Conditional root uniqueness points: Psychological validity and perceptual consequences

Wurm (1997) introduced a construct called the Conditional Root Uniqueness Point (CRUP), which was defined as the uniqueness point of the free root of a prefixed word, given the prefix in question. Prefixed words with free roots can be divided into two mutually exclusive categories: those with the CRUP at the same phoneme as the full-form uniqueness point (UP), and those where the CRUP precedes the full-form UP by one or more phonemes. Results of two reaction-time experiments indicate a substantial processing advantage for the latter group of words. Regression analyses revealed effects of the number of auditory competitors a target word had, semantic transparency and prefix likelihood. Finally, semantic transparency, root frequency, and number of competitors had different effects, depending upon whether the CRUP of a word coincided with or preceded the full-form UP. Existing models of word recognition need to be modified to accommodate the current results.