On the Processing of Novel Root+suffix Combinations

New words are constantly entering language. When a new word is formed by the combination of existing morphemes, it is expected to follow languagespecific structural patterns called selectional restrictions. If a new word follows these restrictions, then it can be considered to be morphologically legal, and if it violates these restrictions, then it can be said to be morphologically illegal. For example, in English, the derivational suffix -ify combines with nouns to form verbs, as in classify (class+ify). While not attested in English, a word like bird+ ify should be morphologically possible, because it does not violate the selectional restrictions governing the use of the suffix –ify. However, the form bird+ment violates the selectional restrictions of the suffix –ment, which combines with verbs to form nouns with a general meaning of ‘state’ or ‘action,’ and does not typically combine with nouns. If selectional restrictions play a role in word formation, one would expect novel words following selectional restrictions to be more acceptable to native speakers than morphological illegal pseudowords. There is evidence that derivational suffixes have mental representations beyond their occurrences in derived words. Reid and Marslen-Wilson (2003) reported a suffix-suffix interference effect when participants were presented with different suffixes attached to the same stem in a prime-target pair. This is taken as evidence that suffixes have independent representations in the mental lexicon. Hay (2001) demonstrated that the relative frequencies of the base, affix, and derived form of a word can influence whether the complex derived form will be decomposed. This requires that the base and suffix that make up a derived form interact, which in turn suggests that suffixes themselves have their own representations in the mental lexicon and accompanying statistical properties that are worthy of consideration. The interactions of roots and affixes have not been fully explored. In the following series of experiments, selectional restrictions and family size were both considered as possible influences on the processing of novel root+suffix combinations in English.