Poster D57, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
An ERP Investigation of Repetition Priming Effects in American Sign Language: Time-locking to Dynamic Stimuli
Katherine J. Midgley1, Phillip J. Holcomb1, Karen Emmorey1; 1San Diego State University
In a previous study we reported that ERPs recorded to ASL signs in a repetition priming paradigm produced a similar pattern of effects as has been found for written and spoken words: larger N400s for unrepeated compared to repeated signs. However, the time course of this effect was substantially delayed and longer in duration than generally observed for written word repetition. Previous spoken word repetition effects show a prolonged N400 duration, but the N400 onset is generally early (~300 ms). For speech, acoustic information arrives dynamically, while for written words all of the visual information is available for processing simultaneously. Signs share attributes of both modalities, being dynamic in nature but delivering some phonological information simultaneously rather than sequentially. We tested the hypothesis that our original results were due to the dynamic and overlapping nature of information available in the signed signal. Specifically, we edited the 200 ASL videoclips from the previous ERP repetition experiment so that videoclips began two frames before the onset of the sign (as determined by native ASL signers), rather than from a rest position with the model’s hands in her lap. Nineteen deaf signers performed a go/no-go semantic categorization task, and forty items were repeated. As expected, the N400 repetition effect began substantially earlier than in the original study and in fact had a time course much like that seen in previous written word studies. Thus, the timing of the N400 effect for sign language crucially depends upon whether ERPs are time-locked to sign onset.
Topic Area: LANGUAGE: Lexicon