Cognitive Sequelae of Atypical Sign Language Development
This study investigated how the language deprivation experienced by deaf children of hearing parents has an impact on higher order cognitive abilities compared to those raised by deaf parents. This study focused on the executive functions that are responsible for optimal learning and social behavior. The Color Trails Test was administered to deaf children and adults. This test required them to connect numbered circles sequentially while alternating the circles’ colors (line from a pink circle with the number 1 to a yellow circle with the number 2 while ignoring the pink circle with the number 2 and so on). The task requires cognitive flexibility to shift attention while inhibiting distractors. The time it took participants to complete the task was recorded.
The results illustrated that deaf children and adults raised in language improvised environments and are not exposed to a signed language until after the age of 3 or older perform worse on this executive function task compared to deaf individuals who were raised by parents who are fluent in a sign language. These results highlight the importance of high quality language experiences early in life for optimal cognitive development later in life. The results also have practical implications for early intervention programs for deaf infants and toddlers.