

On one neurocognitive dual-system view ( Ullman 2001a, 2004 Ullman et al. On a dual-system view, these distinct cognitive components also have distinct neural underpinnings ( Marslen-Wilson & Tyler 1998 Pinker 1991, 1999 Ullman 2001a Ullman et al. “Dual-system” theories posit that regular past tense forms are computed compositionally by a rule-governed mental grammar, whereas representations of irregular past tense forms are stored in and retrieved from lexical memory ( Clahsen 1999 Pinker 1991, 1999 Schreuder & Baayen 1995). This distinction between regular and irregular patterns has been explained in different ways. For example, although most English verbs are inflected in the past tense with the suffix –ed, a regular pattern that can be explained in a straightforward way by the combination of verb stem and suffix, a few hundred verbs are irregular: they do not seem to take the -ed suffix, and instead undergo a variety of a priori unpredictable changes to the stem. That is, there are typically exceptions to the predictable patterns that can be characterized by grammatical rules. The results suggest distinct neurocognitive substrates for processing regular and irregular past tense forms: regulars depending on compositional processing, and irregulars stored in lexical memory.Ī curious feature of natural human languages is that, in spite of their many regular patterns, “all grammars leak” ( Sapir 1921). Regular, irregular, and phrase structure violations all elicited later positivities that were maximal over right parietal sites (P600s), and which seem to index aspects of controlled syntactic processing of both phrase structure and morphosyntax.

These seem to reflect neurocognitive substrates that underlie compositional processes across linguistic domains, including morphology and syntax. Violations of regular past tense and phrase structure, but not of irregular past tense or lexical semantics, elicited left-lateralized anterior negativities (LANs). We recorded event-related potentials while participants read English sentences that were either correct or had violations of regular past tense inflection, irregular past tense inflection, syntactic phrase structure, or lexical semantics. lexical memorization), or whether a single processing system is sufficient to explain the phenomena, has engendered considerable investigation and debate. Whether regular and irregular forms depend on fundamentally distinct neurocognitive processes (rule-governed combination vs. For example, “irregular” English verbs have past tense forms that cannot be derived from their stems in a consistent manner. However, many complex linguistic forms have rather idiosyncratic mappings. For example, the past tense of most English verbs (“regulars”) is formed by adding an -ed suffix. These compositional patterns can generally be characterized by rules. It is found at numerous levels, including the combination of morphemes into words and of words into phrases and sentences. Compositionality is a critical and universal characteristic of human language.
