Friday, April 28, 2017

Y is for Yerkish - Chatting with Chimps Leads to Speech Assistance Technology for Those with Autism

The ability to speak has been viewed as the most important factor that distinguishes humans from other animals.  Many modern linguists, most famously Noam Chomsky, have argued that language is, indeed, a unique characteristics of humans.  This is not to say that other animals don’t communicate – dolphins use whistles to identify themselves and send information to one another while elephants use trumpeting to call to each other to signal danger as well as a complicated form of sign language to communicate intentions, moods and desires.  Yet no naturally occurring language that exists in other animals has the complexities, flexibility and developmental capacity of human language. 

During the early 1900’s, several scientists attempted to teach human language to chimpanzees but were   unsuccessful.  It later came to light that this was not due to the potential of the chimps but to structural differences in ape and human vocal tracts.  This meant the chimps weren’t able to physically produce the sounds of human language.  Later research focused on teaching a non-vocal language to primates. In the late 1960’s Washoe, a female chimpanzee learned to use well over 350 signs, learning many spontaneously from observing the humans around her.  Around the same time, others used tokens that stood for words, teaching the ape’s to arrange them in different orders.  A female chimp named Sarah learned to produce streams of tokens which obeyed a grammar and could use if-then-else expressions. 

Watch this video, A Conversation With Koko The Gorilla, an award-winning documentary about an amazing gorilla who learned to converse with a researcher using sign language.

Then in the 1970’s, Ernst von Glasersfeld developed a language that researchers first taught to the female chimp named Lana.  It was called “Yerkish” after Robert M. Yerkes, the founder of the laboratory within which the language project was carried out. Lana was taught to comprehend and use symbols via an innovative computer-based keyboard.

Yerkish, not to be confused with Yiddish, has developed into a language used to communicate with nonhuman primates. The language was initially used to communicate with the primates at the Yerkes National Primate Research Center in Atlanta, GA. In addition to Lana, Duane Rumbaugh used the language to communicate with two other chimpanzees at Yerkes. The symbols represent but are not necessarily exact portrayals of words.  A keyboard with a lexigram laid out on the keys is used by the primates and the researchers. Lexigram boards were composed of three panels with a total of 384 keys. When pressed, keys would light up and the associated symbol would be projected on a screen above the keyboard.  “Correct” or “legal” sentence resulted in automatic results.  For example, the sentence “Please Machine Give Juice” would lead to juice being dispensed.  Other sentences or questions would be responded to by human caregivers also using the keyboard.

As this project continued it became clear that keyboard facilitated learning successfully helped chimps develop language skills.  These skills went beyond just learning the exact associations that were taught to them.  The chimps were able to spontaneously generate novel combinations of symbols to communicate desires and ask questions along with answering questions and completing assigned tasks from researchers. 

There are those who say that there is no reason to waste time and money trying to teach human language to apes.  Yet the language project with apes provided the foundation for creating communication boards and keyboard facilitated language development devices for use with non-verbal children with autism. This further led to developments in speech assistive technology that has proven to be invaluable for those with autism who have trouble learning vocabulary and grammar, don’t understand the social rules for conversations, or have difficulties spontaneously using spoken language.

View this segment of a video produced for Autism Acceptance Month of a young man named Dillan who uses technology to convey what the world is like for him.  His words remind us how important it is to ensure everyone with a voice can be heard.

No comments:

Post a Comment