Electrophysiological evidence for use of the animacy hierarchy, but not thematic role assignment, during verb-argument processing

Abstract

Animacy is known to play an important role in language processing and production, but debate remains as to how it exerts its effects: (1) through links to syntactic ordering, (2) through inherent differences between animate and inanimate entities in their salience/lexico-semantic accessibility, and (3) through links to specific thematic roles. We contrasted these three accounts in two event-related potential (ERP) experiments examining the processing of direct object arguments in simple English sentences. In Experiment 1, we found a larger N400 to animate than inanimate direct object arguments assigned the Patient role, ruling out the second account. In Experiment 2, we found no difference in the N400 evoked by animate direct object arguments assigned the Patient role (prototypically inanimate) and those assigned the Experiencer role (prototypically animate), ruling out the third account. We therefore suggest that animacy may impact processing through a direct link to syntactic linear ordering, at least on postverbal arguments in English. We also examined processing on direct object arguments that violated the animacy-based selection-restriction constraints of their preceding verbs. These violations evoked a robust P600, which was not modulated by thematic role assignment or reversibility, suggesting that the so-called semantic P600 is driven by overall propositional impossibility, rather than thematic role reanalysis.

Keywords:

• Animacy hierarchy
• Thematic roles
• Event-related potentials
• Sentences

Acknowledgements

Gina R. Kuperberg was supported by NIMH (R01 MH071635) and NARSAD (with the Sidney Baer Trust). We thank Evan C. Ruppell for his help developing experimental sentences and assisting in running participants in the ERP portion of the study. We are also grateful to Phil Holcomb, Ray Jackendoff, David Caplan, and Neal Pearlmutter for helpful comments on earlier versions of this manuscript.

Notes

¹There has been extensive discussion within the linguistic community about the exact nature of thematic roles/relations. Here we take a position influenced by Jackendoff (1987), who stated that “thematic relations are to be reduced to structural configurations in conceptual structure; the names for them are just convenient mnemonics for particularly prominent configurations” (p. 378). Thus by Agent, we refer to any argument that describes the entity which causes an action to happen, while a Patient is an entity which is affected by the action. We do not consider more fine-grained distinctions such as between an Agent and Causer, or Patient and Theme.

²In the current study, critical direct object arguments were followed by function words.