title: Higher Language Ability is Related to Angular Gyrus Activation Increase During Semantic Processing, Independent of Sentence Incongruency.
abstract: This study investigates the relation between individual language ability and neural semantic processing abilities. Our aim was to explore whether high-level language ability would correlate to decreased activation in language-specific regions or rather increased activation in supporting language regions during processing of sentences. Moreover, we were interested if observed neural activation patterns are modulated by semantic incongruency similarly to previously observed changes upon syntactic congruency modulation. We investigated 27 healthy adults with a sentence reading task-which tapped language comprehension and inference, and modulated sentence congruency-employing functional magnetic resonance imaging (fMRI). We assessed the relation between neural activation, congruency modulation, and test performance on a high-level language ability assessment with multiple regression analysis. Our results showed increased activation in the left-hemispheric angular gyrus extending to the temporal lobe related to high language ability. This effect was independent of semantic congruency, and no significant relation between language ability and incongruency modulation was observed. Furthermore, there was a significant increase of activation in the inferior frontal gyrus (IFG) bilaterally when the sentences were incongruent, indicating that processing incongruent sentences was more demanding than processing congruent sentences and required increased activation in language regions. The correlation of high-level language ability with increased rather than decreased activation in the left angular gyrus, a region specific for language processing, is opposed to what the neural efficiency hypothesis would predict. We can conclude that no evidence is found for an interaction between semantic congruency related brain activation and high-level language performance, even though the semantic incongruent condition shows to be more demanding and evoking more neural activation.
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping UniversityLinköping, Sweden; Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden; Department of Clinical and Experimental Medicine, Linköping UniversityLinköping, Sweden.
authors.forename: Helene
authors.initials: H
authors.lastname: Van Ettinger-Veenstra
authors.affiliation: Department of Clinical and Experimental Medicine, Linköping UniversityLinköping, Sweden; Division of Speech and Language Pathology, CLINTEC, Karolinska InstitutetStockholm, Sweden.
authors.forename: Anita
authors.initials: A
authors.lastname: McAllister
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping UniversityLinköping, Sweden; Radiation Physics, Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden; Radiology, Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Lundberg
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping UniversityLinköping, Sweden; Department of Behavioral Science and Learning and Linnaeus Centre HEAD, Linköping UniversityLinköping, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Karlsson
authors.affiliation: Center for Medical Image Science and Visualization (CMIV), Linköping UniversityLinköping, Sweden; Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Engström
keywords: angular gyrus; congruency; fMRI; inferior frontal gyrus; language ability; semantic processing; sentence reading