Friday Grey Matters: Grey Parrots Don't Always "Parrot"

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.)

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.