Negation induced forgetting: Investigating potential boundary conditions

In four experiments, we investigated the negation-induced forgetting effect. Participants first saw a video of an apartment showing several objects and their properties. In a subsequent verification task, participants verified true or false affirmative or negative statements by responding with yes or no . After a distractor task, participants completed a final recognition test for the objects. Forgetting rates were higher for objects that in the verification phase had been mentioned in statements requiring a no- response compared to objects that had been mentioned in statements requiring a yes- response (Experiment 1). A comparable effect was obtained for objects that in the verification phase had been mentioned in negated vs. affirmative verification statements (Experiment 2). To test whether this effect depends on the semantic scope of negation, Experiment 3 placed the critical object outside the scope of the negation operator by embedding it in a non-restrictive relative clause. Contrary to the prediction of a strictly scope-based account, this manipulation did not provide conclusive evidence that negation-induced forgetting disappears when the object falls outside the semantic scope of negation. Finally, the detrimental effects on memory of no-responses and sentence negation did not combine additively (Experiment 4). Together, these findings suggest that negation-induced forgetting is not specific to the response particle no but generalizes to sentence polarity more broadly. Furthermore, the absence of additive effects suggests that the effects of the response particle no and sentence negation are unlikely to reflect two independent inhibitory mechanisms. At the same time, our findings indicate that semantic scope alone does not fully account for negation-induced forgetting, leaving open whether the underlying mechanism reflects scope-insensitive conceptual inhibition, the influence of more surface-level linguistic representations, or a combination of both.