Rule-based versus associative processes in derivational morphology

The present article examines whether derivational morphology shows evidence of an associative memory structure. A distributional analysis of stems of attested derivational forms revealed evidence of clustering around phonological properties (gangs) for all nonneutral affixes but only a few neutral affixes. Subjects ’ acceptabil-ity ratings for novel complex words revealed sensitivity to the gang structure associ-ated with the relevant derivational affixes. Results suggest that, like inflectional morphology, derivational morphology shows dissociations between rule-based and associative generalization mechanisms. ª 1999 Academic Press Key Words: morphology; gang effects; derivation; connectionism; dual model; associative memory. One of the most hotly debated issues in recent years is whether certain linguistic processes can be captured within single associative networks that eschew symbolic representations and rules (e.g., Bybee, 1995; Rumelhart & McClelland, 1986; Skousen, 1992; Stemberger, 1995). Much of the debate has been addressed to the distinction between regular and irregular inflec-tions. Challenging the single-network models, Pinker (1991) presented evi-dence that regular and irregular inflections show multiple dissociations that support a distinction between rule-based and associative processes for regu-lar and irregular inflections respectively. According to Pinker’s dual model, a rule-based process is a default opera-tion that concatenates an affix, such as-ed, with a variable standing for syn-tactic category of the stem. It thus applies freely to any item of the righ