Neural correlates of fine-grained meaning distinctions: An fMRI investigation of scalar quantifiers

Abstract

Communication involves successfully deriving a speaker's meaning beyond the literal expression. Using fMRI, it was investigated how the listener's brain realizes distinctions between enrichment-based meanings and literal semantic meanings. The neural patterns of the Mandarin scalar quantifier you-de (similar to some in English) which implies the meanings not all and not most via scalar enrichment, with the specific quantifier shao-shu-de (similar to less than half in English) which lexico-semantically encodes the meanings not all and not most, were compared. Listeners heard sentences using either quantifier, paired with pictures in which either less than half, more than half, or all of the people depicted in the picture were doing the described activity; thus, the conditions included both implicature-based and semantics-based picture-sentence mismatches. Imaging results showed bilateral ventral IFG was activated for both kinds of mismatch, whereas basal ganglia and left dorsal IFG were activated uniquely for implicature-based mismatch. These findings suggest that resolving conflicts involving inferential aspects of meaning employs different neural mechanisms than the processing based on literal semantic meaning, and that the dorsal prefrontal/basal ganglia pathway makes a contribution to implicature-based interpretation. Furthermore, within the implicature-based conditions, different neural generators were implicated in the processing of strong implicature mismatch (you-de in the context of a picture in which "all" would have been true) and weak implicature mismatch (you-de in the context of a picture in which "most" would have been true), which may have important implications for theories of pragmatic comprehension. Hum Brain Mapp 38:3848-3864, 2017. © 2017 Wiley Periodicals, Inc.

Keywords: fMRI; picture-sentence verification; pragmatics; scalar implicature; semantics.

Figure 1

(A) demonstrates the experimental procedure. (B) shows the behavioral results for each critical condition in the online picture–sentence consistence rating. Error bars represent ±1 standard error of the mean.

Figure 2

(A) shows different type of mismatch effect in bilateral IFG and Basal Ganglia, and beta values in these regions under six conditions. S, strong; W, weak; M, match. (B) reveals the correlation between the behavioral rating difference and the beta value difference in the dorsal LIFG, under the weak‐implicature versus strong‐implicature contrast.

Figure 3

PPI results under different contrast. (A) shows increased connectivity between ventral RIFG/LBG and bilateral STG, under the strong‐implicature mismatch versus implicature match contrast. (B) shows the decreased connectivity between dorsal LIFG and right SFG, and response‐modulated increased connectivity between dorsal LIFG and left IPL, under the weak‐implicature mismatch versus implicature match contrast. (C) shows the increased connectivity between ventral RIFG and left STG, under the strong‐semantic mismatch versus semantic match contrast. [Color figure can be viewed at http://wileyonlinelibrary.com]