mirrored file at http://SaturnianCosmology.Org/ For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== * COGNITIVE SCIENCE: ON WORD-LEARNING IN DOGS The following points are made by J. Kaminski et al (Science 2004 304:1682): 1) The rate at which most toddlers acquire their vocabulary is astounding: From about 2 years of age, typical English-speaking children incorporate about 10 new words per day into their vocabulary until they reach an average vocabulary size of 60,000 words by the time they graduate from high school (1). Several studies have shown that children have a set of operating principles that guide the task of word learning (2-4). However, it remains a matter of debate which of these principles are unique to language learning and which are more general cognitive abilities that may be shared with other living creatures. 2) The authors investigated the outer limits of a domestic dog's "word learning"; that is, his ability to acquire the relation between a word and the object that this word refers to (the referent). By studying his retrieval behavior with familiar and novel items, the authors specifically tested whether he would be able to infer the referent of a new word by exclusion learning: that is, to "fast map" (5) and retain this knowledge over time. 3) The study animal, Rico, is a border collie and was born in December 1994. He lives as a pet with his owners and was reported by them to know the labels of over 200 items, mostly children's toys and balls, which he correctly retrieved upon request. Rico was first introduced to fetching items when he was 10 months of age, when his owners placed three different items in different locations around the flat and asked the dog for one of these items. Rico was rewarded with food or play if he fetched the correct object. He was gradually familiarized with an increasing number of items. Typically, the owners introduced new items by presenting them and saying their name two or three times. Rico then got the chance to play with the new item, and it was subsequently integrated into the collection of other items. 4) The first experiment was designed to assess Rico's ability to correctly retrieve his various items under controlled conditions. The authors randomly assigned the 200 items he was reportedly familiar with to 20 sets of 10 different items each. While the owner waited with the dog in a separate room, the experimenter arranged a set of items in the experimental room and then joined the owner and the dog. Next, the experimenter instructed the owner to request the dog to bring two randomly chosen items (one after the other) from the adjacent room. While Rico searched for the requested item, he could not see the owner or the experimenter. He retrieved a total of 37 out of 40 items correctly. This first experiment demonstrated that Rico indeed knew the labels of these items. 5) In summary: During speech acquisition, children form quick and rough hypotheses about the meaning of a new word after only a single exposure -- a process dubbed "fast mapping". The authors provide evidence that a border collie, Rico, is able to fast map. Rico knew the labels of over 200 different items. He inferred the names of novel items by exclusion learning and correctly retrieved those items immediately as well as 4 weeks after the initial exposure. The authors suggest that fast mapping thus appears to be mediated by general learning and memory mechanisms also found in other animals and not by a language acquisition device that is special to humans. References (abridged): 1. P. Bloom, How Children Learn the Meanings of Words (MIT Press, Cambridge, MA, 2000) 2. D. A. Baldwin, Dev. Psychol. 29, 832 (1993) 3. C. B. Mervis, J. Bertrand, Child Dev. 65, 1662 (1994) 4. M. Tomasello, Constructing a Language (Harvard Univ. Press, Cambridge, MA, 2003) 5. L. Markson, P. Bloom, Nature 385, 813 (1997) Science http://www.sciencemag.org -------------------------------- Related Material: ANIMAL BEHAVIOR: ON ANTHROPOMORPHISM The following points are made by Clive D. Wynne (Nature 2004 428:606): 1) The complexity of animal behavior naturally prompts us to use terms that are familiar from everyday descriptions of our own actions. Charles Darwin (1809-1882) used mentalistic terms freely when describing, for example, pleasure and disappointment in dogs; the cunning of a cobra; and sympathy in crows. Darwin's careful anthropomorphism, when combined with meticulous description, provided a scientific basis for obvious resemblances between the behavior and psychology of humans and other animals. It raised few objections. 2) The 1890s saw a strong reaction against ascribing conscious thoughts to animals. In the UK, the canon of Conwy Lloyd Morgan (1852-1936) forbade the explanation of animal behavior with "a higher psychical faculty" than demanded by the data. In the US, Edward Thorndike (1874-1949) advocated replacing the use of anecdotes in the study of animal behavior with controlled experiments. He argued that when studied in controlled and reproducible environments, animal behavior revealed simple mechanical laws that made mentalistic explanations unnecessary. 3) This rejection of anthropomorphism was one of the few founding principles of behaviorism that survived the rise of ethological and cognitive approaches to studying animal behavior. But after a century of silence, recent decades have seen a resurgence of anthropomorphism. This movement was led by ethologist Donald Griffin, famous for his discovery of bat sonar. Griffin argued that the complexity of animal behavior implies conscious beliefs and desires, and that an anthropomorphic explanation can be more parsimonious than one built solely on behavioral laws. Griffin postulated, "Insofar as animals have conscious experiences, this is a significant fact about their nature and their lives." Animal communication particularly impressed Griffin as implying animal consciousness. 4) Griffin has inspired several researchers to develop ways of making anthropomorphism into a constructive tool for understanding animal behavior. Gordon Burghardt was keen to distinguish the impulse that prompts children to engage in conversations with the family dog (naive anthropomorphism) from "critical anthropomorphism", which uses the assumption of animal consciousness as a "heuristic method to formulate research agendas that result in publicly verifiable data that move our understanding of behavior forward." Burghardt points to the death-feigning behavior of snakes and possums as examples of complex and apparently deceitful behaviors that can best be understood by assuming that animals have conscious states. 5) But anthropomorphism is not a well-developed scientific system. On the contrary, its hypotheses are generally nothing more than informal folk psychology, and may be of no more use to the scientific psychologist than folk physics to a trained physicist. Although anthropomorphism may on occasion be a source of useful hypotheses about animal behavior, acknowledging this does not concede the general utility of an anthropomorphic approach to animal behavior.(1-4) References: 1. Blumberg, M. S. & Wasserman, E. A. Am. Psychol. 50, 133-144 (1995) 2. De Waal, F. B. M. Phil. Top. 27, 255-280 (1999) 3. Mitchell, R. W. et al. Anthropomorphism, Anecdotes and Animals (State Univ. New York Press, New York, 1997) 4. Wynne, C. D. L. Do Animals Think? (Princeton Univ. Press, Princeton, New Jersey, 2004) Nature http://www.nature.com/nature -------------------------------- Related Material: COGNITIVE SCIENCE: NUMBERS AND COUNTING IN A CHIMPANZEE In this context, let us define "animals" as all living multi-cellular creatures other than humans that are not plants. In recent decades it has become apparent that the cognitive skills of many animals, especially non-human primates, are greater than previously suspected. Part of the problem in research on cognition in animals has been the intrinsic difficulty in communicating with or testing animals, a difficulty that makes the outcome of a cognitive experiment heavily dependent on the ingenuity of the experimental approach. Another problem is that when investigating the non-human primates, the animals whose cognitive skills are closest to that of humans, one cannot do experiments on large populations because such populations either do not exist or are prohibitively expensive to maintain. The result is that in the area of primate cognitive research reported experiments are often "anecdotal", i.e., experiments involving only a few or even a single animal subject. But anecdotal evidence can often be of great significance and have startling implications: a report, even in a single animal, of important abstract abilities, numeric or conceptual, is worthy of attention, if only because it may destroy old myths and point to new directions in methodology. In 1985, T. Matsuzawa reported experiments with a female chimpanzee that had learned to use Arabic numerals to represent numbers of items. This animal (which is still alive and whose name is "Ai") can count from 0 to 9 items, which she demonstrates by touching the appropriate number on a touch-sensitive monitor. Ai can also order the numbers from 0 to 9 in sequence. The following points are made by N. Kawai and T. Matsuzawa (Nature 2000 403:39): 1) The author report an investigation of Ai's memory span by testing her skill in numerical tasks. The authors point out that humans can easily memorize strings of codes such as phone numbers and postal codes if they consist of up to 7 items, but above this number of items, humans find memorization more difficult. This "magic number 7" effect, as it is known in human information processing, represents an apparent limit for the number of items that can be handled simultaneously by the human brain. 2) The authors report that the chimpanzee Ai can remember the correct sequence of any 5 numbers selected from the range 0 to 9. 3) The authors relate that in one testing session, after choosing the first correct number in a sequence (all other numbers still masked), "a fight broke out among a group of chimpanzees outside the room, accompanied by loud screaming. Ai abandoned her task and paid attention to the fight for about 20 seconds, after which she returned to the screen and completed the trial without error." 4) The authors conclude: "Ai's performance shows that chimpanzees can remember the sequence of at least 5 numbers, the same as (or even more than) preschool children. Our study and others demonstrate the rudimentary form of numerical competence in non-human primates." Nature http://www.nature.com/nature -------------------------------- Related Material: ON THE ACQUISITION OF LANGUAGE BY CHILDREN The following points are made by J.R. Saffran et al (Proc. Nat. Acad. Sci. 2001 98:12874): 1) Before infants can begin to map words onto objects in the world, they must determine which sound sequences are words. To do so, infants must uncover at least some of the units that belong to their native language from a largely continuous stream of sounds in which words are seldom surrounded by pauses. Despite the difficulty of this reverse-engineering problem, infants successfully segment words from fluent speech from approximately 7 months of age. 2) How do infants learn the units of their native language so rapidly? One fruitful approach to answering this question has been to present infants with miniature artificial languages that embody specific aspects of natural language structure. Once an infant has been familiarized with a sample of this language, a new sample, or a sample from a different language, is presented to the infant. Subtle measures of surprise (e.g., duration of looking toward the new sounds) are then used to assess whether the infant perceives the new sample as more of the same or something different. In this fashion, we can ask what the infant extracted from the artificial language, which can lead to insights regarding the learning mechanisms underlying the earliest stages of language acquisition. 3) Syllables that are part of the same word tend to follow one another predictably, whereas syllables that span word boundaries do not. In a series of experiments, it has been found that infants can detect and use the statistical properties of syllable co-occurrence to segment novel words. More specifically, infants do not detect merely how frequently syllable pairs occur, but rather the probabilities with which one syllable predicts another. Thus, infants may find word boundaries by detecting syllable pairs with low transitional probabilities. What makes this finding astonishing is that infants as young as 8 months begin to perform these computations with as little as 2 minutes of exposure. By soaking up the statistical regularities of seemingly meaningless acoustic events, infants are able to rapidly structure linguistic input into relevant and ultimately meaningful units. Proc. Nat. Acad. Sci. http://www.pnas.org -------------------------------- Related Material: COGNITIVE SCIENCE: ON LANGUAGE AND HUMAN INTELLIGENCE The following points are made by David Premack (Science 2004 303:318): 1) Humans have acquired six symbol systems: two that evolved --the genetic code and spoken language -- and four that we invented: written language, arabic numerals, music notation, and labanotation (a system for coding choreography). Dobzhansky's quip "All species are unique, but humans are uniquest" raises the question: Is it language, the symbol system that evolved only in humans, that makes humans the "uniquest"? Dobzhansky's quip also raises a more fundamental question: What exactly is the nature of human uniqueness? 2) The grammar or syntax of human language is certainly unique. Like an onion or Russian doll, it is recursive: One instance of an item is embedded in another instance of the same item. Recursion makes it possible for the words in a sentence to be widely separated and yet dependent on one another. "If-then" is a classic example. In the sentence "If Jack does not turn up the thermostat in his house this winter, then Madge and I are not coming over," "if" and "then" are dependent on each other even though they are separated by a variable number of words (1-3). Are animals capable of such recursion? Fitch and Hauser (4) have reported that tamarin monkeys are not capable of recursion. Although the monkeys learned a nonrecursive grammar, they failed to learn a grammar that is recursive. Humans readily learn both. 3) The lack of recursion in tamarins may help to explain why animals did not evolve recursive language, but it leaves open the question of why they did not evolve nonrecursive language. Recursion is not, of course, the only preexisting faculty on which the evolution of language depends. 4) A laboratory chimpanzee does not call to attract the attention of its trainer; instead, it pounds on a resonant surface. Similarly, when chimpanzees become separated in the compound, they do not call to one another, as humans would, but search silently until they see one another and then rush together. If, as the evidence suggests, vocalization in the chimpanzee is largely non-voluntary (reflexive), speech could not have evolved. But then why don't chimpanzees sign to each other? The chimpanzee has voluntary control of its hands. However, sign language depends on the face as well as the hands, and facial expression in the chimpanzee is evidently as reflexive as vocalization. Facial expressions play linguistic roles in signing, such as denoting the boundaries of clauses. A signer processes emotional facial expression in the right hemisphere, but linguistic facial expression in the left hemisphere (5). This does not mean, of course, that chimpanzees could not have evolved a language based on pounding on resonant surfaces, arranging stones on the ground, and so on. But it does suggest that they could not have evolved one that is like either speech or sign. (Of course, speech and sign "travel" with the speaker in a way that stones and resonant surfaces do not.) 5) What are the factors that distinguish human intelligence? A major distinctive feature of human intelligence is flexibility. Animals, by contrast, are specialists. Bees are adept at sending messages through their dances, beavers at building dams, the nuthatch at remembering the location of thousands of caches of acorns it has buried. But each of these species is imprisoned by its adaptation; none can duplicate the achievement of the other. The nuthatch cannot build dams; bees do not have an uncanny memory for hidden caches of food; beavers cannot send messages. Humans, by contrast, could duplicate all these achievements and endlessly more. Why? Is recursive language the key to human flexibility? 6) Human intelligence and evolution are the only flexible processes on Earth capable of producing endless solutions to the problems confronted by living creatures. Did evolution, in producing human intelligence, outstrip itself? Apparently so, for although evolution can do "engineering", changing actual structures and producing new devices, it cannot do science, changing imaginary structures and producing new theories or explanations of the world. Clearly, language and recursion are not the sole contributors to human uniqueness. References (abridged): 1. N. Chomsky, Syntactic Structures (Mouton, The Hague, 1957) 2. S. Pinker, The Language Instinct (Morrow, New York, 1994) 3. M. D. Hauser, N. Chomsky, W. T. Fitch, Science 298, 1569 (2002) 4. W. T. Fitch, M. D. Hauser, Science 303, 377 (2004) 5. E. L. Newport, T. Supulla, in The MIT Encyclopedia of the Cognitive Sciences, R. Wilson, F. Keil, Eds. (MIT Press, Cambridge, MA, 1999), pp. 758-760 Science http://www.sciencemag.org ScienceWeek http://scienceweek.com * Copyright © 2004 ScienceWeek All Rights Reserved US Library of Congress ISSN 1529-1472