Semantic and morphological effects in masked priming

Data from masked priming experiments have been used to support a traditional view of the mental lexicon where morphemes are stored discretely and complex words are decomposed in processing. In masked priming, visual primes are presented briefly and masked so to that subjects cannot consciously process them. This paradigm is generally considered insensitive to semantic effects. Thus, results showing greater facilitation for morphologically complex (cars-car) compared to orthographically overlapping prime-target pairs (card-car) are argued to arise from morphological rather than semantic factors. In contrast, in two experiments using a masked priming paradigm, we demonstrate that semantic similarity modulates priming: highly related items (hardly-hard: 30 ms) primed more than moderately related items (lately-late: 19 ms), while unrelated items did not prime (boldly-bold: -1 ms). Furthermore, very highly semantically related items with no form overlap (profit-gain) produced significant facilitation (21 ms). This surprising pattern of results suggests that semantic information is available very early on, even in the absence of conscious processing. Moreover, the graded priming effects support a view of morphology as an interlevel representation that mediates mappings between semantics and phonology and that emerges in the service of language acquisition and processing. On this view, morphology reflects structure present in the world: language input contains patterns that are picked up on by language learners to the extent that they are useful in solving the primary tasks of competent speakers, that is comprehending and producing speech.