Detecting falsehood relies on mismatch detection between sentence components

How do people process and evaluate falsehood of sentences? Do people need to compare presented information with the correct answer to determine that a sentence is false, or do they rely on a mismatch between presented sentence components? To illustrate, when confronted with the false sentence 'trains run on highways', does one need to know that trains do not run on highways or does one need to know that trains run on tracks to reject the sentence as false? To investigate these questions, participants were asked to validate sentences that were preceded by images (Experiments 1-3) conveying a truth-congruent or a falsehood-congruent component of the sentence (e.g., an image of tracks/highway preceding the sentence 'trains run on tracks/highways') or by words (Experiment 4) that were either sentence-congruent, truth-congruent, or both (e.g., the word 'train/tracks' preceding the sentence 'trains run on tracks/highways'). Results from four experiments showed that activating sentence-congruent concepts facilitates validation for both false and true sentences but that activating truth-congruent concepts did not aid the validation of false sentences. The present findings suggest that a detection of falsehood relies on a mismatch detection between sentence's components, rather than on the activation of true content in the context of a particular sentence.