Sign languages are probably as old as spoken languages, if not older, though only in the past few centuries has it gained prominence. The first school for deaf children was founded by Abbé de l’Épée in 1755 Paris. Laurent Clerc, one of Épée’s graduates, would, along with Thomas Hopkins Gallaudet, go on to create the American School for the Deaf. This later became known as Gallaudet University, the only university in the world for deaf students. Movements like these brought sign language to public attention, although many deaf people still face prejudice because of it. While sign language has been used in research settings before, few studies have looked at recent trends in deaf culture. This paper/post aims to give a broad overview of sign language in general (with a slight bias towards American Sign Language), insights gained from research utilizing sign language, and what current trends are observed in Deaf community.
The greatest misconception facing sign language today is the view that they aren’t true languages like English, or French, or Swahili. This most probably results from the assumption that signing in sign language is merely mimicking the action one intends to convey. For those aware of sign language alphabets (using one or both hands), they may also presume that signing involves forming each letter and spelling out each sentence. Both of these, however, are far from the truth. Sign languages are just like oral languages in every respect, and this can be shown by analyzing what constitutes a language in the first place. Consider Baker-Shenk and Cokely’s universal definition of language:
A language is a system of relatively arbitrary symbols and grammatical signals that change across time and that members of a community share and use for several purposes: to interact with each other, to communicate their ideas, emotions, and intentions, and to transmit their culture from generation to generation. (31)
First, a language has symbols. In most languages, this takes the form of words that define something else. “House,” “fire,” “walk,” and “cat,” are examples in English; in sign languages, these are represented by their respective signs, a combination of hand and arm motions. Just as words can be further analyzed by breaking them down into their constituent phonemes (e.g. “cat” as “c”-”a”-”t”), so too can signs. ASL phonemes, however, are classified by the shape, location, movement, and orientation of the hands, a classification first proposed by William Stokoe (Sandler 3). Tied to this are grammatical signals, which indicate how these symbols are related and understood. In English (as well as Thai and Vietnamese, among others), word order is the grammatical signal that dictates the meaning of the sentence (i.e. “John ate carrots” and “Carrots ate John” do not mean the same thing). In other languages, however, word order is less important. Rather, it’s the inflections added to word endings that determine how a sentence is understood. This is the case with Russian, Finnish, Latin, and ASL. In Latin, for example, “Ioannes aspiciebat Petrum” and “Petrum Ioannes aspiciebat” are both acceptable ways of saying “John was looking at Peter”. In ASL, similar constructions are possible: J-O-H-N (right side) –LOOK-AT– (right to left) P-E-T-E-R (left side) and P-E-T-E-R (left side), J-O-H-N (right side) –LOOK-AT– (left to right) both state that “John was looking at Peter”. Here, the direction of the sign –LOOK-AT– defines who is the subject and who is the object. This does not, however, mean all permutations are possible; that would defeat the purpose of a grammatical signal.
Three more essential aspects of that definition are that language is a system; is shared among members of a community; and that the symbols themselves are relatively arbitrary. The first is evident of English and other languages, and should be evident of ASL as well. Although there may be a finite number of morphemes, there are an infinite number of constructions available. Moreover, language is limited shared among a community. Though this is easy to see for English, Spanish, Korean–indeed any language–it is commonly misperceived that there’s only one sign language. In actuality, however, sign languages are just as varied as spoken ones. British Sign Language (BSL), for one, is vastly different from ASL, even though they both evolved among English-speaking societies. ASL and Irish Sign Language are closely related to French Sign Language, while Australian Sign Language (Auslan) and New Zealand Sign Language (NZSL) are derived from BSL.
Sign languages also meet the property for having relatively arbitrary symbols, i.e. symbols that do not closely represent the object being described. Taiwan Sign Language uses an extended middle finger for “brother” and an extended fourth finger for “sister”. The sign for “tree” in Chinese Sign Language is just a vertical motion by both hands, the thumb and index fingers shaped like a “C”. The sign for “home” in ASL used to be the sign for “eat” followed by the sign for “bed”; now it has developed into a unique sign combining elements of “eat” and “bed”. This last example also shows how a sign language changes across time, akin to how oral languages evolve and differentiate. As for the final criterion–that language is used for several purposes–is self-evident for oral languages (heck, look at this paper/post) and, given their success in aiding deaf communication, should be equally self-evident for sign languages.
So far, all that has been looked at are linguistic specifications and corresponding examples. However, the medium through which sign languages convey information is quite different from that of oral languages. Is there corroborating biological evidence, then, that attests sign languages to be just as natural as spoken ones? The scientific evidence is compelling.
Hickok et al. published study in 1996 analyzing the linguistic capabilities of deaf signers who had lesions on either the left or right hemispheres of their brains. Thirteen left-lesioned subjects and 10 right-lesioned subjects–of varying ages with fairly consistent gender balance–were given an ASL-adapted version of the Boston Diagnostic Aphasic Examination, a three-hour test that focused on language production, comprehension, naming, and repetition. The authors speculated that since sign language relies on visual and spatial relationships, perhaps lesioning would not affect linguistic ability as much as it would in oral speakers. However, in every category, left-hemisphere lesioned patients did markedly worse than right-hemisphere lesioned patients. To control for overall cognition, a drawing test was administered, in which left-lesioned patients outperformed right-lesioned patients. The results strongly suggest that language treated the same way, regardless of whether it is spoken or not. In the authors’ own words:
These data indicate that at the hemispheric level the neural organization of sign language is indistinguishable from that of spoken language […] Taken together, these data suggest that left-hemisphere dominance for language is not driven by physical characteristics of the linguistic signal, but rather stem from higher-order properties of the system. (701-02)
Language is language, so it seems.
Another study supports this argument. In 2000, Petitto et al. published a study tackling this question in relation to particular sites in the left hemisphere responsible for analyzing language. The group analyzed regional cerebral blood flow (rCBF) in response to activity in the left inferior frontal cortex (LIFC), the planum temporale (PT), and the superior temporal gyrus (STG), which contains the PT. The LIFC is active in retrieving and generating spoken words; the PT processes phonemes and their relations within words and sentences; and the STG receives auditory input in relation to language. Brain activity was compared between deaf signers and hearing adults. Among the deaf participants, six were males, five were females, and all had been congenitally deaf. Some of the deaf participants learned ASL as their first language, while others learned Langue des Signes Québécoise (LSQ), a Canadian analogue of ASL. Five males and five females comprised the hearing participants. The data was obtained using positron emission tomography through the course of five distinct tasks. The data itself was highly technical, so it will not be dealt with here. The results from this experiment reinforce the theory of left-lateralization of language. Increased rCBF in the LIFC was observed in both hearing and deaf adults, implying a link between word and sign processing. Moreover, no significant differences were seen between ASL and LSQ signers, suggesting a rather generalized function of the LIFC. Although no evidence supported PT lateralization, what did surprise the researchers was increased activity in the STG itself in deaf signers. The STG had dogmatically assumed to have been receptive only to auditory stimuli, but increased activity among those born deaf–who had never heard a sound–challenges that notion. The authors speculate that “the cortical tissue in the STG may be specialized for auditory processing, but may undergo functional reorganization in the presence of visual input when neural input from the auditory periphery is absent” (13966). In other words, it seems that visual signs and motions replace sound, at least as perceived by the STG. The evidence here points towards a universal specialization for language within the left hemisphere of the brain.
Still, it seems fair to question left lateralization in deaf signers. After all, sign language relies heavily on visual cues and spatial relations, both of which (usually) are mediated by the right cerebral hemisphere. Shouldn’t some evidence exist of right-brain use in signers? As it turns out, the right hemisphere may have some interesting properties in deaf signers. A 2005 study by Pickell et al. (of which only the abstract is available) presented the case of sign language aphasia as a result of right hemisphere lesions. The abstract states that the subject “[exhibited] deficits in sign language comprehension and production typically associated with left hemisphere damaged signers. He also exhibits evidence of local versus global deficits similar to left-hemisphere lesioned hearing patients.” While he had been a life-long signer, the abstract brings attention to the fact that the he was left-handed. This naturally brings up the question of handedness and language lateralization, and if that had any effect on the finding itself. Even the Petitto et al. study emphasized that all participants were right handed.
Some digging around uncovered a 2000 report by Knecht et al. that posits a correlation between handedness and lateralization. Interestingly enough, the authors report that the question of handedness and language in the brain goes all the way back to Paul Broca, whose aphasia studies were only done on right-handed patients with left-hemisphere lesions. The “Broca rule” postulates that the reverse should be true, i.e. left-handed patients should show primarily right hemisphere language lateralization, even though Broca never said anything along those lines. The experiment was performed on 326 participants, of which 126 were male and 198 were female. Of note is the fact that only participants who had a high-school equivalent education were accepted. To measure the handedness of individuals, the Edinburgh Handedness Inventory was used (it’s really short, if you want to try it). Language lateralization was determined using functional transcranial Doppler ultrasonography, which gave results similar to functional MRI (fMRI). The results showed a fairly linear relationship between the degree of handedness and language lateralization. Of extreme right-handers, only 4% showed right-hemisphere lateralization, while 27% of extreme left-handers exhibited the same. The data showed a linear correlation between lateralization and handedness (Fig. 3):
Although there was a large gender gap, potentially skewing the results, the authors found that gender had little effect on lateralization. Moreover, the authors point out that
[…] subjects in whom the side of language dominance was the same as the side of dominance in the control of dexterity had stronger lateralization than those in whom these factors were dissociated: right-handers with left language dominance and non-right-handers with right language dominance displayed stronger overall lateralization than right-handers with right language dominance and non-right-handers with left language dominance. (2515)
What does this imply for the left-handed signer? His circumstances seem to fit the above findings, so it could just be that his handedness and right brain dominance are correlated. No reliable onclusions about sign language and hemisphere preference can be made here.
One study’s findings, however, partially contradict all the above-mentioned results. In a 2001 study, Newman et al. present data that certain areas in the right hemisphere are activated only by native signers of ASL. The participants were right-handed English-ASL bilinguals, 18 of whom learned ASL as a first language from deaf parents or relatives, and 11 non-native signers who learned ASL post-puberty in immersion environments. The native signers (NS) numbered 11 females and five males, while the late signers (LS) counted seven females and four males. The subjects were shown both coherent sentences and nonsense sentences (in written English as well as ASL) while an fMRI device scanned their brains. The results showed that, for written English, much activity was seen in the left hemispheres of both NS and LS, while virtually no activity was noticed in the right hemispheres of both groups. Presented with ASL sentences, however, both NS and LS showed bilateral activity. In the RH in particular, both groups showed activity in the anterior and middle superior temporal sulcus (STS), an area associated with language use. Only in NS, however, activity was also found in the anterior STS as well as the right angular gyrus. As the researchers conclude, this lends particular support to a critical period in ASL acquisition. Given the visuo-spatial nature of the language, right hemisphere activity should not be particularly surprising. What role the right angular gyrus plays, though, is much less clear. The authors suggest phonological or grammatical abilities may be its focus, or perhaps it responds to seeing human motion in general. In any case, whether sign languages are unilaterally or bilaterally specialized is an unresolved matter. Scientific data suggests both, a reasonable conclusion since it language itself seems too intricate to be resolved to one half of the brain. If that is the case with sign languages, perhaps it is the case for all languages in general. Lesion studies do show some plasticity between the hemispheres, with the right often taking some of the left’s duties in response to trauma. Perhaps language, then, is rooted deeper than once thought.
Sign languages are not just limited to cognitive science and neurobiology. Just as language can reveal details about how a culture perceives the world, so too can sign languages shed light on social microcosms. Spoken languages, however, reveal little about how languages in general are created and utilized. Whenever a “synthetic” language is created, such as by one person rather than arising naturally in a social context, it draws upon the learned linguistic structures of that one person, resulting in varying degrees of “authenticity,” so to speak. Esperanto, Klingon, and the languages of J. R. R. Tolkien are such constructed languages, which tend to select features of natural languages to create something naturalistic. Quenya, for example, was particularly based on Finnish, Greek, Latin, and some Romance languages. (If you are so intrigued, you can learn how to create your own language.) Since these languages provide nothing new, they do not give much insight on languages in general. This where sign language can play a crucial role. As has been stated before, there is no universal sign language; rather, sign languages appear only in a relatively sizeable deaf population. Small, remote groups of deaf people thus offer linguists a unique opportunity to observe the birth of a natural language. It can also address the controversial question of whether language is innate. After all, would a group of people, left alone, be able to come up with a working language?
Linguists were granted a unique opportunity to observe this almost thirty years ago. The setting was 1970s Nicaragua, then under the dictatorship of Anastasio Somoza Debayle. At the time, the deaf population had little voice. A sort of social stigma existed, and deaf children often stayed at home where they developed crude “homesigns” that they used within their own family. These would work out to crude words or phrases, nothing quite resembling a true language. The situation was radically changed following the 1979 Sandinista revolt. That same year saw the establishment of a new school for deaf children in Managua, where students went to learn Spanish. Deaf children now had an unprecedented opportunity to interact with similar peers. Spanish instruction was slow and making little progress, but the teachers noticed that while student-teacher communication was poor, students could communicate amongst each other quite successfully. It turns out that the children were meeting new, different homesigns and modifying them organically to create new signs for objects and phrases, such as “what’s up.” As they progressed, a vocational school for teenagers opened in 1981, where such signs became more codified and adapted. In 1986, American sign language researcher Judy Kegl was asked to come to Nicaragua to explain what had been going on. She first studied teenagers at the vocational school, who used simple gestures to describe objects or phrases. While the generation of novel signs is itself fascinating, what Kegl witnessed at the elementary school (San Judas) was far more stunning.
Whereas children growing up encounter difficulties and intricacies in spoken languages, the children at San Judas were practically inventing their own language. Some continuity of signs could be seen between the older generation and the younger one, but the younger kids had also modified and expanded the canon of signs. The fluidity and rapidity with which these children embraced the sign language made them, paradoxically, more fluent signers than the older teenagers, a finding consistent with critical periods of language acquisition. New grammatical constructions, such as verb agreement and inflection, were being seen. Nor was this new language led in any particular direction. Rather, each individual child contributed to the shaping of Idioma de Señas de Nicaragua (ISN, or Nicaraguan Sign Language). In this respect, sign language is clearly a social phenomenon, analogous to any other spoken language.
In a society where every member had never heard a sound, never had any significant exposure to spoken languages, ISN was the closest thing to a “pure” language, unrelated to any other language on Earth. Nonetheless, there was still some evidence of outside impact on ISN. On the most basic level, gestures used naturally by Spanish-speaking adults formed the basis for the adolescents’ signs, which in turn were passed to the elementary school children. What is particularly interesting is the way subsequent generations would alter these inherited signs (indicative of another feature of languages in general: constant change). A 2004 study by Senghas et al. looked at just how drastically these changes occurred over three different groups, or cohorts. The first group was exposed to ISN before 1984; the second, between 1984 and 1993; and the last, after 1993. Ten participants comprised each cohort while ten people made up a fourth group of Nicaraguan Spanish speakers. All four groups were shown a cartoon and asked to recount what had occurred. For Spanish speakers, only their gestures while speaking were analyzed. One particular example showed a cat that, after having swallowed a bowling ball, was rolling down the street. The Spanish speaker’s recap can be seen here, while the deaf child’s recap can be seen here. What struck the researchers in particular was the Spanish speaker’s use of a gesture that described both the direction and manner of motion. In contrast, the young child first signed the manner of motion, then indicated direction. Native speakers and the first cohort had more gestures and signs that defined manner and motion simultaneously, while the more recent cohorts had relatively few such expressions. What the researchers conclude is that young signers of ISN deconstruct the signs that they already see and combine them according to their individual parts. In the above example, it means making more signs, but it also creates a sort of vocabulary from which many more expressions can be created. In this process, these children have essentially formed their own phonemes. ISN is still a very young language, so how these signs will evolve is anyone’s guess. Other similar cases, such as with Al-Sayyid Bedouin Sign Language, are also garnering attention. In any case, the mere opportunity to observe such language growth in progress is quite exciting.
Sign language research is thus shedding light on a variety of topics. The most recent consideration involves bilingualism. Children naturally learn the language of their parents, so, unsurprisingly, children of deaf adults (codas) learn a sign language from early on. These children also pick up spoken languages as well, either from other hearing relatives or mass culture. Occasionally, however, codas blend aspects of sign language and spoken languages together. This hybrid language, called coda-talk, has a significant impact on how codas view themselves. In 2005, Bishop and Hicks presented the only in-depth study of codas and coda-talk available online. Many codas feel conflicted about having been raised with ASL, stating that “feel deaf,” despite perfectly fine hearing. Codas also inherit behavioral patterns of deaf people that hearing people may find awkward or uncomfortable, such as prolonged eye contact. Societal stigmas toward codas, and ASL in general, often lead codas to have negative thoughts about coda-talk. Such prejudices exist in any society with a bilingual population, and the authors assert that coda-talk is simply a “cultural identifier” of being a part of two spheres of society.
Bishop and Hicks give the following example as an early sample of coda-talk:
What must tell you, me find bad news. Father very sick, hospital, heart. Deaf part of me thinks deaf way. But me live in Hearing world, have hearing roommates, have hearing friends. All act like hearing people. At my house, hearing house. Me sit by phone. Alone. What happens when me tell hearing roommates, they walk out of room. Me find out hearing people think, something happen, your private business. Not ask questions. Me call hearing friends, please come over, need see you. One hearing friend say, busy, can’t but give phone support. Other hearing friend say, I have this block of time. Hearing time. This little block of time. Deaf way very different. Deaf come. In your face, ask, ask, ask. Want to know everything, A to Z. Important touch. We sit down. Discuss, group. Face to face. [From Preston (1994), p. 222]
In this case, the anecdote was simultaneously spoken and signed to other codas. For further analysis of coda-talk, the authors analyzed e-mails posted to a coda listserve. The most common deviations from standard English were dropped subjects, copulas (an auxiliary verb, like ‘is’ or ‘be’), and determiners (words like ‘some’ or ‘all’ describing noun phrases). Coda-talk also had some new elements as well, like new phrases and irregular infinitives. Examples of coda-talk follow (words in parentheses were dropped in coda-talk):
“So I am think”
“The bloody hotmail keeps to send”
“When he sing he have big vein and stick out on foreheads”
“I would be smile if went with you to see and hear”
“That nice”
“What I cooking?”
“They (did) not know”
“Hmmm, how (to) apply (for) that job?”
“Who want win lottery?”
“Ready [to] go”
“See family and give (them) big surprise”
“I am big excite” (205-07)
These examples show how visual signs augment written English, creating an unusual hybrid language. There are several interesting constructions involving the sign/word ORANGE as well, such as ORANGE-EYES = “Amazing!” Coda-talk also shows an overgeneralization with the letter s, an understanding of word reversals, and a new use for “the” (see Tables 11E, 11F, and 11G). The authors also presented a brief analysis of coda-talk over TDD and IRC, both of which tended to stick to English conventions rather than coda-talk. In either case, coda-talk is still a developing chimera. It tends to be personal, reserved only for codas. Perhaps with waning social stigmas, greater attention can be paid to coda-talk and its implications for bilingualism in general. For now, we can just sit back and let the language grow.
This paper/post has barely scratched the surface of sign language research. The Nicaraguan language studies will continue to map out how languages unfold over extended generations. Meanwhile, hopefully codas and coda talk will see rising interest, especially in their larger roles as bilinguals. Sign language as an institution is only tad bit younger than formal research on electricity, yet it has been vastly outpaced in terms of research depth. This is a shame considering many more people use language than electricity. Perhaps we just take language for granted. In any case, future sign language research should make psycholinguistics, sociolinguistics, and cognitive science very promising fields.
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References/Further Reading:
1. Baker-Shenk, C., & Cokely, D. (1996). What is a “Language”? In American Sign Language: A Teacher’s Resource Text on Grammar and Culture (pp. 31-46). Washington, D.C.: Clerc–Gallaudet University Press. (Original work published 1980)
2. Bishop, M., & Hicks, S. (2005, Winter). Orange Eyes: Bimodal Bilingualism in Hearing Adults from Deaf Families. Sign Language Studies, 5(2), 188-230. Retrieved December 6, 2006.
3. Hickok, G., Bellugi, U., & Klima, E. S. (1996, June 20). The neurobiology of sign language and its implications for the neural basis of language. Nature, 381, 699-702. Retrieved December 7, 2006.
4. Knecht, S., Dräger, B., Deppe, M., Bobe, L., Lohmann, H., Flöel, A., et al. (2000, December). Handedness and hemispheric language dominance in healthy humans. Brain, 123(12), 2512-18. Retrieved December 10, 2006.
5. Newman, A. J., Bavelier, D., Corina, D., Jezzard, P., & Neville, H. J. (2002, January). A critical period for right hemisphere recruitment in American Sign Language processing. Nature Neuroscience, 5(1), 76-80. Retrieved December 10, 2006.
6. Osborne, L. (1999, October 24). A Linguistic Big Bang. New York Times. Retrieved December 6, 2006.
7. Petitto, L. A., Zattore, R. J., Gauna, K., Nikelski, E. J., Dostie, D., & Evans, A. C. (2000, December 5). Speech-like cerebral activity in profoundly deaf people processing signed languages: Implications for the neural basis of human language. Proceedings of the National Academy of Sciences of the United States of America, 97(25), 13961-66. Retrieved December 10, 2006, from JSTOR database.
8. Pickell, H., Klima, E., Love, T., Kritchevsky, M., Bellugi, U., & Hickok, G. (2005, June). Sign language aphasia following right hemisphere damage in a left-hander: A case of reversed cerebral dominance in a deaf signer? Neurocase, 11(3), 194. Abstract retrieved December 7, 2006.
9. Sandler, W. (n.d.). Sign Language: An Overview. In Encyclopedia of Language and Linguistics (2nd ed.). Retrieved December 12, 2006.
10. Sandler, W., Meir, I., Padden, C., & Aronoff, M. (2005, February 15). The emergence of grammar: Systematic structure in a new language. Proceedings of the National Academy of Sciences of the United States of America, 102(7), 2661-65. Retrieved December 10, 2006.
11. Senghas, A., Kita, S., & Özyürek, A. (2004, September 17). Children Creating Core Properties of Language: Evidence from an Emerging Sign Language in Nicaragua. Science, 305(5691), 1779-82. Retrieved December 12, 2006.
12. Wade, N. (2004, September 21). Deaf Children’s Ad Hoc Language Evolves and Instructs. New York Times. Retrieved December 6, 2006.
