Neural mechanisms of Event Visibility in sign languages
Abstract
Event structure in sign languages is reflected in the manual dynamics of verb production. As signed event structure is visible (iconic), non-signers are able to recognize it, despite having no sign lexicon. In this EEG study, hearing non-signers were presented with telic and atelic verb signs, followed by a lexical classification task in their native language. Behavioral data confirmed that non-signers classified both telic and atelic signs with above-chance accuracy. ERP waveforms indicated that non-signers identified the perceptual differences in motion features when viewing telic/atelic signs, and used different processing mechanisms when integrating the perceptual information with linguistic concepts in their native language. Non-signers appeared to segment visual sign language input into discrete events, as they attempted to map the observed visual forms to concepts, and label them linguistically. This mechanism suggests a potential evolutionary pathway for co-optation of perceptual features into the linguistic structure of sign languages.