Computation of Semantic Number from Lexical, Morphological, and Conceptual Information

The distinction between singular and plural enters into linguistic phenomena such as morphology, lexical semantics, and agreement, and also must interface with perceptual and conceptual systems that assess numerosity in the world. Three experiments examined how the singular/plural distinction is extracted in real time from the morphological and lexical properties of visually presented words. In a Stroop-like task, Hebrew speakers were asked to determine the number of words presented on a computer screen (one or two) while ignoring their contents. People took longer to respond if the number of words was incongruent with their morphological number (e.g., they were slower to determine that one word was on the screen if it was plural, and in some conditions, that two words were on the screen if they were singular, compared to neutral letter strings), suggesting that the extraction of number from words is automatic and yields a representation comparable to the one computed by the perceptual system. In many conditions the interference occurred only with plural nouns, not singulars, consistent with the suggestion from linguistics that words lacking a plural affix are not actually singular in their semantics but unmarked for number. Interference by singular nouns occurs only in words whose meanings are inherently and saliently singular, such as “one” and “I.” For similar reasons, interference by plural nouns is attenuated when the referents of the plural noun are homogeneous, which encourages people to think of them as a mass or collection rather than an aggregate of individuals. The computation of number, therefore, is sensitive to information in lexical entries, morphological inflections, and the conceptual representations of individuals, aggregates, collections, or masses.