Hierarchical structure and memory retrieval mechanisms in agreement attraction

Speakers occasionally cause the verb to agree with an element that is not the subject, a so-called ‘attractor’; likewise, comprehenders occasionally fail to notice agreement errors when the attractor agrees with the verb. Cross-linguistic studies converge in showing that attraction is modulated by the hierarchical position of the attractor in the sentence structure. We report two experiments exploring the link between structural position and memory representations in attraction. The method used is innovative in two respects: we used jabberwocky materials to control for semantic influences and focus on structural agreement processing, and we used a Speed-Accuracy Trade-off (SAT) design combined with a memory probe recognition task, as classically used in list memorization tasks. SAT allowed us to investigate the full time-course of processing and it enabled the joint measurement of retrieval speed and retrieval accuracy. Experiment 1 first established that attraction arises in jabberwocky sentences, to a similar extent and following the same structure-dependency as in natural sentences. Experiment 2 showed a close alignment between the attraction profiles found in Experiment 1 and memory parameters. Results support a content-addressable architecture of memory representations for sentences in which nouns’ accessibility depends on their syntactic position, while subjects are kept in the focus of attention.