Effects of delay, length, and frequency on onset RTs and word durations: Articulatory planning uses flexible units but cannot be prepared.

Abstract

There is debate regarding whether most articulatory planning occurs offline (rather than online) and whether the products of off-line processing are stored in a separate articulatory buffer until a large enough chunk is ready for production. This hypothesis predicts that delayed naming conditions should reduce not only onset RTs but also word durations because articulatory plans will be buffered and kept ready. We have tested this hypothesis with young control speakers, an aphasic speaker , and an age and education-matched speaker, using repetition, reading and picture-naming tasks. Contrary to the off-line hypothesis, delayed conditions strongly reduced onset RTs, but had no benefit for word durations. In fact, we found small effects in the opposite direction. Moreover, frequency and imageability affected word durations even in delayed conditions, consistent with articulatory processing continuing on-line. The same pattern of results was found in CS and in control participants, strengthening confidence in our results. There is debate regarding whether most articulatory planning occurs offline (rather than online) and whether the results of off-line processing are stored in a separate articulatory buffer until a large enough chunk is ready for production. This hypothesis predicts that delayed naming conditions should reduce not only onset RTs but also word durations because articulatory plans will be buffered and kept ready. We have tested young control speakers, an aphasic speaker, and an age and education matched speaker, using repetition, reading and picture naming tasks. Contrary to the off-line hypothesis, delayed conditions strongly reduced onset RTs, but had no benefit for word durations. In fact, we found small effects in the opposite direction. Moreover, frequency and imageability affected word durations even in delayed conditions, consistent with articulatory processing continuing on-line. The same pattern of results was found in CS and in control participants, strengthening confidence in our results.