The brain basis of syntactic processes: functional imaging and lesion studies

Abstract

Language comprehension can be subdivided into three processing steps: initial structure building, semantic integration, and late syntactic integration. The two syntactic processing phases are correlated with two distinct components in the event-related brain potential, namely an early left anterior negativity (ELAN) and a late centroparietal positivity (P600). Moreover, ERP findings from healthy adults suggest that early structure-building processes as reflected by the ELAN are independent of semantic processes. fMRI results have revealed that semantic and syntactic processes are supported by separable temporofrontal networks, with the syntactic processes involving the left superior temporal gyrus (STG), the left frontal operculum, and the basal ganglia (BG) in particular. MEG data from healthy adults have indicated that the left anterior temporal region and the left inferior frontal region subserve the early structure building processes. ERP data from patients with lesions in the left anterior temporal region and from patients with lesions in the left inferior frontal gyrus support this view, as these patients do not demonstrate an ELAN, although they do demonstrate a P600. Further results from patients with BG dysfunction suggest that parts of this subcortical structure are involved in late syntactic integrational processes. The data from the different experiments lead to the notion of separable brain systems responsible for early and late syntactic processes, with the former being subserved by the inferior frontal gyrus and the anterior STG and the latter being supported by the BG and more posterior portions of the STG.

Context-dependent interpretation of words: Evidence for interactive neural processes

“…Yet many sentence processing studies have argued that the middle temporal gyrus is involved in semantic integration processes consistent with the second interpretation of the results (Friederici and Kotz, 2003;Kuperberg et al, 2005;Baumgaertner et al, 2002). Although it is possible that PMTG processes both combinatorial and lexical semantic aspects of verbs, more evidence is required.…”

Native and non-native reading of sentences: An fMRI experiment

“…The shift of focus within STG to more posterior portions in response to written sentences may reflect slower, more controlled integration processes for written than spoken sentences. Such an interpretation would be supported by work coming from patient studies, showing that lesions in the posterior portion of the temporal lobe hamper late integration (Friederici and Kotz, 2003). It is suggested that the anterior STG supports the establishment of phrase structure expectancies, which are not fulfilled upon encountering a grammatically impossible word in a previously established sentence structure.…”

“…The anterior portion of the STG has been shown to come into play, in particular, when syntactic aspects during auditory sentence processing are required (Friederici et al, 2000a). The finding that the anterior STG is involved in on-line syntactic processing in the auditory domain is, moreover, supported by a lesion study indicating that fast syntactic processes are missing in patients with lesions in the anterior portion of the temporal lobe (Friederici and Kotz, 2003) and by an MEG study in which the fast syntactic processes were reflected by two dipoles in the left hemisphere, one of which was located in the anterior STG (Friederici et al, 2000c). The shift of focus within STG to more posterior portions in response to written sentences may reflect slower, more controlled integration processes for written than spoken sentences.…”

“…When these expectancies are not fulfilled (template matching), activation in STG is observed. It has been suggested based on electrophysiological studies with patients that posterior portions of the STG may work together with structures of the basal ganglia to support controlled processes of syntactic integration (Friederici and Kotz, 2003).…”

Language structure in the brain: A fixation-related fMRI study of syntactic surprisal in reading

“…Specifically, we were interested in the nature of the cortical systems that compute syntactic representations during online language comprehension. Three regions have traditionally been identified as candidates for syntactic processing (Fedorenko et al, 2012;Friederici and Kotz, 2003;Grodzinsky and Friederici, 2006;Kaan and Swaab, 2002). Historically, Broca's area or left inferior frontal gyrus (IFG) has been most associated with syntax (Ben-Shachar et al, 2003;Ben-Shachar et al, 2004;Bornkessel-Schlesewsky et al, 2009;Caplan et al, 2008;Caplan et al, 2000;Carramazza and Zurif, 1976;Dapretto and Bookheimer, 1999;Embick et al, 2000;Friederici et al, 2006;Grodzinsky, 2001;Just et al, 1996;Santi and Grodzinsky, 2007;Stromswold et al, 1996).…”