In recent years, scientists have invested research into sensory functions in deaf people. Deaf people who know a form of sign language characteristically have enhanced vision according to a recent study conducted by researchers from the University of Sheffield’s Academic Unit of Ophthalmology and Orthoptics.
The same study indicates that deaf people who are able to communicate using sign language also have better reaction times than hearing people, regardless of whether or not those hearing people are fluent in sign language.
The researchers who conducted the study gathered 17 deaf adults, 18 hearing adults and eight interpreters of British Sign Language to participate.
Most participants from the deaf group were deaf from birth. Others went deaf sometime along the course of their lives due to a disease or an accident. Each participant from the deaf and interpreter groups understood and used British Sign Language as a primary mode of communication.
Researchers selected each of the participants based on the fact that none of them had played video games prolifically, which may have impacted reaction time.
To test for both peripheral vision and reaction time, researchers asked participants to keep their eyes unstrained and lax while focusing on a vantage point. LED lights were placed sparingly along a uniformly gray background. The task was to click a button on a joystick that corresponded to the location of each LED light when lit up.
Prior to beginning the process, researchers gave clear instructions to each participant in either English or British Sign Language. Joystick operations were also demonstrated to each user. The test accounted for the results of only one eye at a time—each participant wore a patch over one eye throughout the entire examination. A few participants submitted the results of only the right eye.
In order to ensure that participants had understood and retained the original instructions, researchers had asked them to complete a trial run in which they also moved the joystick to the position that corresponded to the location of the LED light.
The speed at which each participant toggled the joystick to indicate the position of the flashing LED light indicated reaction time. However, the results from the right eye demonstrate some variation in reaction time in comparison to the results from the left eye.
Through comparison of the results across all fields and constraints within the study, researchers concluded that deaf people had a significantly faster reaction time compared to their hearing counterparts. However, interpreters who understood British Sign Language recorded faster reaction times than hearing adults who did not have any experience with British Sign Language.
The results indicate that interpreters who did not learn British Sign Language as their native tongue still developed their periphery and motor skills through practice over the years. These sensory functions, when strongly developed, can be incredibly beneficial to applied tasks such as athletics or driving.
The results can also account for a stronger basis for hiring deaf adults in mechanical and hands-on fields that otherwise may not see a large deaf population. Deaf people should be encouraged to work in job sectors that must be maintained and operated by people who have exceptional reaction times.
The results also confirm the theory that losing one sense can cause other senses to heighten. In this case, the deaf adults demonstrated better reaction time and periphery vision than their hearing counterparts, which indicates that upon losing their sense of hearing, their vision and motor skills became enhanced.
It is important to note that interpreters who achieved significantly better results than hearing adults who did not understand British Sign Language were exposed to and were fluent in the language for a minimum of six years. This allowed for the development of visual sensitivity in each participant.