Deaf News: Native sign language users process visual body movements faster, Gallaudet study suggests

Native American Sign Language (ASL) users require less effort to understand human motions and can process them faster than hearing non-signers – according to research carried out by Gallaudet University.

Academics at the American institution, which is a private university for Deaf and hard of hearing people, created 18 point-light displays (PLDs) of figures carrying out everyday movements, including from different angles.

Both Deaf and hearing participants were asked to rate how easy it was to recognise the actions depicted, of which some were scrambled. The figures revealed that Deaf participants reported a lower mean average for difficulty (1.76), in comparison to hearing raters (2.39).

“From our online study, self-reported effort in identifying PLDs showed that deaf signers reported less difficulty than hearing non-signers in identifying what actions were represented by the PLDs.

“We suggest that the reduced effort required to distinguish these actions may be due to deaf signers’ long-term experience with extracting and producing meaning through their own and other people’s movements, even in visual environments when the meaning is difficult to extract (e.g., a visually noisy environment). It is also possible that being deaf, regardless of sign language use, plays a role in this effect.

Do deaf signers see differently? Do they perhaps see some things more easily?

In our paper, we show that yes–there is "enhanced perception of biological motion in deaf native signers"! 🧵

(@GallaudetU @Jasonlamby @steministemily @AthenaNeuro) pic.twitter.com/JzH9qyzJS4

— Lorna Quandt // lornaquandt on BlueSkyy (@lornaquandt) August 30, 2021

“A recent paper asked, ‘What and how does the deaf brain see?’ and with the results presented here we propose […]: the brain of a deaf native sign language user more readily sees and understands non-linguistic human biological motion, even when presented in a degraded form and from non-canonical perspectives.” the article, published in the Neuropsychologia journal, reads.

The research also involved electroencephalograms (EEGs) – a record or test of a person’s brain activity involving electrodes placed on a person’s scalp – which found that in contrast to hearing non-signers, Deaf signers “might be quickly engaging […] processes involved in memory retrieval while observing biological motions”.

“In a separate EEG study, sensorimotor EEG of deaf native signers displayed earlier and more robust differentiation between Biological and Scrambled PLDs when compared to the hearing non-signers. Taken together, the data suggests that deaf signers more readily process human biological motions,” the report goes on to add.

The authors concluded that further research should look into processing amongst deaf people who do not know sign language and hearing sign language users “of varying proficiencies” in order to “more completely describe this phenomenon”.

The full article is available to read online via the ScienceDirect website.

Photo: Fakurian Design/Unsplash.

By Liam O’Dell. Liam is a Deaf freelance journalist and campaigner from Bedfordshire. He can be found talking about disability, theatre, politics and more on Twitter and on his website.