Hierarchical relations guide memory retrieval in sentence comprehension: Evidence from a local anaphor in Turkish

Real-time sentence comprehension relies on memory resources to establish long-distance syntactic dependencies. There is convincing evidence that formation of many dependencies is mediated by hierarchical constraints. However, it remains an open question how richly hierarchical information is represented and employed in memory processes. Here we ask whether hierarchical relations between noun phrases in a sentence as in x c-commands y (Reinhart, 1976) constrain antecedent retrieval for a local anaphor. We measure the real-time reactivation of c-commanding target antecedents and distractors in processing the Turkish reciprocal birbirleri via three visual world studies. Unlike existing studies that confounded multiple cues, we disentangled c-command from other structural information (clause-mateness, case, subjecthood) and linear order/recency. Experiment 1 compared the availability of c-commanding subjects and non-c-commanding, clause-mate, similarly case-marked distractors; and showed that c-commanding subjects were rapidly distinguished from distractors within the reciprocal window, irrespective of their linear order. Experiment 2 revealed that immediate availability of c-commanding subjects extends to c-commanding indirect objects. Experiment 3 was a pre-registered, high-power replication that yielded similar results. We found limited evidence for interference from distractors, which was not replicated. Overall, we find that hierarchical, item-to-item relations between noun phrases rapidly determine antecedent availability in retrieval beyond other cues. We suggest that hierarchical information may guide access to c-commanding items during retrieval if item representations include hierarchically informed features targeted by retrieval cues; alternatively, hierarchical information may shape the organization of items in memory, with c-commanding items represented in a privileged store allowing direct access during retrieval.