The ability to speak is one of the essential characteristics that distinguishes humans from other animals. Many people would probably intuitively equate speech and language. However, cognitive science research on sign languages since the 1960s paints a different picture: Today it is clear, sign languages are fully autonomous languages and have a complex organization on several linguistic levels such as grammar and meaning. Previous studies on the processing of sign language in the human brain had already found some similarities and also differences between sign languages and spoken languages. Until now, however, it has been difficult to derive a consistent picture of how both forms of language are processed in the brain.
Researchers at the MPI CBS now wanted to know which brain regions are actually involved in the processing of sign language across different studies—and how large the overlap is with brain regions that hearing people use for spoken language processing. In a meta-study recently published in the journal Human Brain Mapping, they pooled data from sign language processing experiments conducted around the world. “A meta-study gives us the opportunity to get an overall picture of the neural basis of sign language. So, for the first time, we were able to statistically and robustly identify the brain regions that were involved in sign language processing across all studies,” explains Emiliano Zaccarella, last author of the paper and group leader in the Department of Neuropsychology at the MPI CBS.
Read more: Medical Xpress