Processing scalar implicatures in conversational contexts: An ERP study

Scalar expressions are words that have both a semantic meaning (e.g., the semantic meaning of “some” is “more than one”) and a pragmatic meaning (e.g., the pragmatic meaning of “some” is “some but not all”). The majority of experimental research on scalar terms has focused on the quantity expression “some” and its use in nonconversational contexts. In contrast, in this research we examined five different scalar expressions that were embedded in a conversational context with varying degrees of face-threat. Participants read scenarios followed by a target utterance containing a scalar expression in the first half of the utterance (e.g., some), with a second half continuation of the utterance containing either the pragmatic meaning (e.g., not all) or the semantic meaning (e.g., all). ERPs in response to the scalar term and subsequent meaning were examined. Neural responses to the scalar term did not vary as a function of face-threat. However, the semantic meaning resulted in a larger P300 than did the pragmatic meaning, a difference that was greater when the situation was face-threatening than when it was not face-threatening. This pattern did not vary over the five different scalar expressions and suggests that in conversational contexts, it is the pragmatic meaning that is expected.