Poster D36, Wednesday, August 21, 2019, 5:15 – 7:00 pm, Restaurant Hall
Traveling back in time: does switching the focus to the initial state of the changed object come at a cost?
Yanina Prystauka1,2, Gerry Altmann1,2;1University of Connecticut, 2The Connecticut Institute for the Brain and Cognitive Sciences
The theory of Intersecting Object Histories (IOH; Altmann, & Ekves, 2019) postulates that events are “ensembles of intersecting object histories” and that the processing of a previously encountered object entails (at least transient) activation of its previous states, and these compete for selection. For example, the processing of the final "onion" in "The chef will chop the onion, and then she will smell the onion" entails activation of both the intact and the chopped states of the onion. fMRI evidence (Hindy, Altmann, Kalenik, &Thompson-Schill, 2012) suggests that such reactivation and competition manifest in increased activation in the brain area pVLPFC, recruited during Stroop interference, and this competition occurs regardless of whether the target state required by the context is the most recent (current) or the initial state of the object. Perhaps surprisingly, switching the focus from the current to the initial state (as in "The chef will chop the onion, but first she will smell the onion") didn’t elicit stronger conflict (and higher activation in VLPFC) than selecting the most recent state representation, although previous behavioral (Clark, & Clark, 1971; Mandler, 1986) and electrophysiological (Nieuwland, 2015; Politzer-Ahles, Xiang, & Almeida, 2017; Münte, Schiltz, & Kutas, 1998) research suggests that comprehending events described out of chronological order comes at increased processing cost. The current EEG study is aimed at directly testing whether reversing the order of events (via language) has consequences for the interplay between alternative object states. EEG was acquired while participants (N=24) read sentences presented to them one word at a time. In a 2 by 2 design, we manipulated the degree of change that the object underwent ("The chef will chop/weigh the onion") and the order of events ("and then/but first, she will smell the onion"). A time-frequency analysis of EEG power, time-locked to the sentence-final determiner phrase, revealed a stronger suppression of alpha/beta power in sentences describing substantial change ("chop") and presenting events in a chronological order ("and then") compared to all other sentences. This effect was most pronounced around 250-500 ms after the determiner onset. Such pre-target alpha/beta decreases have been associated with anticipatory processes and preparation for the input (Li, Zhang, Xia, & Swaab, 2017; Rommers, Dickson, Norton, Wlotko, & Federmeier, 2017; Piai, Roelofs, & Maris, 2014; Piai, Roelofs, Rommers, & Maris, 2015; Wang, Hagoort, & Jensen, 2018). This finding raises interesting questions regarding the constraining nature of state change verbs and their effect on downstream sentence processing. The fact that no such preparatory signal was observed in response to sentences describing events in reverse order ("but first") suggests that in such scenarios our comprehension system is less likely to assume that the unfolding language will refer back to the previously introduced object. To summarize, the interplay between the order in which the events were presented and the degree of change that the events entailed manifested in the anticipatory region as increased prediction for the substantial change & chronological order condition.
Themes: Meaning: Combinatorial Semantics, Control, Selection, and Executive Processes
Method: Electrophysiology (MEG/EEG/ECOG)