Edward Klima, an eminent linguist who was one of the first scholars to pay serious attention to sign languages, and in so doing helped them win long-denied recognition as languages in their own right, died Sept. 25 in the La Jolla section of San Diego. He was 77 and had lived in La Jolla for many years.

The cause was complications of brain surgery, his family said.

At his death, Klima was emeritus professor of linguistics at the University of California, San Diego. He was also an adjunct professor at the Salk Institute for Biological Studies in San Diego and the associate director of the institute’s laboratory for cognitive neuroscience.

Much of Klima’s work was done in collaboration with his wife, Ursula Bellugi, a professor at Salk and the laboratory’s longtime director. They were known in particular for their long, painstaking unraveling of the grammatical structure of American Sign Language, and for using what they found to illuminate the workings of all language, signed and spoken, in the brain.

Klima and Bellugi received the American Psychological Association’s Award for Distinguished Contributions in 1992.

Before the couple began their research in 1970, everything known about the human language instinct came from the study of spoken languages. Their book “The Signs of Language” (Harvard University, 1979) was a landmark. Written with 10 associates, it is the first comprehensive study of the grammar and psychology of signed languages.

Recent work

More recently, Klima collaborated with his wife on extensive studies of Williams syndrome, a rare genetic disorder that combines mental retardation with heightened language ability.

When Klima and Bellugi began work on American Sign Language, few people considered sign languages to be real languages. ASL, used by a quarter-million to a half-million deaf people in the United States and Canada, was widely disparaged as either a rude pantomime, devoid of grammar, or a broken version of English, rerouted to the hands. Deaf people were made to feel ashamed of it. Teachers of the deaf tried to suppress it, forcing pupils to speak and read lips instead, no mean feat if one cannot hear.

Working with deaf informants, Klima and Bellugi established conclusively that the world’s signed languages — and there are more than a hundred of them — are very much real languages, as complex, abstract and systematic as spoken ones. In ASL, they found a lexicon bursting with nouns, verbs, adjectives, adverbs and pronouns; orderly grammar and syntax quite different from those of English; indigenous poetry; and even regional and ethnic dialects.

Edward Stephan Klima was born in Cleveland on June 21, 1931. He earned a bachelor’s degree in linguistics from Dartmouth in 1953, followed by master’s and doctoral degrees in the field from Harvard in 1955 and 1965.

By the time Klima earned his Ph.D., linguistics had undergone a seismic upheaval. In 1957, a young scholar named Noam Chomsky had revolutionized the field. Language, Chomsky argued, was not simply learned social behavior, as scholars had long believed. Instead, it was the product of an inborn faculty — an instinct — unique to our species. Overnight, linguists had a new mandate: to describe this innate linguistic blueprint.

Hired by Chomsky in 1957, Klima taught at the Massachusetts Institute of Technology before joining the faculty at the University of California, San Diego, in 1967. There, with his wife, he began to investigate the biological underpinnings of a language without sound.

Raising questions

American Sign Language was first described as a real language only in 1960, when William Stokoe Jr., an English professor at Gallaudet College, was roundly derided for suggesting the fact. But if Stokoe was right, his idea raised tantalizing questions: How is sign language acquired by deaf children? How is it stored in memory? Which side of the brain controls sign language — the left hemisphere, where spoken language resides, or the right, which controls visual and spatial tasks?

To tackle these questions, Klima and Bellugi stripped away the acoustic veneer of spoken language — the consonant and vowel sounds on which it happens to rely — revealing underneath the mental machinery that drives all human language. Among their findings were these:

Like spoken language, sign language is acquired by young children in regular developmental stages. Like spoken language, it can break down as a result of strokes or other brain injuries. And, remarkably, despite its strong visual nature, sign language is controlled primarily by the left side of the brain. Sign language is language, Klima and Bellugi demonstrated, and at a basic neurological level, the brain knows it.

Their work is widely credited with helping American Sign Language gain broader acceptance as a language of instruction for deaf people and, by extension, with helping kindle the Deaf Pride movement, which began in the late 1980s.

Besides his wife, Klima is survived by two sons, Rob, of San Diego, and David, of Florence, Italy, and four grandchildren.