two regions spiked: alpha wave activity in the occipital region was about 25 percent greater than usual, and in the sensorimotor cortex there was a corresponding increase in the brain’s mu wave activity.
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To figure out whether you’ll like the restaurant around the corner or that new guy in accounting or a vacation in Madrid, or just about anything else you’ve never personally experienced, try asking a stranger who has [Time]. That stranger is likely to predict, better than you can yourself, how much enjoyment you’ll get from that new experience (or the guy in accounting).
Previous research has shown that people tend to overestimate how disappointed or unhappy they will be after a perceived negative event, such as being denied a promotion, as well as how happy they will feel after positive events, like winning a prize. Building on that knowledge, psychology professor Daniel Gilbert conducted experiments in which he asked people to predict how much they’d enjoy a future event that they knew nothing about—except how much a total stranger had enjoyed it. Those people, it turns out, made extremely accurate predictions [WebMD].
In one experiment, women were asked to partake in “speed dating.” Subjects given reviews by women who had already “dated” participating men were able to gauge how well a date would go better than those who were only shown a picture and profile, and asked to come to their own conclusions.
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To a gambler’s brain, a near miss provides almost the same high as a win, according to a new study that helps explain the allure of slot machines and the difficulty that some gamblers have in walking away. “The near-miss is quite a paradoxical event,” [researcher Luke] Clark says. Gamblers who almost win put “their head down in their hands — they can’t believe it. And then the next thing they do is place another bet” [Science News].
In the small study, published in Neuron [subscription required], researchers had 15 volunteers play a slot machine while their brain activity was recorded with fMRI scans. When the researchers compared the scans, they found that near misses drew more blood to reward regions such as the insula and the ventral striatum than full misses did [ScienceNOW Daily News]. These areas are also activated by rewards like chocolate and cocaine; when the near misses partially activated the so-called reward pathway, it released pleasant doses of the brain chemical dopamine.
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In a new experiment, researchers didn’t have to ask their test subjects whether they’d prefer coffee or tea; instead, they just read their minds. With a nifty bit of technical wizardry, researchers beamed near-infrared light at the volunteers’ foreheads while asking them to mentally decide which of two beverages they liked better. By examining how the light was absorbed by the volunteers’ brain tissue, researchers were able to predict a person’s preference with 80 percent accuracy.
Lead researcher Tom Chau says he hopes a similar device can one day help people with severe cerebral palsy or neuromuscular conditions that keep them paralyzed in unresponsive bodies. “Basically their mind is alert,” he said. “This is kind of the compelling argument behind the work, that these individuals are cognitively capable – they’re aware of their surroundings, they understand what’s going on – but they have no means of communicating their intentions or preferences to the outside world” [Canadian Press].
Coauthor Sheena Luu adds that the device could use simple preferences to build up to larger decisions and thoughts. “If we limit the context – limit the question and available answers, as we have with predicting preference – then mind-reading becomes possible” [The Register], she says.
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The global economic crisis has everybody looking for scapegoats–and now we may have a couple, in the form of a pair of genes that influence people’s desire to take financial risks. The two genes regulate dopamine, the brain chemical associated with reward and risk-taking, and serotonin, the chemical linked to mood and anxiety. In a new study, researchers found that people with the “high-risk” version of the dopamine gene tended to invest in risky but potentially lucrative propositions, while those with the “high anxiety” version of serotonin managed their money more carefully [Reuters].
While an experiment showed a clear correlation between the genes and risk-taking behavior, study coauthor Camelia Kuhnen says the results don’t suggest that all bankers should get their DNA tested. “I wouldn’t want to oversell this as a screening device to find good traders…. Even if I have a gene that predisposes me to taking a lot of financial risk, I could go through a stock market crash that will make me less risk-taking” [Scientific American], says Kuhnen.
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New research shows that even random guesses can sometimes be educated. Published in the latest Nature Neuroscience, a study by neuroscientists Ken Paller and Joel Voss has shown that choices we think of as instinctive may in fact be based on memories that can’t be consciously accessed [Telegraph].
Participants were given a special recognition test in which their memories of kaleidoscopic images were evaluated for accuracy. The subjects were distracted while viewing half of the images and paid full attention to the other half. When they were asked whether they’d seen particular images before, they were also asked if they consciously knew the correct answer or were taking a wild guess.
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When you need to brainstorm ideas for a big project, get yourself to a room that’s painted blue. But when it’s time to proofread the final product, find a red room. Those are the implications of a fascinating new study that measured the effect that colors have on cognition. Researchers found that red can make people’s work more accurate, and blue can make people more creative [The New York Times]. Since people associate red with danger, it primes them to proceed with more caution and diligence, Zhu reasons, while blue’s oceanic connotations put them in a more adventurous mood.
Researcher Juliet Zhu decided to tackle the topic because previous studies had come up with inconsistent findings. Some studies had found that red enhances cognition, for example, while other studies suggest the opposite. Zhu suspected this might be because the work didn’t pay enough attention to which types of cognition were being affected. Red might enhance performance on some tasks, she reasoned, while impairing performance on others [ScienceNOW Daily News].
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Capuchin monkeys not only have the capacity to use tools, they also know which tool is best for the job at hand, according to a new study. Researchers observed capuchin monkeys in the wild testing out different stones and consistently settling on the heaviest, sturdiest stone to crack open palm nuts. Although anecdotal reports existed before, the new study is the first to systematically document tool use in capuchin monkeys. Because capuchins last shared a common ancestor with humans approximately 35 million years ago, the team writes, the capacity for stone-tool use evolved earlier than thought [New Scientist].
Researchers studied eight wild capuchins living in a forested area of Brazil. In several different trials, researchers planted two or three different rocks, of varying hardness, size, and weight, near where the monkeys were feeding. The choices ranged from crumbly sandstone to tough quartzite, with some artificial stones that the monkeys would not normally encounter also thrown in the mix. Capuchins chose the most effective stone for cracking nuts more than 90 percent of the time in four conditions. That figure fell slightly to 85 percent when the monkeys selected from artificial stones of the same size and different weights [Science News].
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