- Gamers Better at Fast Decision-Making
- Oversexed Female Snails Make Males Chase Each Other
- Close Encounters With Asteroids Happen Often
- The More Victims, the Less Severe the Judgment
- Robots Taught How to Deceive
Posted: 13 Sep 2010 12:12 PM PDT
Don't tell that guy blasting rampaging zombies to smithereens in his favorite videogame that he's getting lessons in efficient decision making.
Wait until he's done to deliver this buzz kill: Playing shoot-'em-up, action-packed videogames strengthens a person's ability to translate sensory information quickly into accurate decisions. This effect applies to both sexes, say psychologist Daphne Bavelier of the University of Rochester in New York and her colleagues, even if females generally shun videogames with titles such as Dead Rising and Counter-Strike.
Action-game players get tutored in detecting a range of visual and acoustic evidence that supports increasingly speedy decisions with no loss of precision, the scientists report in the Sept. 14 Current Biology. Researchers call this skill probabilistic inference.
"What's surprising in our study is that action games improved probabilistic inference not just for the act of gaming, but for unrelated and rather dull tasks," Bavelier says.
Unlike slower-paced videogames that feature problems with specific solutions, action videogames throw a rapid-fire series of unpredictable threats and challenges at players. Those who get a lot of practice, say, killing zombies attacking from haphazard directions in a shifting, postapocalyptic landscape pump up their probabilistic inference powers, Bavelier proposes.
Psychologist Alan Castel of the University of California, Los Angeles, calls the new study "thorough and intriguing." Much remains to be learned, though, about whether and to what extent video-induced thinking improvements aid other skills, such as pilots' ability to land airplanes in challenging conditions.
Bavelier's group tested 11 men who reported having played action videogames at least five times a week for the past year and 12 men who reported no action videogame activity in the past year. Participants in each group averaged 19 to 20 years of age.
Men in both groups looked at dot arrays on a computer screen and had up to 2 seconds to indicate with an appropriate keystroke the main direction in which each set of dots was moving. Arrays ranged in difficulty, with some having almost all dots moving in the same direction and others having slightly more than half the dots moving in the same direction.
Action gamers responded substantially faster than nongamers to dot arrays at all difficulty levels, especially tough ones, while detecting dots' motion direction as accurately as peers did.
Game players showed a similar speed advantage on an auditory task. Volunteers heard background noises through headphones and had to decide whether oscillating sounds of varying frequencies were heard on the right or the left.
Some gamers may have superior probabilistic inference skills to begin with, but an additional experiment indicates that playing action games amplifies an ability to analyze sensory information, Bavelier says.
Her team randomly assigned seven men and seven women to play two action videogames for a total of 50 hours, with no more than two hours of play per day. Another four men and seven women followed the same rules but played a videogame that involves directing the lives of simulated characters to achieve certain goals.
None of the participants, who averaged 26 years of age, reported having played videogames of any type in the previous year.
Both groups showed marked improvement in game-playing skills after completing the assignment. But action gamers responded markedly faster to dot and noise tasks than did the group that played the simulation game, with comparable accuracy.
Posted: 13 Sep 2010 10:57 AM PDT
Fed up with attention they don't need, some female snails have learned to smell like guys.
Unlike other species of periwinkle snail, Littorina saxatilis ladies can't be identified from chemical cues in their slime trail.
Deprived of their standard mate-finding trick, male L. saxatilis chase trails indiscriminately, learning only at the last moment whether they've lucked out.
This confused singles scene has likely been fueled by evolutionary pressures that "select for mechanisms in the female to avoid both male harassment and excessive matings," wrote researchers led by Kerstin Johannesson, a marine ecologist at Sweden's University of Gothenburg, in a paper published in Public Library of Science ONE.
Johannesson's group had noticed that male Littorina littorea snails, a closely-related periwinkle species that shares L. saxatilis' coastal Swedish habitat, usually follow the mucous trails of females, while L. saxatilis males demonstrate no such preference.
Because male and female periwinkles look similar from the outside, the trail-following mixup means that "observed frequencies of male-male pairings in the wild [are] exceptionally high in this species," wrote the researchers.
Two explanations made sense to Johanneson's team. Either the females were disguising themselves, or male L. saxatilis were just aromatically clueless.
To investigate these propositions, the researchers studied trail-tracking behaviors in two more periwinkle species, L. obtusata and L. fabalis.
Once again, males followed females, underscoring the ubiquity of sex-specific trails in periwinkles. And when L. saxatilis males found trails left by other periwinkles, they generally followed the females. Their sense of smell seems to work just fine. Instead, it seems that a sex-specific "mucous cue is absent in female L. saxatilis," wrote the researchers. "They have either permanently lost this cue or have the ability to optionally remove the cue."
The females' hiding is likely due to the burdens of reproduction.
During mating, when the weight of two snails is supported by just one, and waves drag on double the usual surface area, it's much easier for snails to fall into the sea.
This risk is further magnified by the extraordinary population densities of L. saxatilis, which are more than 100 times greater than in the other periwinkles.
As a result, "expected male-female encounter rates would be two orders of magnitude greater in this species," wrote Johanneson's team. For every unwanted encounter experienced by the average periwinkle, an L. saxatilis will have one thousand.
This is, of course, as much a problem for males as for females. But whereas females improve the chances of passing on their genes by lavishing care on their finite supply of eggs, males enhance their legacy by mating as often as possible.
"Adding to the number of lifetime matings is their only way to increase lifetime fitness," wrote the researchers. "Hence males would be prepared to take larger risk compared to females and strive to mate as frequently as possible despite these costs."
In response, the females go into hiding.
Image: 1) Littorina saxatilis./Björn Canbäck, University of Gothenburg. 2) Copulating L. saxatilis./Patrik Larsson.
Citation: "Indiscriminate Males: Mating Behaviour of a Marine Snail Compromised by a Sexual Conflict?" By Kerstin Johannesson, Sara H. Saltin, Iris Duranovic, Jon N. Havenhand, Per R. Jonsson. Public Library of Science One, August 9, 2010.
Posted: 13 Sep 2010 10:49 AM PDT
The only thing that was particularly unusual about two asteroids that zipped past Earth September 8, astronomers say, was that anybody noticed them.
Such close approaches — one of the asteroids passed within 79,000 kilometers of Earth — actually happen several times a week, according to scientists' calculations. Yet some media outlets described the close encounter as if it were a brush with Armageddon.
"Quite frankly, I don't know why they're making such a fuss about it," says astronomer Brian Marsden of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "This is essentially nothing."
Astronomers first spotted the two asteroids three days before their close encounter with Earth, using the Catalina Sky telescope near Tucson, Ariz., which routinely scans the skies for near-Earth objects. At the time they estimated the larger asteroid to be 10 to 20 meters in diameter, and the smaller 6 to 14 meters across. But subsequent observations by Richard Binzel and Francesca DeMeo of MIT using NASA's Infrared Telescope Facility on Hawaii's Mauna Kea showed that the objects were actually only about half that size.
The discovery of the two space rocks demonstrates that programs like the Catalina survey, designed to find much larger near-Earth asteroids that do have the potential to cause devastating collisions, can also find smaller bodies, Marsden notes.
It might be a little unusual to have two asteroids swing by hours apart. But with small asteroids passing by Earth several times a week, there's always a chance that two could pass by in the same day, he adds.
Much more intriguing to astronomers was the discovery of a small near-Earth asteroid by the Catalina survey in 2008 just hours before it landed in Sudan, where researchers later recovered the fragments.
"The small fry are interesting, not because of damage," Binzel says, "but because of their potential for delivering 'free samples' to Earth."
Posted: 13 Sep 2010 10:14 AM PDT
An examination of jury verdicts over the past decade involving people charged for exposing others to toxic substances, has revealed that the more victims are involved in a case, the less harshly the perpetrator of the crime is penalized.
The study, which also included two experiments in the lab, is the first to show that the bias toward feeling empathy for a single individual versus many — known as the identifiable victim bias — causes people to make judgments based on emotion that are disproportionate to the severity of a crime.
"The inspiration for the study was the observation that we tend to focus an extraordinary amount of attention and resources to crimes that have a really small number of victims, and have a harder time remaining engaged to larger scale kinds of crime," said psychologist Loran Nordgren of Northwestern University, lead author of the paper Aug. 25 in Social Psychological and Personality Science (.pdf).
The bias, which the researchers named the scope-severity paradox, has implications for a wide variety of fields, including the politics and media coverage of large-scale issues such as climate change or mass genocide.
"It fits well with a line of research that shows that as the number of people who are victims of some problem — whether it's a crime or a famine — the responsiveness to it, and the likelihood of taking action to reduce the problem, decreases," said psychologist Paul Slovic of the University of Oregon, who was not involved in the study.
It has to do with the way empathy works, Slovic said. People empathize with people by putting themselves in the other person's shoes. The more shoes there are, the harder it is to empathize with any single individual. People don't multiply their feelings of empathy by the number of people involved.
The study tested whether the identifiable victim bias applies to the severity of punishment given in a series of three experiments. In the first experiment, participants were asked to read a story about a financial adviser who defrauded his clients. Half the participants read a story where only two or three people were harmed, and the other half read a story where dozens of people were harmed.
When asked to evaluate the severity of the crime and recommend a punishment, the fictional financial adviser who defrauded just a few people was judged more harshly than the one who defrauded many.
In the second experiment, participants were asked to read a story about a food processing company that sold tainted food and made people sick. The first group were given a basic description of the victims, and the second group received a photo of one of the victims along with her name and occupation. Participants given the photo judged the food processing company more harshly.
"When we made one individual identifiable, what that did was that it only partially corrected the effect," Nordgren said. "There was no case where we were able to get people to punish more for harming more."
The researchers also examined 133 jury cases between 2000 and 2009 involving exposure to toxic chemicals. They found as the number of people that were effected by the toxic chemicals increased, the amount of total damages the person responsible was asked to pay decreased.
"The study is an exceptionally elegant package because it has a demonstration of the phenomenon in the lab, in the field, and gives you a remedy," said economist George Loewenstein of Carnegie Mellon University, who did the original studies on the identifiable victim effect.
"The sky level picture is that even though our emotions provide the impetus for empathetic behavior, they provide a very poor guide to when we should be generous and how generous we should be, or when we should be punitive and how punitive we should be," Loewenstein said.
There are a some exceptions to the study, Nordgren said. If a case is extraordinarily different than cases that have come before or on a different scale, it doesn't follow the same rules.
For his next project, Nordgren is interested in looking at how identifiability of the perpetrators affects their punishment. He guesses that if the perpetrator of the crime is less identifiable, like an unbranded company versus a well known one, people will be less likely to care about the crimes committed.
Image: Flickr/Rainforest Action Network.
Posted: 13 Sep 2010 08:30 AM PDT
By Duncan Geere, Wired UK
Researchers at the Georgia Institute of Technology may have made a terrible, terrible mistake: They've taught robots how to deceive.
It probably seemed like a good idea at the time. Military robots capable of deception could trick battlefield foes who aren't expecting their adversaries to be as smart as a real soldier might be, for instance. But when machines rise up against humans and the robot apocalypse arrives, we're all going to be wishing that Ronald Arkin and Alan Wagner had kept their ideas to themselves.
The pair detailed how they managed it in a paper published in the International Journal of Social Robotics. Two robots — one black and one red — were taught to play hide and seek. The black, hider, robot chose from three different hiding places, and the red, seeker, robot had to find him using clues left by knocked-over colored markers positioned along the paths to the hiding places.
However, unbeknownst to the poor red seeker, the black robot had a trick up its sleeve. Once it had passed the colored markers, it shifted direction and hid in an entirely different location, leaving behind it a false trail that managed to fool the red robot in 75 percent of the 20 trials that the researchers ran. The five failed trails resulted from the black robots' difficulty in knocking over the correct markers.
"The experimental results weren't perfect, but they demonstrated the learning and use of deception signals by real robots in a noisy environment," Wagner says. "The results were also a preliminary indication that the techniques and algorithms described in the paper could be used to successfully produce deceptive behavior in a robot."
When asked about whether this was really a good idea, bearing in mind the events of Terminator 2, Arkin added: "We have been concerned from the very beginning with the ethical implications related to the creation of robots capable of deception and we understand that there are beneficial and deleterious aspects. We strongly encourage discussion about the appropriateness of deceptive robots to determine what, if any, regulations or guidelines should constrain the development of these systems."
Image: Flickr/Gavin Tapp
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