November 01, 2007

good-bye, washoe

Three weeks ago, Alex, the world's most famous parrot died. He had a vocabulary of about 100 words and his owner and trainer, psychologist Dr. Irene Patterberg, felt that he could truly communicate with her. Yesterday, another animal known for its astonishing linguistic abilities died: Goodbye, Washoe.

Born in 1966, Washoe was taught American Sign Language (or some sort of signing system) by cognitive scientists R. Allen and Beatrix Gardner. She learned a number of signs (although speakers of ASL didn't all agree that these signs were actually ASL signs) and used them creatively. A big question was whether she had some sort of grammar, which would allow her to combine signs for words to express more complex concepts. At the time, Noam Chomsky's idea that human beings are born with an innate sense of grammar (Universal Grammar) had just become popular. This set in motion a whole range of experiments with great apes. Was there any evidence that they also had language?

the excitement died down in the late 1970s, when Herbert Terrace, a cognitive researcher at Columbia, published a report on a chimpanzee he had been trying to teach language, named Nim Chimpsky. Nim could learn signs, but did so primarily by imitating teachers, Dr. Terrace found by reviewing videos of interactions.

“There was no spontaneity, no real use of grammar,” Dr. Terrace said. He analyzed a video of Washoe, who learned about 130 signs, and said he found evidence that she, too, was reacting to prompts, not engaging in anything like human conversation.

Researchers altered their approach and began teaching with word symbols, called lexigrams, in which symbols stand for words. They also created environments in which animals learned as infants do, first by imitation and later by observation — by watching others communicate, then trying it themselves. Dr. Rumbaugh said a number of chimps and pygmy chimpanzees learned this way and “the evidence screams out that apes have a capacity for a very basic dimension of language.”

While Washoe was explicitly told to use signs, a younger chimpanzee, Loulis, who was raised by her, picked up some signs directly from her. There is no doubt that apes can use signs (arbirary combinations of form and meaning) to convey information, but the question of whether or not they have an understanding of combining signs (i.e. of grammar) to create novel expressions is still very much under debate among linguists.

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