Negative polarity in quantifiers evokes greater activation in language-related regions compared to negative polarity in adjectives

The processing of sentences with negative quantifiers (e.g., few) is more costly than of sentences that contain their positive counterparts (e.g., many). While this polarity effect is robust and reliably replicable, its neurological bases are not well understood. In this study, we use functional magnetic resonance imaging (fMRI) paradigm for 30 participants to assess the polarity effect in sentences with polar quantifiers, and compare it with the polarity effect of polar adjectives. Both in quantifiers and in adjectives, the polarity effect manifests in the anterior insula bilaterally. The polarity effect in quantifiers, however, shows greater activation in the left hemisphere than it does for adjectives. In particular, left inferior frontal gyrus (IFG) and left superior temporal sulcus (STS) show increased activation for polarity in quantifiers than in adjectives, which is the evidence for the specific involvement of the language network in this type of polarity processing. Using the polarity effect in adjectives as a control, we provide further evidence for the linguistic complexity that negative quantifiers implicate on processing.