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Investigating determiner meanings using time-resolved decoding in EEG
Poster Session E, Friday, October 2, 11:00 am - 1:00 pm, Wangari Maathai
This poster is part of the Sandbox Series.
Xiaoyu Yang1; 1University of Maryland, College Park
In this study, we collect EEG data during comprehension of sentences like 'Each/Every circle is red' and 'All/Some of the circles are red' and use time-resolved decoding to test hypotheses about the roles of the determiner's first vs. second arguments (‘circle’ vs. ‘red’) in meaning construction. Knowlton et al. (2020, 2023a) found that when people evaluate sentences containing 'every' against visual stimuli, only objects specified by its first argument are represented as a group (e.g. the circles), but not those specified by its second argument (e.g. the red objects). Based on this evidence, they proposed that determiner meanings take the first argument to define a restrictive domain, and the second argument to provide a predicate to be applied to domain member(s). We hypothesize that comprehension of such sentences thus consists of two operations, (1) the formation of the restrictive domain and (2) the predication of domain members, which are carried out serially during the incremental processing of the noun phrase and the predicate respectively. Here we test this hypothesis by using neural responses as an index of the timing of these operations. We predict that differences in determiner meaning that affect the first operation should result in decodability of the determiner from neural responses to the first argument (‘circle’). For this we make use of the contrast between 'each' vs. 'every', which has been found to motivate individual vs. group representations of the specified objects (Knowlton et al., 2022a, 2022b, 2023b). In contrast, since 'all' and 'some' differ in quantificational force, i.e. quantities to be predicated of, our hypothesis predicts that this difference affects the second operation and leads to different neural responses and thus determiner decodability only during the predicate (‘red’). The experiment comprises four determiner blocks - each, every, all, some - each containing 80 sentences presented with RSVP using a 600 ms SOA. Sentences in the 'each' and 'every' blocks have the structure 'DET SHAPE is COLOR' (e.g. 'Each circle is red'), and those in the 'all' and 'some' blocks have the structure 'DET of the SHAPEs are COLOR' (e.g. 'All of the circles are red'). 20% of the trials are followed by a memory probe (sentence recognition), and another 20% by a visual quantification probe screen containing various shapes of different colors, where participants are asked to estimate the number of objects specified by either the noun phrase or the predicate. We conduct two pairwise multivariate decoding analyses, one for the each/every pair and one for the all/some pair. Each uses a binary logistic regression classifier trained at each time point throughout the noun phrase and the predicate to separate the two relevant determiner conditions. Data collection and analysis are underway.
Topic Areas: Syntax and Combinatorial Semantics,