Document Type


Degree Name

Master of Science (MSc)




Faculty of Science

First Advisor

Todd Ferretti

Advisor Role

Thesis Supervisor

Second Advisor

Carol Madden

Advisor Role

Thesis Supervisor


The understanding of how temporal information constrains situation models is far from complete. In tehse two experiments participants read short stories, where the antecedent sentence was manipulated with respect to varying tense, grammatical and lexical verb aspect (Experiment 1), and then by varying grammatical and lexical verb aspect in conjunction with long and short duration events (Experiment 2). We used electrophysiological measures time-locked to the anaphoric referent to investigate how the brain responds to these temporal constraints. The purpose was to investigate teh possibility that these variables have an influence on the availability of discourse concepts in situation models. In Experiment 1, the anaphoric referent elicited a larger N400 when it was presented previously in a perfective antecedent sentence than an imperfective sentence. This N400 difference for grammatical aspect was limited to antecdent sentences with accomplishments as there was no statistical evidence for activities. Tense did not influence availability regardless of lexical aspect. In Experiment 2, N400 amplitudes were again modulated by grammatical aspect and this effect was also found to be limited to when antecedent sentences contained accomplishments. Furthermore, the results demonstrated that the imperfective advantage observed for accomplishments is not present after an intervening event with a long time shift. The implications of these findings are discussed in terms of theories of situation models.

Convocation Year