No abstract

Humans have a striking capacity to combine words into sentences that express new meanings. Previous research has identified key brain regions involved in this capacity, but little is known about the time course of activity in these regions, as hemodynamic methods such as fMRI provide little insight into temporal dynamics of neural activation. We performed an MEG experiment to elucidate the temporal dynamics of structure and content processing within four brain regions implicated by fMRI data from the same experiment: the temporo‐parietal junction (TPJ), the posterior temporal lobe (PTL), the anterior temporal lobe (ATL), and the anterior inferior frontal gyrus (IFG). The TPJ showed increased activity for both structure and content near the end of the sentence, consistent with a role in incremental interpretation of event semantics. The PTL, a region not often associated with core aspects of syntax, showed a strong early effect of structure, consistent with predictive parsing models, and both structural and semantic context effects on function words. These results provide converging evidence that the PTL plays an important role in lexicalized syntactic processing. The ATL and IFG, regions traditionally associated with syntax, showed minimal effects of sentence structure. The ATL, PTL and IFG all showed effects of semantic content: increased activation for real words relative to nonwords. Our fMRI‐guided MEG investigation therefore helps identify syntactic and semantic aspects of sentence comprehension in the brain in both spatial and temporal dimensions.

No abstract

Memory access mechanisms such as cue-based retrieval have come to dominate theories of the processing of linguistic dependencies such as subject-verb agreement. One phenomenon that has been regarded as demonstrating the role of such mechanisms is the grammaticality asymmetry in agreement attraction, which is the observation that nouns other than the grammatical controller of agreement can influence the computation of subject-verb agreement in ungrammatical, but not grammatical, sentences. This asymmetry is most often accounted for via the dynamics of retrieval interference. We challenge this interpretation, arguing that the asymmetry largely reflects response bias. Three forced-choice judgment experiments show that neutralizing response bias results in a decrease in the size of the grammaticality asymmetry, or its elimination altogether. Together with the response time patterns in these experiments, this result favors an account that attributes attraction effects to a continuous and equivocal representation of number, rather than to the dynamics of retrieval interference. We implement a model of grammaticality judgments that links a continuous representation of number to the rate of evidence accumulation in a diffusion process. This model accounts for the presence or absence of the grammaticality asymmetry through shifts in the decisional starting point (i.e. response bias), and highlights the importance of monitoring for response bias effects in judgment tasks.

There is ongoing debate about the role that resumptive pronouns play in the processing of islands in intrusive resumption languages such as English. This squib provides evidence that resumptive pronouns facilitate the comprehension of islands in online processing. The results fall in line with filler-gap processing more generally: when fillers are difficult or impossible to keep active, resumption provides support for forming a dependency. This occurs when dependencies span multiple clauses, when memory resources are otherwise taxed, or, as the present paper shows, when grammatical constraints such as islands prohibit the use of the active filler strategy.