| |
Abstract:
Abstract: We investigated the neural basis for the regular
and irregular English past tense in two experiments using
high-density event-related potentials (ERPs), in a cross-modal
lexical decision paradigm. Across the two experiments we examined
ERPs to (i) visually presented regular and irregular verb roots,
primed auditorally by their past tenses, (ii) nouns primed by
semantically related words, and (iii) derivationally complex forms
primed by forms sharing the same derivational suffix. These were
compared to ERPs for unprimed targets of each type. The processing
of both types of primed verb was accompanied by a central parietal
positivity, also exhibited by the semantically primed targets, and
by a left anterior negativity (LAN), characteristic of linguistic
processing, and not shown by the semantically related pairs. The
scalp voltage distributions suggest that the LAN may have
originated from different brain sources for regular vs. irregular
verbs. The derivationally related pairs did not elicit the parietal
positivity but were associated with a left anterior negative, right
posterior positive complex. These results suggest that regular and
irregular past tenses have similar but not identical morphological
links to their stems, that this is not reducible to an underlying
semantic relationship, and that derivational and inflectional
morphology may engage different underlying systems.
|
