Negation Polarizes Agreement Dynamics During Sentence Comprehension

In a forced-choice mouse-tracking paradigm, true and false statements (ranging from very true, to ambiguous, to very false) were tested in both affirmative and negated forms. Replicating prior research, mouse trajectories reveal subtle differences in a continuum of true to false statements. However, negation modifies this process, particularly for very true statements (i.e. Bread is not made from sand). The mouse trajectories were more curved with negated sentences, with end-points of the continuum of truth (very true and very false statements) having the greatest area under the curve. The proposed explanation is the pragmatic meaning of a negated statement such as “Gummie bears are not alive” is infelicitous, whereas a true statement “People live on Earth” is felicitous. This study reveals the online dynamics of processing these statements and possible confusion, particularly when very true statements contain a negation.