Research from three universities in the UK, published in the journal Nature, reveals that deaf people who use Sign Language have better and more detailed long-term visual memory than hearing people.
Science had already proved that deaf signers outperformed hearing non-signers in attention, visual discrimination and short-term visual memory (i.e. seconds). Now, researchers from three UK universities (Northumbria University, Heriot-Watt University and University College London) wanted to know whether deaf Sign Language users also have better visual long-term memory. The conclusion is yes, and the results were published in 2022 in the world's most prestigious scientific journal: Nature.
The Experiment
The research was approved by the Research Ethics Committee of the Faculty of Social Sciences, Heriot-Watt University. It involved 20 deaf people (10 women and 10 men) and 20 hearing people (11 women and 10 men). Of the deaf people, 17 were deaf from birth and three acquired deafness before the age of 2, all of whom were bilingual in English and British Sign Language (BSL).
The participants completed different tests: ability to remember fine details of pictures, short-term memory, face discrimination, a sensory imagery questionnaire and an autobiographical memory questionnaire.
For example, in the task of scene discrimination: participants completed a total of 40 scene discrimination trials. In each trial, a different pair of photos of complex real-world scenes (e.g., the countryside) was presented. The pairs of photos presented were either identical or contained two fine differences and participants had to look for possible differences between the two photos and press the space bar on the computer keyboard when they spotted a difference.
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| Photo: Craig, Dewar, Turner, Collier, & Kapur 2022 |
In the long-term test, explained very simply, participants underwent three phases: in the first phase (A) they were presented with 50 pictures of everyday objects. In the second phase (B), they had to complete the scene discrimination test for 10 minutes. In the third phase (C), they were presented with 25 of the above objects along with 25 slightly different and 25 completely new objects, and had to identify which were the same, different and new.
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| Photo: Craig, Dewar, Turner, Collier, & Kapur 2022 |
Results
The results of the research showed that deaf signers not only outperformed hearing non-signers in long-term visual memory, but also demonstrated a superior ability to remember small visual details.
In addition, the research showed, once again, that deaf signers were superior to hearing people in discriminating scenes.
The researchers do not yet know why deaf people have better memory quality, although it is possible that it is because deaf people encode visual information differently from hearing people, something they will continue to investigate in the future.
What Is This For?
Beyond the simple observation of the power of Sign Languages to transform our perception of the world, researchers themselves point out that these superior abilities could represent a niche for deaf people as "super recognisers" in the police force. For example, the case of the recruitment of 20 deaf people by the police in Oaxaca (Mexico) for crime prevention through camera surveillance is well known (see detailed article here). Finally, they also believe that this benefit could be extended to the health and education fields.
Source:
- Craig, M., Dewar, M., Turner, G., Collier, T., & Kapur, N. (2022). Evidence for superior encoding of detailed visual memories in deaf signers. Scientific Reports, 12(1), 1-9. Retrieved from https://www.nature.com/articles/s41598-022-13000-y
