For Deaf individuals, this question is integral to understanding the unique and complex systems at work in the language part of the brain. Sign language is neurological in the same way that spoken languages are. However, the brain processes sign language differently from spoken languages, which can impact the cognitive faculties of a Deaf individual (often for the better!).
Your Brain on Sign Language
Sign language engages the brain in unique ways. In short, signers use visual-spatial processing differently than audible speakers do. While some brain tissues trigger the same way among speaking and signing people alike, many differences point to the unique processing power required to sign.
Brocaโs Area
Brocaโs area is the region in the brain that processes spoken language. Located on the left part of the frontal lobe, Brocaโs area is responsible for a lot of what goes into language, like making comprehensible speech and aligning the muscles to create speech sounds. Brocaโs area is highly active anytime a person is speaking, but it quiets down when someone is not actively producing language.
Interestingly, for those who sign, Brocaโs area remains just as active as in those who speak. In other words, the brain treats sign language as exactly what it is: a language. Itโs not movement thatโs tied primarily to the kinesthetic parts of the brain; rather, the brain is processing it through the language production center.
In contrast, those who speak an audible language but are โlisteningโ (that is, watching) someone sign will interpret that speech in the right part of the frontal lobe, where movement processing is located. In this way, non-signersโ and signersโ brains are each adapted for the type of language that they speak!
The Right Frontal Lobe
Whatโs interesting about the way a signerโs brain works is that the frontal lobe is doing overtime. While itโs true that Brocaโs area is still in charge of the language of sign, the right frontal lobe (the movement region) is on high alert during signing conversations, too. This part of the brain is processing the movements of sign language in spatial relation, allowing for further context in conversations and adding increased dimension to utterances.
Does that mean that signersโ brains work harder during conversation? Yes! Those who sign see more activation of the frontal lobe than those who speak because both language processing and spatial recognition are involved at the same time. Thatโs why itโs common for Deaf people to outscore hearing people in tests of spatial awareness (though this does not necessarily mean that theyโre visual learners!).
The Brainโs Role in Language
Sign language speakers are impacted by language processing challenges in a similar fashion to voiced speakers; for instance, they may stutter in sign or when reading internally. Deaf signers who suffer strokes that damage Brocaโs or Wernickeโs areas see similar outcomes as speaking individuals: difficulty articulating thoughts, forming signs, spelling, and/or comprehending (depending on the area of the brain affected). Interestingly, damage to the right side of the brain seems to have minimal to no impact on signing, even though many motor functions are located there. This likely relates to the fact that so much of sign is brain-coded as language, not movement!
The Cognitive Benefits of Learning Sign Language
Sign language is a great brain workout, and learning it (especially when young or as a first language) offers numerous advantages. Some benefits are true anytime a person learns a second language, while others are more unique to sign specifically.
- Visual processing: As mentioned previously, those who sign are typically more attuned to visual information because their language skills reside not just in Brocaโs area, but in spatial-related regions of the brain, too.
- Vocabulary: Children who sign tend to learn words faster and maintain a more confident vocabulary because they directly connect tangible movements and identifiers to objects and ideas.
- Reading: Signers tend to read faster and with greater comprehension because fingerspelling primes the brain to process quickly on an alphabetical level.
- Cognitive plasticity: Like any second language, learning sign language in addition to another language boosts the brainโs ability to adapt, infer from minimal information, think critically, and recognize patterns. In fact, studies show that people who learn a second language may slow the onset of cognitive diseases such as dementia by as many as five years!
Remember: sign language isnโt a tool. Itโs a deeply embedded linguistic system in the brain, and itโs just as complex and extraordinary as any of the other myriad languages celebrated around the world!
