Faculty Collaboration Database

Some neurophysiological constraints on models of word naming. Neuroimage 2005 Sep;27(3):677-93

Date

06/01/2005

Pubmed ID

15921937

DOI

10.1016/j.neuroimage.2005.04.029

Scopus ID

2-s2.0-23744487069 (requires institutional sign-in at Scopus site)   199 Citations

Abstract

The pronunciation of irregular words in deep orthographies like English cannot be specified by simple rules. On the other hand, the fact that novel letter strings can be pronounced seems to imply the existence of such rules. These facts motivate dual-route models of word naming, which postulate separate lexical (whole-word) and non-lexical (rule-based) mechanisms for accessing phonology. We used fMRI during oral naming of irregular words, regular words, and nonwords, to test this theory against a competing single-mechanism account known as the triangle model, which proposes that all words are handled by a single system containing distributed orthographic, phonological, and semantic codes rather than word codes. Two versions of the dual-route model were distinguished: an 'exclusive' version in which activation of one processing route predominates over the other, and a 'parallel' version in which both routes are equally activated by all words. The fMRI results provide no support for the exclusive dual-route model. Several frontal, insular, anterior cingulate, and parietal regions showed responses that increased with naming difficulty (nonword > irregular word > regular word) and were correlated with response time, but there was no activation consistent with the predicted response of a non-lexical, rule-based mechanism (i.e., nonword > regular word > irregular word). Several regions, including the angular gyrus and dorsal prefrontal cortex bilaterally, left ventromedial temporal lobe, and posterior cingulate gyrus, were activated more by words than nonwords, but these 'lexical route' regions were equally active for irregular and regular words. The results are compatible with both the parallel dual-route model and the triangle model. 'Lexical route' regions also showed effects of word imageability. Together with previous imaging studies using semantic task contrasts, the imageability effects are consistent with semantic processing in these brain regions, suggesting that word naming is partly semantically-mediated.

Author List

Binder JR, Medler DA, Desai R, Conant LL, Liebenthal E

Author

Jeffrey R. Binder MD Professor in the Neurology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adolescent
Adult
Attention
Brain Mapping
Decision Making
Female
Fixation, Ocular
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Male
Memory, Short-Term
Middle Aged
Models, Neurological
Nerve Net
Psycholinguistics
Psychomotor Performance
Reaction Time
Reading
Speech