Connecting Phonological Encoding To Articulation - Is Cascading Required? A Computational Investigation

Current psychological models of word production (e.g. Dell, 1986; Levelt, Roelofs, & Meyer, 1999) only detail how we plan the phonological content of words, and not how we articulate them. To understand how these models may be extended, we must determine how information flows from phonological encoding to articulation. For example, does activation cascade from unselected phonological representations? So far, the clearest support for cascading at this interface has come from the finding that erroneously produced phonemes exhibit characteristics of the intended phoneme (Goldrick & Blumstein, 2006). In this paper however, we use computational implementations to demonstrate that both cascading and non-cascading models can account for this result. An extension of model behaviour analysis to other speech error phenomena additionally shows that models based on the classic spreading activation account of word production (Dell, 1986) experience problems in replicating some key aspects of human error patterns.