Magnetoencephalographic investigations of morphological identity and irregularity

This thesis addresses the longstanding debate in the psycholinguistics literature about the correct way to characterize the psychological status of morphological relatedness and irregular allomorphy. The model argued for here is one in which the mental lexicon consists of lexical roots (sound -meaning pairs that are arbitrary in the Saussurian sense, such as CAT: 'feline'<->/kaet/) and functional morphemes (affixes such as the plural marker -s, that carry purely grammatical information). Complex words are assembled by the grammar out of these roots and affixes. We argue that this is true even for words like "gaze" which don't clearly separate into two pieces, but are abstractly parallel to "walked," which does. Evidence for this full, across the board decomposition model is provided in a series of priming experiments that use magnetoencephalography to measure the earliest stages of lexical processing. Both regular and irregular allomorphs of a root are shown to access their root equally. These results, then, are incompatible both with connectionist models which treat all morphological relatedness as similarity, and with dual mechanism models which argue that regular allomorphy and irregular allomorphy arise from completely different systems, and only regular allomorphy involves root activation and composition. In this model, morphological relatedness is argued to be an identity relation between various allomorphs of a single, shared root, and is therefore clearly distinguished from semantic and phonological relatedness, which merely involve similarity between the meaning, or form, of different roots. The experiments reported in this dissertation support this model: the neural responses evoked by identity are significantly distinct from

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Linguistics and Philosophy.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Stockall, Linnaea C., 1975-

Advisor dc:contributor.advisor

• Alec Marantz.

• Linguistics and Philosophy.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/28833
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/28833

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28833