Heather Knapp: The time course of lexical access in American Sign Language production

Abstract

The retrieval and consolidation of the various linguistic components of words during lexical access is of interest to those who seek to model the hierarchical structure of the mental lexicon. Speech errors provide evidence for compositional rather than holistic lexical storage and retrieval but fail to provide any information about the time course of the process. One method of studying the time course of lexical access during language production is through an interference paradigm in which reaction times are measured as subjects name ordinary objects in the face of interfering orthographic or auditory linguistic stimuli (IS). Typically these stimuli are semantically, morphologically, or phonologically similar to the target picture. Manipulation of the temporal asynchrony between the onsets of targets and IS reveals that naming latencies vary as a function of the presentation order and the linguistic nature of the interfering stimulus. Specifically, semantically related IS delay picture naming when presented just before or at the same time as the onset of the picture, while phonologically related IS expedite picture naming when presented at the same time as or up to 250 msec after the onset of the picture. While these findings are robust in the spoken language literature, to date no work has been reported on the time course of lexical access in the production of signed languages. Although spoken and signed languages are perceived and produced through different sensory and motor channels, we expect that the temporal order of lexical access is similar in the two modalities. In this experiment, we measured picture naming latencies of native users of American Sign Language (ASL). Interfering stimuli were signed lexical items that were phonologically related, semantically related, phonologically and semantically related, or unrelated to the target picture. We varied the relative order of sign and picture onsets and assessed how reaction time varies as a function of IS condition and order of presentation. These data will provide insight into the time course of lexical access in American Sign Language production and speak to some similarities and differences in how auditory and visual languages might be stored and accessed.