Journal article
A neural signature of phonological access: distinguishing the effects of word frequency from familiarity and length in overt picture naming
Journal of cognitive neuroscience, Vol.19(4), pp.617-631
04/2007
DOI: 10.1162/jocn.2007.19.4.617
PMID: 17381253
Abstract
Cognitive models of word production correlate the word frequency effect (i.e., the fact that words which appear with less frequency take longer to produce) with an increased processing cost to activate the whole-word (lexical) phonological representation. We performed functional magnetic resonance imaging (fMRI) while subjects produced overt naming responses to photographs of animals and manipulable objects that had high name agreement but were of varying frequency, with the purpose of identifying neural structures participating specifically in activating whole-word phonological representations, as opposed to activating lexical semantic representations or articulatory-motor routines. Blood oxygen level-dependent responses were analyzed using a parametric approach based on the frequency with which each word produced appears in the language. Parallel analyses were performed for concept familiarity and word length, which provided indices of semantic and articulatory loads. These analyses permitted us to identify regions related to word frequency alone, and therefore, likely to be related specifically to activation of phonological word forms. We hypothesized that the increased processing cost of producing lower-frequency words would correlate with activation of the left posterior inferotemporal (IT) cortex, the left posterior superior temporal gyrus (pSTG), and the left inferior frontal gyrus (IFG). Scan-time response latencies demonstrated the expected word frequency effect. Analysis of the fMRI data revealed that activity in the pSTG was modulated by frequency but not word length or concept familiarity. In contrast, parts of IT and IFG demonstrated conjoint frequency and familiarity effects, and parts of both primary motor regions demonstrated conjoint effects of frequency and word length. The results are consistent with a model of word production in which lexical-semantic and lexical-phonological information are accessed by overlapping neural systems within posterior and anterior language-related cortices, with pSTG specifically involved in accessing lexical phonology.
Details
- Title: Subtitle
- A neural signature of phonological access: distinguishing the effects of word frequency from familiarity and length in overt picture naming
- Creators
- William W Graves - University of IowaThomas J Grabowski - University of IowaSonya Mehta - University of IowaJean K Gordon - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of cognitive neuroscience, Vol.19(4), pp.617-631
- DOI
- 10.1162/jocn.2007.19.4.617
- PMID
- 17381253
- ISSN
- 0898-929X
- eISSN
- 1530-8898
- Grant note
- R33 EB001484 / NIBIB NIH HHS F31 DC007560 / NIDCD NIH HHS R01 DC006633 / NIDCD NIH HHS
- Language
- English
- Date published
- 04/2007
- Academic Unit
- Communication Sciences and Disorders
- Record Identifier
- 9984258849102771
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