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| Author | Topic: Mind and Consciousness |
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Language may shape human thought (Moderator) |
posted 12/14/04 1:53 PM
Language may shape human thought 19:00 19 August 04 NewScientist.com news service Language may shape human thought – suggests a counting study in a Brazilian tribe whose language does not define numbers above two. Hunter-gatherers from the Pirahă tribe, whose language only contains words for the numbers one and two, were unable to reliably tell the difference between four objects placed in a row and five in the same configuration, revealed the study. Experts agree that the startling result provides the strongest support yet for the controversial hypothesis that the language available to humans defines our thoughts. So-called “linguistic determinism” was first proposed in 1950 but has been hotly debated ever since. “It is a very surprising and very important result,” says Lisa Feigenson, a developmental psychologist at Johns Hopkins University in Baltimore, Maryland, US, who has tested babies’ abilities to distinguish between different numerical quantities. “Whether language actually allows you to have new thoughts is a very controversial issue.” Peter Gordon, the psychologist at Columbia University in New York City who carried out the experiment, does not claim that his finding holds for all kinds of thought. “There are certainly things that we can think about that we cannot talk about. But for numbers I have shown that a limitation in language affects cognition,” he says. “One, two, many” The language, Pirahă, is known as a “one, two, many” language because it only contains words for “one” and “two”—for all other numbers, a single word for “many” is used. “There are not really occasions in their daily lives where the Pirahă need to count,” explains Gordon. In order to test if this prevented members of the tribe from perceiving higher numbers, Gordon set seven Pirahă a variety of tasks. In the simplest, he sat opposite an individual and laid out a random number of familiar objects, including batteries, sticks and nuts, in a row. The Pirahă were supposed to respond by laying out the same number of objects from their own pile. For one, two and three objects, members of the tribe consistently matched Gordon’s pile correctly. But for four and five and up to ten, they could only match it approximately, deviating more from the correct number as the row got longer. The Pirahă also failed to remember whether a box they had been shown seconds ago had four or five fish drawn on the top. When Gordon’s colleagues tapped on the floor three times, the Pirahă were able to imitate this precisely, but failed to mimic strings of four of five taps. Babies and animals Gordon says this is the first convincing evidence that a language lacking words for certain concepts could actually prevent speakers of the language from understanding those concepts. Previous experiments show that while babies and intelligent animals, such as rats, pigeons and monkeys, are capable of precisely counting small quantities, they can only approximately distinguish between clusters consisting of larger numbers. However, in these studies it was unclear whether an inability to articulate numbers was the reason for this. The Pirahă results provide a much stronger case for linguistic determinism, says Gordon, because, aside from their language, they are otherwise similar to other adult humans, whereas there are many more factors that separate babies and animals from adult humans. However, scientists are far from a consensus. Feigenson points out that there could be other reasons, aside from pure language, why the Pirahă could not distinguish accurately for higher numbers including not being used to dealing with large numbers or set such tasks. “The question remains highly controversial,” says psychologist Randy Gallistel of Rutgers University in Piscataway, New Jersey. “But this work will spark a great deal of discussion.” Journal reference: Science Express (19 August 2004/ Page 1/ 10.1126/science.1094492) Celeste Biever http://www.newscientist.com/news/news.jsp?id=ns99996303 |
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Lab chimp speaks his own language (Moderator) |
posted 12/14/04 1:59 PM
Lab chimp speaks his own language 10:15 02 January 03 A bonobo has surprised his trainers by appearing to make up his own "words". It is the first report of an ape making sounds that seem to hold their meaning across different situations, and the latest challenge to the orthodox view that animals do not have language. Kanzi is an adult bonobo kept at Georgia State University in Atlanta. He has grown up in captivity among humans, and is adept at communicating with symbols. He also understands some spoken English, and can respond to phrases such as "go out of the cage" and "do you want a banana?" Jared Taglialatela, Sue Savage-Rumbaugh and Lauren Baker, who work with Kanzi, noticed that he was making gentle noises during his interactions with them. "We wanted to know if there was any rhyme or reason to when they were produced," says Taglialatela. So his team studied 100 hours of videotape showing Kanzi's day-to-day interactions and analysed the sounds he made at various times. They picked situations in which the bonobo's actions were unambiguous: for example, while he was eating a banana, pointing to the symbol for "grapes", or responding to a request to go outside by leaving the cage. They identified four sounds that Kanzi made in different contexts - banana, grapes, juice and yes. In each of these contexts, Kanzi made the same sound. "We haven't taught him this," says Taglialatela. "He's doing it on his own." Emotional state Some will argue that the sounds are simply the result of differences in Kanzi's emotional state. Taglialatela concedes that emotions may play a part, but says they are not the whole story. For instance, Kanzi's sound for "yes" stayed the same across very different emotional states. Primatologist Frans de Waal of Emory University in Atlanta, Georgia, agrees. "That emotion is involved doesn't rule out at all that he's following rules that have some sort of cognitive component," he says. Kanzi is just the latest primate to challenge the view that animals have no language ability. Language used to be popularly defined as symbolic communication until Washoe, a chimpanzee, stumped everyone by learning to communicate in American Sign Language. "The linguists then came up with a definition that emphasised syntax much more than symbols," says de Waal. "Sometimes we feel it's a bit unfair that they move the goal posts as soon as we get near." High, medium or low Recently researchers studying Campbell's and Diana monkeys in the Ivory Coast in West Africa found some evidence of syntax in the calls the monkeys made. And Karen Hallberg and Sally Boysen of Ohio State University in Columbus have noticed hints that when chimps see food, they make calls that specify its desirability as high, medium or low, and that other chimps can interpret the sounds. But Kanzi comes closest yet to providing concrete evidence that apes can make sounds that carry a particular meaning. "Kanzi is modifying his sounds to denote certain things in his environment," says de Waal. "That's very special." The results are significant and exciting, agrees primatologist John Mitani of the University of Michigan in Ann Arbor. "Despite the fact that we have had glimmerings of this in the monkey world, few instances of anything like this have been documented among our closest living relatives, chimps and bonobos," he says. Flexible and applicable Taglialatela's team has now started studying seven more bonobos in their lab, some of which have not been language-trained. They are also analysing Kanzi's sounds to see if he is actually trying to imitate human speech. Until more results are in, Mitani and de Waal caution against drawing any firm conclusions. For Kanzi's ability to be considered similar to language, it must be flexible and applicable to many different situations, they say. And Hallberg says she will not consider Kanzi's sounds to be communication until other bonobos are shown to respond to them appropriately. Nevertheless, the observations add to the growing body of evidence that language skills did not just show up suddenly in humans, and hint that non-human primates may have abilities that could be described as primitive language. "There have to be evolutionary precursors to what we do," says Mitani. "We are beginning to find them in the primate world." Journal reference: International Journal of Primatology (vol 24, p 1) Anil Ananthaswamy http://www.newscientist.com/news/news.jsp?id=ns99993218 |
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The Brain Sees What We Don't Robert Roy Britt (Moderator) |
posted 11/3/05 12:36 AM
The Brain Sees What We Don't Robert Roy Britt LiveScience Managing Editor LiveScience.com Wed Nov 2, 2:00 PM ET Your brain sees and does more than you know, according to a new study that points to the mysterious workings of the unconscious mind. ADVERTISEMENT To come to this heady conclusion, scientists had to zap the brains of healthy volunteers (and rather brave ones, we might add) and temporarily shut down the part of the brain that processes visual information. For a fraction of a second, a pulse of energy called transcranial magnetic stimulation shut down each person's visual cortex. That's the part of the brain known to process what we see. The volunteers stared at a computer screen during this moment of blindness while a simple image flashed for an instant. See that? The scientists then asked the study subjects if they had seen a horizontal or vertical line in one test, and a red or green dot in the other. All nine of them said they'd seen nothing each time. When asked to guess what they'd seen, however, they did significantly better than 50-50. Those who'd been blind witness to a line guessed its orientation accurately 75 percent of the time. Those who'd been shown a dot guessed its color right in 81 percent of the cases. "Even though the human primary visual cortex activity was temporarily shut down, it's clear that detailed visual information was still being processed unconsciously," said Tony Ro, a psychologist at Rice University and leader of the study. Experts had thought all color information was processed in a certain region of the brain's thalamus, governor of all incoming sensory information. But there must be multiple pathways in the brain through which visual information flows, the results indicate. The unconscious mind The new study is detailed this week in the online edition of the Proceedings of the National Academy of Sciences. It contributes to a growing pile of evidence that has yet to reveal what consciousness is. Ro said his team's findings provide evidence for a longstanding and controversial speculation made by Sigmund Freud and others that the brain churns some information without us being aware. Freud called it "unconscious processing." Previous studies in patients with brain damage reached similar conclusions: Patients who said they couldn't see an object could, when pressed, identify its shape and location. Researchers call the phenomenon blindsight, and some say it indicates the brain has an unconscious mode that might be at the root of transcendental experiences for which the conscious mind can't account. http://news.yahoo.com/s/space/20051102/sc_space/thebrainseeswhatwedont |
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