Poster E34, Friday, October 26, 3:20 – 5:20 pm, Kursaal Auditorium

Electrophysiological Evidence for Memory Retrieval during Referential Processing

Hossein Karimi1, Tamara Swaab1, Fernanda Ferreira1;1University of California, Davis

Referential processing involves linking referring expressions such as pronouns with preceding referential candidates. This linking process can be more or less difficult depending on: 1) how easy it is to find a unique referent for a pronoun (resolution difficulty) and 2) how easy it is to retrieve the memory representations associated with potential referents from memory (retrieval difficulty). This is because referential processing necessarily involves encoding the referential candidates in working memory and then retrieving those representations when a pronoun is encountered (e.g., MacDonald & MacWhinney, 1990). In this study, we asked whether retrieval difficulty can affect referential processing independent of resolution difficulty. Based on previous research showing that extra semantic information facilities subsequent retrieval (e.g., Hofmeister, 2011; Karimi & Ferreira, 2016), we varied the retrieval difficulty of referential candidates by manipulating whether they were modified by a relative clause or not, creating representationally rich or bare referential candidates, respectively, as illustrated in (1). A second sentence containing an ambiguous (Experiment 1) or an unambiguous (Experiment 2) pronoun such as (2) followed each version of the initial sentences. (1) Sentence 1 a) Bare Referential Candidates (baseline): The actor walked away from the cameraman/actress. b) Representationally Rich Referential Candidates: The actor who was visibly upset walked away from the cameraman/actress who was critical of the show. (2) Sentence 2: After a while, he realized it was getting late and took a taxi home. We measured Nref amplitudes to examine the effects of resolution and retrieval difficulty on the critical pronoun in Sentence 2. The Nref is a late, slightly left-lateralized, and sustained frontal negativity whose amplitude is modulated as a function of the difficulty associated with processing a referring expression; Nrefs with reduced amplitudes reflect easier referential processing (Van Berkum et al, 1999). By comparing two ambiguous or two unambiguous pronouns together, we kept resolution ambiguity constant such that any modulations on the amplitudes of the Nref could only be attributed to the representational richness, and by extension the retrieval difficulty, of the referential candidates. We observed smaller Nref amplitudes on ambiguous (Experiment 1) and unambiguous (Experiment 2) pronouns following representationally richer, and therefore easier-to-retrieve, referential candidates, suggesting that retrieval difficulty can affect referential processing independent of resolution difficulty. The results are consistent with recent research acknowledging the role of memory processes during referential processing in comprehension (e.g., Nieuwland & Martin, 2017) and lend support to cue-based retrieval theories of language processing, according to which retrieval difficulty should determine the processing difficulty of long-distance linguistic dependencies including referential dependencies (e.g., Lewis, Vasishth, & Van Dyke, 2006). Critically, the results also motivate a modification of what the Nref is commonly assumed to index. In particular, instead of solely reflecting resolution difficulty, the Nref appears to also index the ease with which the memory representations of referential candidates are retrieved from working memory.

Topic Area: Meaning: Discourse and Pragmatics

Back to Poster Schedule