“If a lion could speak …”: Online sensitivity to propositional truth-value of unrealistic counterfactual sentences

Abstract

People can establish whether a sentence is hypothetically true even if what it describes can never be literally true given the laws of the natural world. Two event-related potential (ERP) experiments examined electrophysiological responses to sentences about unrealistic counterfactual worlds that require people to construct novel conceptual combinations and infer their consequences as the sentence unfolds in time (e.g., “If dogs had gills…”). Experiment 1 established that without this premise, described consequences (e.g., “Dobermans would breathe under water …”) elicited larger N400 responses than real-world true sentences. Incorporation of the counterfactual premise in Experiment 2 generated similar N400 effects of propositional truth-value in counterfactual and real-world sentences, suggesting that the counterfactual context eliminated the interpretive problems posed by locally anomalous sentences. This result did not depend on cloze probability of the sentences. In contrast to earlier findings regarding online comprehension of logical operators and counterfactuals, these results show that ongoing processing can be directly impacted by propositional truth-value, even that of unrealistic counterfactuals

Examining the cognitive costs of counterfactual language comprehension: Evidence from ERPs

“…These results provide further evidence that readers have set up a mental representation of the described counterfactual world, and can interpret events according to this plausible counterfactual world in the earliest moments of processing (e.g. Ferguson et al, 2010;Nieuwland, 2013;Nieuwland & Martin, 2012). Moreover, the fact that this pattern of inconsistency detection did not differ between the counterfactual-counterfactual and factual context conditions suggests that similar pragmatic constraints were activated by this counterfactual world as within a factual context.…”

“…Similar results have been found using unrealistic counterfactual sentences (e.g. "If dogs had gills, Dobermans would breathe underwater"), indicating that the ability to make counterfactual inferences does not rely on preexisting knowledge about reality (Nieuwland, 2013). Nieuwland (2012) has also presented evidence that different neural circuits might underlie these truth-value judgements for real-world and counterfactual-world utterances.…”

“…For example, paradigms that have examined counterfactual understanding within a single sentence (e.g. Nieuwland & Martin, 2012;Nieuwland, 2013) do not report any interference from the alternative world. These studies show that within a conditional if-then structure, readers immediately integrate the consequence of a counterfactual premise according to the sentence's overall propositional truth-value.…”

“…Similarly, N400 effects are activated when a narrative describes a character's inappropriate emotional response to a given social situation (Leuthold, Filik, Murphy, & MacKenzie, 2012), when a statement conflicts with a person's moral values (Van Berkum, Holleman, Nieuwland, Otten, & Murre, 2009), or when their actions mismatch their (false) beliefs (Ferguson, Cane, Douchkov, & Wright, in press). Importantly for the current study, plausibility effects have been shown to supersede typical sentence-level semantic anomaly responses within an appropriate counterfactual discourse (Nieuwland, 2013;Nieuwland & Martin, 2012). Thus, by comparing N400 amplitudes for world-consistent and world-inconsistent conditions we aimed to examine to what extent counterfactual and factual representations were being used to interpret the unfolding discourse.…”

The Truth Before and After: Brain Potentials Reveal Automatic Activation of Event Knowledge during Sentence Comprehension

“…Whereas sentence truth value N400 effects have often been observed for straightforward affirmative sentences (e.g., Nieuwland, 2013;Nieuwland & Martin, 2012;Hagoort et al, 2004;Kounios & Holcomb, 1992;Fischler et al, 1983), a substantial body of literature suggest that these effects do not always occur in sentences that contain negation operators or negative quantifiers such as "no" or "few" (e.g., Nieuwland, in press; Urbach Nieuwland & Kuperberg, 2008;Kounios & Holcomb, 1992;Fischler et al, 1983). In negative sentences like "A robin is not a tree," N400 amplitude is not reduced for true sentences compared to false sentences, and some older studies have reported N400 amplitude is not sensitive to negation at all (e.g., Kounios & Holcomb, 1992;Fischler et al, 1983).…”