A neural signature of phonological access: Distinguishing the effects of word frequency from familiarity and length in overt picture naming (2007)
| Venue: | Journal of Cognitive Neuroscience |
| Citations: | 16 - 2 self |
BibTeX
@ARTICLE{Graves07aneural,
author = {William W. Graves and Thomas J. Grabowski and Sonya Mehta and Jean K. Gordon},
title = {A neural signature of phonological access: Distinguishing the effects of word frequency from familiarity and length in overt picture naming},
journal = {Journal of Cognitive Neuroscience},
year = {2007},
pages = {617--631}
}
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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 repre-sentation. We performed functional magnetic resonance imag-ing (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 pur-pose 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 fre-quency 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 pro-duction in which lexical–semantic and lexical–phonological in-formation are accessed by overlapping neural systems within posterior and anterior language-related cortices, with pSTG spe-cifically involved in accessing lexical phonology. &
Keyphrases
word frequency overt picture phonological access neural signature word length processing cost concept familiarity articulatory-motor routine lexical semantic representation left inferior frontal gyrus word frequency effect whole-word phonological representation left posterior inferotemporal lexical phonological in-formation lower-frequency word high name agreement cognitive model word pro-duction primary motor region overt naming response manipulable object conjoint effect word production phonological word form familiarity effect level-dependent response functional magnetic resonance imag-ing word fre-quency neural structure anterior language-related cortex neural system conjoint frequency left posterior superior temporal gyrus phonological repre-sentation lexical semantic expected word frequency effect lexical phonology articulatory load scan-time response latency fmri data parallel analysis parametric approach
