Date of Graduation


Document Type


Degree Name

Master of Arts in Psychology (MA)

Degree Level



Psychological Science


William Levine

Committee Member

Denise Bieke

Second Committee Member

Brenda Zies


Psychology, Activation, Negation, Presupposition


Research on the mental representation of negated concepts in written texts has yet to reach a consensus about the effects of negation. MacDonald and Just (1989) reported that after reading a sentence with a negation, negated words took longer to recognize than non-negated words, which suggests that the negated concepts became less active. However, Hasson and Glucksberg (2006) found that after reading negative metaphors (e.g., This surgeon isn't a butcher), lexical decisions about words consistent with the affirmative sense of the negated word (e.g., clumsy) took less time than for control words. To reconcile these (and other) incompatible findings, two experiments were conducted to test the possibility that the findings of MacDonald and Just do not persist beyond immediate testing. Experiment 1 used a probe task and materials similar to those used by MacDonald and Just, with the addition that the probe task occurred either 0 ms, 500 ms, or 1000 ms after the end of the sentence. The negation effect was present at 0 ms, replicating MacDonald and Just, but not at 500 ms or 1000 ms. This finding is consistent with the hypothesis that the reduced activation seen from negation out of context is short-lived. Experiment 2 used an eye-tracking procedure to provide converging evidence for the effect of additional processing time. However, the hypotheses were not supported.