Kanzi: The Ape at the Brink of the Human Mind (34 page)

I first encountered Bev
*
and Connie in 1981, when they were seventeen and nineteen years old, respectively. Both young women had been born with severe brain damage and were profoundly mentally retarded as a result. Despite remedial language programs, neither had learned to speak. Connie, whose motor-speech mechanism was impaired, often vocalized, but for the most part unintelligibly. Bev, who suffered cerebral palsy, was even more vocal, but was also largely unintelligible. Bev and Connie were part of a small experimental program at the Language Research Center in Atlanta, where I work with Kanzi, Sherman and Austin, and the other chimps. Before they began their visits to the center, the two institutionalized young women had been judged to have reached a level of cognitive development equivalent to that of a two-year-old. But to me, and to Mary Ann Romski, who was directing the program, there appeared to be an important difference between the two of them.

The research program was modeled after the center’s Animal Model Project, and therefore involved teaching speech-impaired humans to use lexigrams as referential symbols in a communicative way, just as we had taught chimpanzees to do. As I watched Mary Ann and our joint colleague Rose Sevcik work with these subjects, I became aware of subtle signs that Bev possessed a
degree of comprehension that was absent in Connie. If, for instance, Mary Ann asked Bev, “Do you want a drink?,” Bev’s eyes might flick toward the drinking fountain. Or, if told, “It’s time to go,” Bev’s body might make a slight movement in response. Because of her cerebral palsy, voluntary movement was difficult for Bev, and she could not prevent herself from making involuntary limb and torso movements. Mary Ann and I talked about our separate observations of Bev’s apparent comprehension, and we agreed something different was going on with her compared with Connie. That difference was soon manifested in a different rate of learning lexigrams: Bev learned quickly, while Connie was slow.

I was not directly involved in Mary Ann’s research program, except as an enthusiastic spectator and occasional source of advice on how to proceed when teaching problems arose. To that point in time, my work with Sherman and Austin had served as a model and trouble-shooting device for the human program, particularly in circumventing apparent learning barriers. Every one of the difficulties that Mary Ann faced in installing language in mentally retarded individuals, I had already experienced with Sherman and Austin. In every case, Mary Ann was able to overcome the problem using techniques I had used with the chimps. The rationale of the Language Research Center—to bring together language studies in humans and chimps—was vindicated by these successes. So, too, was it vindicated by my observations of Bev and Connie. Partly from seeing the effect of comprehension on Bev’s symbol acquisition skills, I became aware of the power of comprehension. I also became attuned to the subtle signs that betray comprehension. When, a few years later, Kanzi began to manifest such signs, I was sensitized to detect them. The center’s “childside” and “chimpside” were informing each other in important ways.

The Language Research Center had been established by the Georgia State University Foundation in 1981, and was a direct descendant of an innovative initiative that Duane Rumbaugh
had promoted a decade earlier. He had joined the Yerkes Regional Primate Research Center in 1969, and became associate director and chief of behavior. Yerkes was (and still is) linked with Emory University. It represented the richest resource in the country for the study of primate behavior, including scientific personnel of many different disciplines. In the winter of 1970, the confluence of two factors led to Duane’s initiative. First, he became increasingly fascinated with reports from Allen and Beatrice Gardner of their language project with Washoe, and from David Premack of his project with Sarah. To Duane, the prospect of learning about the components of language acquisition through research with nonhuman primates represented a potential major advance in psycholinguistics. With an ape, it would be possible to manipulate the environment and observe the effects on language acquisition. Such manipulations were not possible with human children. The second factor was a publicly announced agenda by the National Institutes of Health (NIH) to fund research that could be applied directly to social and medical problems facing our society. (The NIH is the major funding agency for biomedical research in the United States.)

“It required just a few seconds’ thought to realize that if we could learn how language develops in a chimpanzee, we would surely have a leg up in learning how to cultivate language in mentally retarded children,” Duane now says, modestly. “I knew that the technology we developed would be vital, both for enabling ease of use by chimps and humans, and for making economical use of manpower.”
¹
Duane wanted a partly automated system, which would therefore be less demanding of instructors’ time and effort than the systems used by the Gardners and Premack. Knowing he had the unique resources of Yerkes to draw upon, he decided to aim for an electronic system that would bring efficiency and objectivity to the project.

Duane recruited the help of his friend and colleague Harold Warner, chief of the Biomedical Engineering Laboratory at Yerkes, and the two of them quickly focused on the idea of a computerized system, probably with a keyboard input. A linguist was needed, and so they asked Ernst von Glaserfield, of the University of Georgia, to join them. Von Glaserfield recommended
that his longtime colleague Pier Pisani, a computer expert, also be part of the team. During the winter of 1970, the four men met many times to create the outlines of a system and assemble a research grant proposal for submission to the National Institutes of Health. “We were confident that ultimately the project would lead to a better understanding of human language and some of its cognitive prerequisites,” Duane, Warner, and von Glaserfield later wrote.
²
A four-year grant was awarded in the spring of 1971, and the LANA Project was born.

LANA stood for LANguage Analogue, which relates in part to the symbol system devised for the project. Lana was also the name of the first chimpanzee to work with the system. Von Glaserfield was principally responsible for developing the syntax that formed Lana’s symbol strings, which he called Yerkish, in honor of Robert Yerkes, who had founded the Primate Research Center in 1924. Each symbol, or lexigram, was arbitrary and stood for a single word, including verbs, nouns, and adjectives. Each lexigram was built from combinations of one, two, three, or four geometric forms, of which there were nine in all; there was a total of several hundred potential Yerkish words. Different classes of words were denoted by the use of one of three different primary colors.

A subset of the lexigrams was displayed on a five-by-five matrix keyboard. When a key was pressed and released, the lexigram
went from being dimly lit to brightly illuminated. In addition, the lexigram was displayed on a projector above the keyboard, and a sequence of keystrokes produced a sequence of lexigrams—a “sentence”—on the projector, such as “Please Machine Give Juice.” Being computerized, the system could operate day and night and did not require the presence of an instructor. Lana could interact with the machine and control aspects of her environment at will. In addition, all use of the keyboard, by chimp and instructors, was stored in the computer, bringing a measure of objectivity to the recording of communicative interactions.

Lana gradually acquired a large productive vocabulary and learned to generate a series of stock sentences, by which she typically gained food, turned music on, or obtained some other object she wanted. In addition to the stock sentences, Lana occasionally generated novel sentences, such as asking for an overripe banana by saying,
You give banana which is black
. But these were the minority of her utterances. Although Lana’s behavior was impressively languagelike, we eventually realized that her abilities were limited in important ways, as I described earlier. The focus on engendering productive behavior meant that Lana’s comprehension was not well developed. As I described earlier, only when our work with Sherman and Austin was well advanced did we come to appreciate fully this key distinction. Nevertheless, Lana’s success with the computerized keyboard system was sufficient to encourage Duane to embark on the second aspect of the project: to discover whether nonspeech communication could be taught to severely mentally retarded children who are unable to speak.

There are at least 1.25 million children in the United States who are either without speech, or whose speech is severely impaired, as a result of neurological, physical, or psychological disability. For a long time, clinicians favored persisting with speech therapy with such children, fearing that the teaching of nonspeech communication might inhibit whatever latent capacity for spoken language
still existed. As a result, the development of nonspeech communication systems—namely, signs of some kind—has only recendy become fully established. For instance, when the first volume of
Language Perspectives
, which is now a leading journal in the field, was published in 1974, its inclusion of a section on such systems was considered a major advance on earlier publications concerning language acquisition and intervention.

Nonspeech communication systems, or augmentative language systems, can be divided into two types: aided and unaided. The terms refer to whether or not some piece of equipment is required for communication. Gestures, mime, and manual sign languages, for instance, are unaided systems, whereas anything that uses physical symbols, such as pictographs or arbitrary lexigrams, are aided systems. The LANA system is an aided system. An important advantage that aided systems offer, particularly those like the LANA system that use visual-graphic symbols, is that the signal does not fade. In spoken language, words as symbols have to be brought to mind, and then produced. And once produced, they reside only in the listener’s memory. Manual gestures rely on recall of the symbol by the producer, and are similarly transitory. A visual-graphic symbol, on the other hand, is available for recognition, not recall, by the producer, and once indicated for use may remain visible for as long as is required. Visual-graphic systems therefore place fewer cognitive demands on mentally retarded individuals, thus giving them an advantage among nonspeech systems.

The key issue facing those who wish to teach symbolic communication to speech-impaired children is the absence of a clear understanding of the nature of language acquisition and how it relates to other cognitive development. The different domains of cognitive development are by no means independent, and must interact synergistically. As Elizabeth Bates and her colleagues have shown, the best predictor of a child’s skill on nonverbal tasks is the level of language comprehension obtained by the child. The mentally retarded child is therefore doubly disabled, often failing to acquire language, which would promote further mental development.

Since nonimpaired children acquire language spontaneously and with ease and speed, they offer no real clue as to how impaired children might learn. The very reasonable assumption was therefore made that children with extreme learning difficulties would have to be taught a communicative system in a very structured way, rather than be encouraged to learn as other children do.