title: Resolving sentence ambiguity with planning and working memory resources: Evidence from fMRI.
abstract: We used functional magnetic resonance imaging (fMRI) to test competing claims about the role of executive resources during the disambiguation of a sentence featuring a temporary structural ambiguity. Written sentences with a direct object (DO) structure or a sentential complement (SC) structure were shown to 19 healthy, right-handed, young adults in a phrase-by-phrase manner. These sentences contained a main verb that is statistically more likely to be associated with a DO structure or an SC structure. Half of each type of sentence also contained an extra phrase strategically located to stress working memory prior to disambiguating the sentence. We found that sentences featuring a less consistent verb-structure mapping recruit greater dorsolateral prefrontal cortex (dlPFC) activation than sentences with a more consistent verb-structure mapping, implicating strategic on-line planning during resolution of a temporary structural ambiguity. By comparison, we observed left inferior parietal cortex (IPC) activation in sentences with an increased working memory demand compared to sentences with a low working memory load. These findings are consistent with a large-scale neural network for sentence processing that recruits distinct planning and working memory processing resources as needed to support the comprehension of sentences.
authors.affiliation: Department of Bioengineering, University of Pennsylvania, USA.
authors.forename: Susana
authors.initials: S
authors.lastname: Novais-Santos
authors.forename: James
authors.initials: J
authors.lastname: Gee
authors.forename: Maliha
authors.initials: M
authors.lastname: Shah
authors.forename: Vanessa
authors.initials: V
authors.lastname: Troiani
authors.forename: Melissa
authors.initials: M
authors.lastname: Work
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D032882:Comprehension / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D011340:Problem Solving / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D011932:Reading; D012660:Semantics