The sign superiority effect: Lexical status facilitates peripheral handshape identification for deaf signers

Deaf signers exhibit an enhanced ability to process information in their peripheral visual field, particularly the motion of dots or orientation of lines. Does their experience processing sign language, which involves identifying meaningful visual forms across the visual field, contribute to this enhancement? We tested whether deaf signers recruit language knowledge to facilitate peripheral identification through a sign superiority effect (i.e., better handshape discrimination in a sign than a pseudosign) and whether such a superiority effect might be responsible for perceptual enhancements relative to hearing individuals (i.e., a decrease in the effect of eccentricity on perceptual identification). Deaf signers and hearing signers or nonsigners identified the handshape presented within a static ASL fingerspelling letter (Experiment 1), fingerspelled sequence (Experiment 2), or sign or pseudosign (Experiment 3) presented in the near or far periphery. Accuracy on all tasks was higher for deaf signers than hearing nonsigning participants and was higher in the near than the far periphery. Across experiments, there were different patterns of interactions between hearing status and eccentricity depending on the type of stimulus; deaf signers showed an effect of eccentricity for static fingerspelled letters, fingerspelled sequences, and pseudosigns but not for ASL signs. In contrast, hearing nonsigners showed an effect of eccentricity for all stimuli. Thus, deaf signers recruit lexical knowledge to facilitate peripheral perceptual identification, and this perceptual enhancement may derive from their extensive experience processing visual linguistic information in the periphery during sign comprehension. (PsycInfo Database Record (c) 2020 APA, all rights reserved).