The last linguistic similarity that hasn’t been discussed is the syntactic system. In spoken language, it is the order of words that provides for the primary organization of a sentence. For example, one can reverse the order of nouns of “Mary chased Beth” and end up with a new meaning of the sentence. Signers accomplish the same by pointing to a specific place in space while signing and link the word with that position, and it can also be reversed. (P.4 Hickok)
Linguistics is not the only way in which sign and spoken language are similar. Neither is a universal language, even though we all thought sign language was, but a deaf signer who acquires a second sign language; such as French or English, as an adult will sign with a foreign accent just as those that are bilingual in the spoken language do (P.3 Hickok). Both share abstract properties of the language, but their way of expressing it are different. A signer relies on visual-spatial changes to signal linguistic contrasts, where as a speaker encodes in acoustic-temporal changes and variations of sounds over time. With all these similarities and differences you can see that sign language is not merely just a manual version of spoken language, as many may think, but it is it’s own language just as Spanish, Italian and German are.
Sign language and spoken language seem quite different on the outside, but what about the inside? What’s happening in the brain, are they really all that different or are the more similar than we think? Does the brain produce spoken language from the same area that sign language is produced?
Gregory Hickok, Ursula Bellugi, and Edward Klima, are just a few of the people that have made an attempt at answering the question of where language comes from and more specifically where sign language originates at in the brain. In their article Sign language in the Brain, they attempt to answer this question by looking at the right and left hemispheres of the brain. They discuss many experiments that were done comparing those with right hemisphere- damage (RHD) to those with left hemisphere- damage (LHD) to see what each were able and unable to do. They tested those that signed and those that spoke with the abilities to comprehend making signs, and sentences, also to produce correct sounds and assemble appropriately the sounds. They wanted to see which part of the brain the left or right processes sign language, and whether they were the same as in spoken language.
Hickok’s article goes into detail trying to answer questions such as these. He discusses the right hemisphere and the left hemisphere, their jobs, what they are associated with and how each affects a person if it is damaged. When there is damage to the right hemisphere it rarely affects language, but when it does it is called aphasias. Moreover, the right hemisphere damage is associated mostly with severe visual and spatial problems, such as not being able to copy a line drawing (p.2 Hickok). This distinction lead researchers to believe that this is where sign language may be represented. The left hemisphere is said to be the verbal hemisphere, because those that have damage to this area have troubles, depending on the area, either speaking or comprehending speech.
When there is damage to the right hemisphere, signers are able to produce, with accurate signs, were able to use normal grammar and comprehend signs with much ease. They are able to communicate easily and effectively. The only problem that they tend to have is the ability to create or copy drawings and notice items in the left part of their visual field. In one study where there were 13 LHD signers and 10 RHD signers, the LHD signers preformed much worse than the RHD all around. The RHD signers preformed well on all the tasks given: they comprehended isolated signs and signed sentences fluently. They also had no difficulty naming tasks and made no slips of hand movements (p.5 Hickok) This study shows that Hickok may have been wrong in thinking that the right hemisphere was linked to sign language. It actually suggests that the left hemisphere is dominant for sign language. When looked from a linguistic view, we see that the patients whether singers or not that have damage to the left hemisphere have troubles assembling appropriate sounds and words when speaking. Those with RHD have troubles talking about one topic. They often ramble from one topic to the next with maybe one word connecting the topics. Although not all RHD patients have this problem, the cognitive systems in the right hemisphere that support non linguistic spatial abilities are different form the ones that support extended discourse.
Hickok did another test to investigate the role of Broca’s area in speech and sign production. They used noninvasive imaging techniques called functional magnetic resonance imaging (fMRI) and positron-emission tomography (PET) in order to probe the neural roots of language. They found that Broca’s area was activated in patients that were able to hear when they speak and it was also activated in deaf patients when they signed. This investigation lead researchers to hypothesize that sign language may be more bilaterally organized than spoken language. Since Hickok’s article was written there has been more research done on the topic and they have found the deaf’s process for communication is actually more similar to that of a hearing individual. The same brain scans that Hickok talked about have been used to show that similar areas are stimulated in deaf and hearing patients, when watching sign language or listening to speech. Researchers from Massachusetts, Boston suggest that the left planum temporale is not limited to processing sound, but that considerable overlap between regions of the brain are involved in proceeding spoken and signed language.
So where does language actually derive from, and are signed and spoken language coming form the same areas? We still are not sure. We do know that they have many similarities, and they activate a lot of the same sites in the brain. From Hickok we can say that maybe sign language uses both the left and the right hemispheres, and spoken only uses the left hemisphere, but in order to prove this hypothesis we have to do more research and work from the results that we are given. Sign language and spoken language are quite similar but their similarities are much the same as the similarities between French and Italian, Russian and Chinese. They are all languages and all have some similarities and differences. We know that they all originate from the brain and that we need additional research in order to determine where language comes from.
Works Cited
Hickok, Gregory. “Sign Language in the Brain.”
Proceedings of the National Academy of Sciences “Brain Processes Sign Language as Speech.” 2000; 97 http://www.brain.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=W&Product_Code=body_18410&Product_Count=0&Category_Code=senses