Retrospectacle: A Neuroscience Blog

i-545a93736124bb0ec99225ab7e3d7fac-strawberry.bmp Dr. Irene Pepperberg has recently published an interesting paper in Language Sciences, regarding the ability of grey parrots to learn new words for unfamiliar objects using phonemes they already know. But, intuitively, the ability to create new words out of known phonemes would require that a parrot grasp that object labels are composed of individual parts which can be interchanged and applied to new objects. Do parrots really have that ability?

The answer may hinge on whether parrots engage in mimicry (mindlessly “parroting” back noise) or imitation (intentional copying of a novel act to achieve similar results).

(Continued under the fold…………)


As Pepperberg says:

Imitation can also be seen as the integration of a number of familiar actions in novel ways to produce that novel act of particular interest is what happens when the targeted novel vocalization can be constructed from related elements already in the parrot’s repertoire. This particular type of combinatory behavior is actually a form of vocal segmentation. Successful segmentation shows that the bird understands that his existent labels are comprised of individual units that can be recombined in novel ways to create novel vocalizations. Previous data suggested, but could not substantiate, this behavior; current data do just that. Moreover, such evidence implies that a parrot has phonological awareness or at least control of linguistic processing and analysis of linguistic knowledge. The results have implications for other fields, notably the evolution of language.

To get at this question, Pepperberg observed two of her longtime test subjects: the grey parrots Alex (27) and Arthur (aka “Wart,” 4). Alex had been previously trained to identify, request, refuse, categorize, and quantify over 100 objects using English word and phrases. Arthur, on the other hand, was much younger and more ‘verbally naive’ with only 4 referential labels learned at this time point. Pepperberg’s lab utilizes the model-rival technique, where a trainer interacts with another human (usually a student) in front of the parrot. While the bird watches, the two humans handle a new object, and the trainer questions the student about the object to give it a name (ie “What’s here?” or “What toy?”).

This technique was used to train both parrots on the label “spool,” and after learning the label, were taped with a microphone and converted to a sonogram. Interestingly, there seemed to be a significant difference between the formation of the word “spool” between Alex (the experienced parrot) and Arthur (the novice). Alex, during his training and while watching Arthur’s training, began using combinations of existing phonemes (ones he already knew) to try to label the new object (the wooden spool). Alex was trying to mash “s” onto a word he already knew—”wool.” The resulting label was more like “swool” than “spool,” and he kept this tag for almost a year until he began reproducing the word perfectly. (Recorded sonograms below.)

i-4ad58a71e9001de676b2253980097d37-pepperberg fig 1.bmp

Alex’s vocal patterns closely resembled Dr. Pepperbergs: however there was just one problem. Irene didn’t train Alex on “spool” but she *did* train him on the word “wool” over 20 years earlier. The sonograms suggested that Alex modified a pre-existing word in his vocabulary–even preserving the vocal idiosyncrasies of the initial person who taught him the base word.

Pepperberg, I.M. 2007. “Grey parrots do not always ‘parrot’: the roles of imitation and phonological awareness in the creation of new labels from existing vocalizations.” Language Sciences. 29. 1-13.

Comments

  1. #1 daniele
    February 9, 2007

    maybe mirror neurons could be an issue in this case

  2. #2 AgnosticOracle
    February 9, 2007

    I’d never really thought about how parrots develop new words from sounds and syllables.

    Have you read Jared Diamond’s The Third Chimpanzee? He has a section in there where he talks about the development of pidgins and creoles from speakers who speak different languages. (I suspect the research came from elsewhere, but his book is where I read about it.).

    One of the things is how pidgins will be made of the intersection of the sounds in the two languages. It is interesting to see the extent to non-verbally naive parrots rely or prefer the sounds they already know to new ones.

    PS. That is an especially cute picture of your parrot with a strawberry.

  3. #3 Wesley R. Elsberry
    February 9, 2007

    I’m glad to hear that Dr. Pepperberg is still getting publications out with Alex and Arthur. Has she found a good base of operations? I know that after leaving U. of Arizona she was left academically stranded by budget-cutting at MIT. That was a while back, though.

    Did this paper also discuss Alex’s “naper” and “pail” vocalizations?

  4. #4 Shelley
    February 10, 2007

    Wesley: Yes, good to see she’s still getting published despite funding woes. She’s at Brandeis right now, under less that ideal conditions, but still getting her research done and getting funding from her private foundation. I did an interview with her a couple months ago where she talks a bit about it (search for Pepperberg interview, should do it). The paper didn’t discuss naper/pull: what that?

    Agnostic: No, haven’t read that book, would you recommend it? And Pepper says thanks! :)

  5. #5 AgnosticOracle
    February 12, 2007

    I definitely recommend Jared Diamond’s The Third Chimpanzee. It could be described as the prequel to Guns, Germs, and Steal. The books looks at the various behaviors often consider uniquely human and what similar or precursor behaviors can also be found in other animals.

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