Research

Ohio State Dissertations in Linguistics (OSDL)

Jennifer Vannest (2001)

Morphological Effects in Visual Word Processing: Their Timecourse and Consequences for Lexical Architecture

Advisor: Keith Johnson

Download .pdf file [PDF]

Abstract:

Dual-route models of morphological processing, such as the Morphological Race Model of Schreuder & Baayen (1995) or the Augmented Addressed Morphology Model of Caramazza et al (1988) suggest that language users access many types of affixed words from the mental lexicon either as whole-word units or morpheme-by-morpheme. Certain linguistic factors determine whether a given affixed word is better processed by one route or the other: for example, suffixes that are phonologically neutral, share the same form with freestanding words, or are inflections rather than derivations may be more likely to trigger morpheme-by-morpheme "decompositional" processing. This suggests that for different affixes, there also may be differences in the timecourse of whole-word and morpheme-based processing.

The existing models and the experiments used to test their predictions (mainly lexical decision experiments), however, have been generally unable to make claims about this timecourse. In order to address this issue, we examined some English derivational suffixes and an inflectional suffix in four experiments by modifying a standard visual lexical decision or naming experiment base (root word) and surface (whole-word) frequency, where base frequency effects are assumed to reflect decompositional processing. This setup was combined with a Speed-Accuracy Tradeoff design: participants learned to make lexical decisions or name words after a delay of 150-700 ms. At the end of the delay, a response cue was given, and participants were trained to respond within 300 ms after the signal and were given feedback on each trial regarding their speed. Frequency effects on response times and error rates showed a somewhat different pattern in these results than in the traditional completely subject-paced design: in general, both the base and surface frequency effects that were found (variably across the different suffixes) appeared when response delays were short and disappeared when delays were longer. The combination of effects has interesting implications for dual-route models of morphological processing, and here we propose the Dual-Route Decay model, a more refined version of the existing models that takes into account the timecourse of accessing complex words from the mental lexicon.