The processing of various attributes of verbs is crucial for sentence comprehension. Verb attributes include the number of complements the verb selects, the number of different syntactic phrase types (subcategorization options), and the number of different thematic roles (thematic options). Two functional magnetic resonance imaging experiments investigated the cerebral location and pattern of activation of these attributes. Experiment 1 tested the effect of number of complements. Experiment 2 tested the number of options of subcategorization and of thematic frames. A group of mismatch verbs with different number of options for subcategorization and thematic frames was included to distinguish between the effects of these attributes. Fourteen Hebrew speakers performed a semantic decision task on auditorily presented sentences. Parametric analysis revealed graded activations in the left superior temporal gyrus and the left inferior frontal gyrus in correlation with the number of options. By contrast, the areas that correlated with the number of complements, the right precuneus and the right cingulate, were not conventionally linguistic. This suggests that processing the number of options is more specifically linguistic than processing the number of complements. The mismatch verbs showed a pattern of activation similar to that of the subcategorization group but unlike that of the thematic frames group. By implication, and contrary to claims by some linguists, subcategorization seems indispensable in verb processing.

Making inferences beyond the literal meaning of sentences occurs with certain scalar expressions via scalar implicatures. For example, adults usually interpret some as some but not all. On the basis of behavioral research, it has been suggested that processing implicatures is cognitively costly. However, many studies have used cases where sentences with some did not match the context in which they were presented. Our study aimed to examine whether the processing cost is linked to implicature generation, to the mismatch between the implicature and the context, or to both processes. To do so, we explored the neural patterns of implicature generation and implicature mismatch using fMRI. Thirteen participants performed a sentence-picture matching task (where pictures determined the context) with mismatched implicatures, successful implicatures or no implicature conditions. Several brain regions were identified when comparing cases of implicature mismatch and cases without implicatures. One of these regions, left-IFG, was jointly activated for mismatched and successful implicatures, as observed in a conjunction analysis. By contrast, left-MFG and medial-frontal-gyrus, were identified when comparing cases of implicature mismatch with cases of successful implicatures. Thus, the left IFG can be interpreted as being linked to implicature generation, whereas the other two areas seem to participate in the processing of the mismatch between the implicature and its context. Our results indicate that scalar implicatures induce processing cost in different ways. This should be considered in future research.

No abstract

Unaccusative verbs like fall are special in that their sole argument is syntactically generated at the object position of the verb rather than at the subject position. Unaccusative verbs are derived by a lexical operation that reduces the agent from transitive verbs. Their insertion into a sentence often involves a syntactic movement from the object to the subject position. To explore the neurological reality of the distinction between different verb types and to identify the cortical activations associated with the lexical and syntactic operations, we compared unaccusative verbs with verbs that do not undergo such operations--unergatives (verbs with one argument, an agent) and transitives (verbs with two arguments). The observed pattern of activation revealed that the brain distinguishes between unaccusative and unergative verbs, lending neurological support for the linguistic distinction. A conjunction analysis between the comparisons between unaccusatives and the other verb types revealed activations in the left inferior frontal gyrus and the left posterior middle temporal gyrus. These, together with previous neuroimaging results, suggest that the inferior frontal gyrus may be involved with the execution of the syntactic operation, whereas the middle temporal gyrus may be responsible for the lexical operation that derives unaccusative verbs.